Novel Carvedilol Analogs that Suppress Store Overload Induced Ca²⁺ Release

Abstract

Carvedilol is a uniquely effective drug for the treatment of cardiac arrhythmias in patients with heart failure. This activity is in part due to its ability to inhibit store overload-induced calcium release (SOICR) through the RyR2 channel. We describe the synthesis, characterization and bioassay of ca. 100 compounds based on the carvedilol motif in order to identify features that correlate with and optimize SOICR inhibition. A single cell bioassay was employed based on the RyR2-R4496C mutant HEK-293 cell line, in which calcium release from the endoplasmic reticulum through the defective channel was measured. IC₅₀ values for SOICR inhibition were thus obtained. The compounds investigated contained modifications to the three principal subunits of carvedilol, including the carbazole and catechol moieties, as well as the linker chain containing the β-amino alcohol functionality. The SAR results indicate that significant alterations are tolerated in each of the three subunits.

Introduction

Ventricular arrhythmias are a leading cause of sudden death, particularly in patients with heart failure. Consequently, a variety of antiarrhythmic drug therapies have been evaluated in clinical trials, which revealed only limited survival benefits.^1–3 Antagonists of β-adrenergic receptors (β-blockers) have been of special interest in these studies, as overstimulation of these receptors can trigger fatal ventricular arrhythmias.^4–6 The underlying mechanism of this process involves, in part, an overload of Ca²⁺ in the sarcoplasmic reticulum, which results in spontaneous Ca²⁺ efflux through the RyR2 Ca²⁺ release channel.^7,8 In turn, this store overload-induced calcium release (SOICR) through a defective RyR2^7–14 triggers delayed afterdepolarizations (DADs),^15–21 which have been implicated in catecholaminergic polymorphic ventricular tachycardias (CPVTs), as well as in ventricular tachyarrhythmias and sudden death.^4,5,22,23

The nonselective β-blocker carvedilol (1) and certain congeners also inhibit the α-adrenergic receptor²⁴ and are reported to display antioxidant activity.^25,26 Thus, 1 has proven uniquely effective in suppressing ventricular arrhythmias in patients with failing hearts.^27–30 Unfortunately, the benefits of carvedilol therapy are limited by drug intolerance and excessive β-blockade, with attendant complications of bradycardia and hypotension.^2,31 More recently, we demonstrated that a variety of other α- and β-blockers, as well as antioxidants, failed in the suppression of SOICR.³² This suggests that the unique efficacy of carvedilol in suppressing SOICR occurs independently of its α- and β-blocking activity and its antioxidant properties, and is instead principally due to its ability to stabilize Ca²⁺ handling via the RyR2 channel. Indeed, we recently reported three novel carvedilol analogs 2–4 with comparable abilities to inhibit SOICR to that of the parent compound 1 (ca. 10 μmolar), but with strongly attenuated β-blockade (ca. μmolar compared to nanomolar for 1). Compounds 2–4 proved highly effective in preventing stress-induced ventricular arrhythmias in mice (vide infra), without the undesired effects of excessive β-blockade.³²

For the purpose of these studies, a convenient single cell bioassay was developed for measuring SOICR suppression by drug candidates, based on human embryonic kidney (HEK 293) cells expressing a mutant RyR2 channel (R4496C).^7,8 This mutation results in spontaneous calcium release from the endoplasmic reticulum of the cells through the defective channel, with calcium efflux detected by the measurement of fluorescence from the Ca²⁺-sensitive indicator dye fura 2/AM (Invitrogen).

Moreover, the same R4496C mutation in mice renders them highly susceptible to stress-induced ventricular arrhythmias, which are easily triggered by stimulants such as caffeine and epinephrine. This provides a useful animal model for evaluating potential antiarrhythmic drugs.^9–14

Our initial efforts that led to the discovery of 2–4 were guided by the x-ray crystal structure of the complex of the carvedilol analog carazolol (5) with the β-adrenergic receptor that had been previously reported by Stevens, Kobilka and their coworkers.³³ Their results indicated that the carbazole amino group participates in hydrogen-bonding with residue S203 of the receptor, while multiple hydrogen bonds occur between the secondary alcohol and the protonated amino group of the β-amino alcohol moiety with residues D113, Y316 and N312. Furthermore, a series of hydrophobic interactions were observed involving the aromatic rings of the carbazole and the N-isopropyl group of 5 with corresponding hydrophobic pockets in the receptor. Blocking, modifying or relocating the key hydrogen bonding functionalities and hydrophobic regions of carvedilol might therefore be expected to disrupt its binding to the β-adrenergic receptor. Similarly, a catechol moiety is a common structural motif in many α-blockers,²⁴ suggesting that manipulation of this group in 1 could result in diminished α-blockade. However, such structural changes might also interfere with binding to RyR2 and SOICR suppression. We now report the synthesis of a wide range of novel structures, in addition to the carvedilol analogues 2–4, as part of a SAR investigation to determine how such structural modifications would affect the abilities of these compounds to decrease SOICR in the HEK 293 (R4496C) cell line.

Results

The SOICR-suppressing ability of a series of carvedilol analogs 2–94, 97 and 98, as well as of reference compounds 1, 95, 96 and 99–102 that were included for comparison, is shown in Tables 1–8. All compounds were tested for SOICR inhibition in the RyR2-R4496C mutant HEK293 cell line and the IC₅₀ values, along with the number of replicates and the total number of cells employed in the assay, are provided in the Tables.

Table 1.

SOICR inhibition by modified catechol analogs of 1.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	carvedilol 1		15.9 ± 2.5	6	375
2	6		11.2 ± 1.2	3	149
3	7		28.0 ± 0.6	3	191
4	8		16.8. ± 2.7	3	228
5	9		7.62 ± 0.44	3	159
6	10		15.1 ± 3.7	3	173
7	11		16.4 ± 4.2	3	235
8	12		11.6 ± 0.9	3	253
9	13		7.43 ± 0.65	3	202
10	14		8.52 ± 1.3	3	190
11	15		54.9 ± 5.7	3	255
12	16		35.2 ± 2.2	4	141

Table 8.

SOICR inhibition by other types of antiarrhythmic agents

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	metoprolol 95		>1000	3	185
3	96		>1000	3	146
4	97		69.8 ± 33	3	156
5	98		>1000	3	234
6	99		>1000	3	172
7	100		>1000	3	218
8	101		>1000	3	175
9	102		34.3 ± 6.7	4	187

Chemistry

The synthesis of compounds 1 and 6–8 and 10–16 in Table 1 was achieved by reacting the commercially available epoxide 103a with the corresponding amines 104a-l, as shown in Scheme 1. Cyclization of amino alcohols 1, 6, 7 and 16 with chloroacetyl chloride afforded lactams 17–20, while the use of 1,1′-carbonyldiimidazole afforded products 25–27 in Table 2. The reduction of 17–20 with lithium aluminum hydride provided 21–24. The free phenol 28 was obtained by demethylation of 25 with boron tribromide, while hydrolysis of 28 afforded the amino alcohol 9.

Scheme 1.

(a) LiBr, DME, 50 °C or i-PrOH, reflux. (b) chloroacetyl chloride, Et₃N, CHCl₃, room temp. (c) NaH, THF, room temp. (d) LiAlH₄, THF, room temp. (e) 1,1′-carbonyldiimidazole, Et₃N, CH₂Cl₂, room temp. (f) BBr₃, CH₂Cl₂, room temp. (g) 2M NaOH, EtOH, reflux.

Table 2.

SOICR inhibition by compounds with cyclized or alkylated linker chains.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	17		26.1 ± 3.6	14	410
2	18		>1000	3	206
3	19		>1000	3	197
4	20		52.9 ± 15	4	175
5	21		22.9 ± 2.7	3	133
6	22		86.7± 36	3	173
7	23		364 ± 91	3	234
8	24		>1000	3	248
9	25		86.3 ± 52	3	149
10	26		97.2 ± 63	2	186
11	27		113 ± 25	5	357
12	28		16.1 ± 7.2	3	191
13	29		18.3 ± 0.0	4	181
14	30		35.2 ± 5.2	3	139
15	31		11.7 ± 0.7	3	264

The methylated product 29 in Table 2 was prepared by methylation of 1 with iodomethane, while 30 was obtained from 1 by cyclization and N-methylation with dimethyl carbonate in one step, followed by hydrolysis (Scheme 2). Compound 31 was produced from the reaction of epoxide 103b with the N-methyl derivative of amine 104a, followed by O-methylation with iodomethane.

Scheme 2.

(a) NaH, MeI, THF, room temp. (b) (MeO)₂C=O, DABCO, DMF, 95 °C. (c) LiOH, EtOH, reflux. (d) i-PrOH, reflux. (e) NaH, MeI, DMF, room temp.

The products 2 and 33 in Table 3 were prepared from the reactions of amine 104a with the homologated epoxides 105 and 106, in turn obtained from 4-hydroxycarbazole and the corresponding homologated haloepoxides. Alternatively, 34 was produced from 4-hydroxycarbazole and amine 104a via the monotosylate 109. Compounds 36–38 were obtained from epoxide 103a and amines 110 and 111a,b, respectively, while the product 39, containing transposed alcohol and amine functionalities, was prepared from the carbazole derivative 112 and epoxide 113. These processes are summarized in Scheme 3. Cyclizations to afford lactams 32, 35 and 40 were effected from the corresponding amino alcohols 2, 34 and 39, respectively, with chloroacetyl chloride, as shown previously for 17–20 in Scheme 1.

Table 3.

Effects of homologation and transposition of linker chain on SOICR inhibition.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	2		16.8 ± 3.3	4	206
2	32		14.6 ± 3.5	3	177
3	33		11.4 ± 0.8	3	245
4	34		13.5 ± 2.3	3	163
5	35		86.7 ± 53	3	204
6	36		20.0 ± 1.6	3	167
7	37		10.2 ± 0.5	3	168
8	38		9.51 ± 2.3	3	217
9	39		24.4 ± 3.1	4	365
10	40		26.7 ± 3.2	7	381

Scheme 3.

(a) LiBr, DME, 60 °C. (b) K₂CO₃, DMF, 100 °C. (c) TBAF, THF, room temp. (d) TsCl, Et₃N, CHCl₃, 0 °C. (e) 104a, LiBr, DME, reflux. (f) i-PrOH, reflux. (g) LiBr, DME, reflux.

While the products in Tables 1–3 originated from 4-hydroxycarbazole, the syntheses of those in Table 4 were carried out similarly, but employing 3-hydroxycarbazole, its 6-fluoro derivative or 3-aminocarbazole instead, as shown in Scheme 4. Compound 46 was obtained by alkylation of amine 104a with bromide 115, which was obtained as a byproduct in the preparation of epoxide 114b. Similarily, compound 48 was obtained by alkylation of 104a with chloride 116, in turn obtained from 9-t-Boc-protected 3-aminocarbazole and epichlorohydrin. Furthermore, the products in Table 5 were obtained by analogous methods, employing 2-hydroxycarbazole, its 6-fluoro or 6,8-difluoro analogs, or 1-hydroxycarbazole as starting materials (Scheme 5). Lactams 41, 49 and 51 were again obtained by cyclization of the corresponding amino alcohols 3, 4 and 50, respectively, with chloroacetyl chloride, while cyclizations to afford 42 and 52 from 3 and 50, respectively, were effected with bromomethanesulfonyl chloride or 1,1′-carbonyldiimidazole.

Table 4.

SOICR inhibition by 3-carbazolyl analogs.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	3		7.74 ± 1.1	7	367
2	41		6.20 ± 1.8	3	167
3	42		436 ± 330	3	150
4	43		9.72 ± 3.1	3	214
5	44		4.66 ± 0.13	3	164
6	45		15.9 ± 5.1	3	252
7	46		9.74 ± 2.8	3	185
8	47		6.26 ± 2.8	3	166
9	48		16.6 ± 4.3	3	235

Scheme 4.

(a) 1 M NaOH, DMSO, room temp. or 40 °C. (b) 104a, i-PrOH, reflux. (c) 104a, Et₃N, MeOH, 60 °C. (d) EtOH, reflux. (e) 104a, K₂CO₂, cat. KI, EtOH, reflux. (f) TFA, CH₂Cl₂, room temp.

Table 5.

SOICR inhibition by 2- and 1-carbazolyl analogs.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	4		17.8 ± 3.6	5	174
2	49		19.8 ± 1.6	3	191
3	50		14.6 ± 2.4	3	275
4	51		>1000	3	279
5	52		354 ± 101	3	247
6	53		5.50 ± 2.3	3	206
7	54		4.37 ± 0.49	3	180
8	55		10.2 ± 0.9	3	165
9	56		15.4 ± 4.6	3	212
10	57		20.1 ± 4.5	2	229
11	58		12.4 ± 1.3	3	139

Scheme 5.

(a) 1 M NaOH, DMSO, room temp. or 40 °C. (b) i-PrOH, reflux.

The N-acylated carbazole derivatives 59 and 60 in Table 6 were prepared as shown in Scheme 6. While 60 was prepared by direct acylation of 17, compound 59 was more easily obtained by prior acylation of epoxide 103a, followed by ring-opening with amine 104a in the usual manner. The other compounds in Table 6 were prepared by alkylating the other indicated phenols or alcohols instead of 4-hydroxycarbazole with the corresponding haloalkyl epoxides, followed by treatment with amine 104a, as indicated in Scheme 6. Product 62 was obtained by Wolff-Kishner reduction of ketone 63, while desulfurization of 66 with nickel boride³⁴ afforded 65.

Table 6.

Effect of carbazole modification or replacement on SOICR inhibition.

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	59		>1000	3	180
2	60		86.5 ± 20	6	327
3	61		17.4 ± 1.1	3	261
4	62		17.0 ± 1.6	8	430
5	63		30.1 ± 2.6	17	982
6	64		11.0 ± 1.6	3	187
7	65		18.2 ± 2.7	5	392
8	66		5.7 ± 2.7	4	245
9	67		65.8 ± 6.5	3	140
10	68		15.1 ± 1.2	11	450
11	69		9.77 ± 2.0	3	188
12	70		75.6 ± 20	8	467
13	71		29.7 ± 11	2	206
14	72		28.0 ± 3.1	3	142
15	73		>1000	3	142
16	74		463 ± 129	3	185
17	75		>1000	3	167
18	76		213 ± 29	3	159
19	77		101 ± 16	3	189
20	78		>1000	3	179
21	79		545 ± 213	3	229
22	80		>1000	3	191

Scheme 6.

(a) NaH, THF, 0 °C. (b) 104a, LiBr, DME, 60 °C or i-PrOH, reflux. (c) 1 M NaOH, DMSO, 40 °C. (d) NH₂NH_2·H₂O, KOH, ethylene glycol, 100–160 °C. (e) NiCl₂·6H₂O, NaBH₄ (Ni₂B), MeOH-THF-H₂O, room temp.

The products 83–90 and 92 in Table 7 were obtained by treating epoxides 103a (entries 3, 4, 9, 10 and 12), 105 (entry 5), 114a (entry 6), 117a (entry 7) or 117c (entry 8) with the corresponding amines 104a or 118a-f, as shown in Scheme 7. The benzofuran and benzoxazole derivatives 81 and 82 (entries 1 and 2) were produced by reductive amination or alkylation of amine 119 with aldehyde 121 or chloride 122, respectively, followed by debenzylation of the intermediate benzylamines. Amides 93 and 94 (entries 13 and 14) were formed by amidation of carboxylic acid 120 with amines 104a or 118f, respectively, using N-(3-diethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC hydrochloride) and 1-hydroxybenzotriazole hydrate (HOBT·H₂O) as coupling reagents.³⁵ Product 91 (entry 11) was prepared by cyclization of 94 with diethylaminosulfur trifluoride (DAST).³⁶

Table 7.

Other modified carvedilol derivatives as SOICR inhibitors

entry	compound	structure	IC50 (μM) ± SEM	repeats (n)	no. of cells
1	81		>1000	3	193
2	82		>1000	3	234
3	83		5.76 ± 1.3	4	299
4	84		15.8 ± 5.0	3	171
5	85		19.7 ± 9.0	3	188
6	86		8.61 ± 0.47	3	218
7	87		>1000	3	153
8	88		>1000	3	191
9	89		34.9 ± 3.7	3	148
10	90		62.7 ± 15	4	201
11	91		19.8 ± 1.7	3	187
12	92		94.5 ± 60	3	216
13	93		3.55 ± 0.30	3	158
14	94		3.63 ± 0.18	3	127

Scheme 7.

(a) i-PrOH, reflux. (b) BnNH₂, i-PrOH, reflux. (c) 121, NaBH(OAc)₃, 1,2-dichloroethane or 122, DIPEA, cat. KI, MeCN, 60 °C. (d) H₂, 10% Pd/C, MeOH. (e) ethyl bromoacetate, NaOH, DMF, room temp. (f) KOH, MeOH-H₂O. (g) 104a or 118f, EDC·HCl, HOBT·H₂O, Et₃N, THF, room temp. (h) DAST, CH₂Cl₂-THF, −78 °C, 1 h; then K₂CO₃, room temp., 2 h.

Metoprolol (95) was obtained from commercial sources, while 4,6-dibromo-3-hydroxycarbazole (96) was prepared by a literature procedure.³⁷ The conversion of 96 to 97 and its further transformation to 98 was achieved via the same procedure that was employed for the preparation of 1 from 4-hydroxycarbazole, and for the cyclization of 1 to 17, as shown in Scheme 1. Products 99 and its hydrochloride salt 100,³⁸ as well as 102³⁹ were obtained by known procedures. Alternatively, the regioisomer 101 of 99 was prepared, along with 101, from the known thiapyrone 123,⁴⁰ as shown in Scheme 8.

Scheme 8.

(a) Borax, H₂O, room temp. (b) MeOH, 2 M NaOH, room temp. (c) TFA, TFAA, 60 ° C. (d) TMSN₃, TFA, room temp. (e) LiAlH₄, THF-Et₂O, reflux. (f) Formaldehyde, NaBH₃CN, MeOH, room temp.

SOICR Inhibition

The benchmark compound 1 displayed an IC₅₀ of 15.9 μM (Table 1, entry 1) in this assay. We first prepared and assayed several derivatives (6–16) with modified catechol groups, as shown in Table 1. Aromatic hydroxylation of the catechol moiety of carvedilol at the 4′- and 5′-positions is known to afford phenolic metabolites.⁴¹ Modification of these sites to probe their effect on SOICR inhibition was therefore of particular interest (entries 2–4). The introduction of 4′- and 5′-chloro substituents in 6 slightly improved SOICR activity, but replacement of the methoxy group with a third chlorine atom in 7 diminished the potency significantly. Surprisingly, the simple phenyl derivative 8 proved comparable to 1, while replacement of the methoxy substituent of 1 with a hydroxyl group in derivative 9 lowered the IC₅₀ by half. The similar replacement by methyl or methylthio groups (10 and 11, respectively) had no effect on activity. When the other catechol oxygen atom was replaced with sulfur or a methylene group (12 and 13, respectively), or when the methoxy group was also absent, as in 14, slightly higher activity compared to 1 was observed. On the other hand, replacement of the catechol moiety by a 2-pyridyl group (15) or by a cyclohexyl substituent (16) resulted in a three-fold and two-fold loss of activity, respectively.

We also investigated whether SOICR inhibition would be affected by manipulation of the β-amino alcohol moiety in the linker chain, which plays a critical role in the excessive β-blockade encountered with carvedilol. Entries 1–12 in Table 2 show the IC₅₀ values for analogs where this functionality was incorporated into various rings, with or without the previous modifications to the catechol region of the carvedilol molecule given in Table 1. In the case of δ-lactams 17–20, there was a moderate loss of activity compared to 1 when either the intact catechol moiety was retained (17), or when it was replaced by a simple cyclohexyl group (20). Moreover, the chlorinated derivatives 18 and 19 were essentially devoid of activity when introduced together with lactamization (cf. the relatively active chlorinated compounds 6 and 7 in Table 1). The morpholine analogs 21–24 revealed no consistent pattern of behavior when compared with the corresponding free β-amino alcohols 1, 6, 7 and 16, and with the corresponding lactams 17–20, respectively. While a slight decrease in activity was observed in 17 and 21 compared to 1, the chlorinated analogs 22 and 23 were intermediate between the corresponding amino alcohols 6 and 7 and the inactive lactams 18 and 19. The cyclohexyl derivative 24 was devoid of activity, in contrast to the weakly active amino alcohol 16. The cyclic carbamates 25–27 all showed poor SOICR inhibition compared to the corresponding amino alcohols 1, 6 and 16, while the free phenol analog 28 was comparable to carvedilol, but less active than the phenol 9 in this regard. Furthermore, alkylation of the aliphatic secondary amino group in 29 had little effect, while alkylation of the carbazole nitrogen in 30 resulted in diminished activity. Surprisingly, exhaustive alkylation of both nitrogens and of the secondary alcohol group in 31 produced a more strongly SOICR-inhibiting compound than either 1, 29 or 30.

Attempts to determine the effects of homologation of the linker chain at various sites upon SOICR inhibition were also made (Table 3, entries 1–8). Homologation was effected by insertion of one or more extra methylene units between the carbazole ether and secondary alcohol of 1 to afford 2, its cyclized derivative 32, and 33, respectively. Similarly, homologation between the alcohol and amino group provided 34 and the corresponding lactam 35, while insertion of an extra methylene unit between the amino group and the catechol ether and between the catechol ether and aromatic ring afforded derivatives 36 and 37, respectively. Products 2, 32, 33, 34, 37 and 38 proved comparable to 1, while 36 was slightly less potent. When homologation was combined with lactamization of the linker chain of 34 to afford 35, activity diminished more than 6-fold. Removal of the methoxy group from homologue 37 to give 38 had essentially no effect on the activity. Transposition of the alcohol and secondary amino groups in the linker chain of 1 and 17 was also investigated (entries 9 and 10). Thus, 39 and its lactam analog 40 were prepared and found to have IC50s ca. 1.7 times those of 1.

When the point of attachment of the linker was moved from the 4-position of the carbazole moiety (as in carvedilol) to the 3-position, a series of highly active compounds was obtained (Table 4, entries 1–7). Thus, compounds 3, 41, 43 and 44 all proved superior to carvedilol in their inhibition of SOICR. Cyclization of 3 to afford lactam 41 retained the high activity of the parent amino alcohol and only the sultam moiety of derivative 42 strongly impeded SOICR inhibition. Furthermore, homologation of 3 by one, two or three methylene units between the carbazole and hydroxyl functions produced the highly active analogs 43–45, respectively, with the lowest IC₅₀ of 4.66 μmol observed for the doubly homologated derivative 44. Single homologation between the alcohol and amino functions in 46 also produced a more potent product than carvedilol, while the 6-fluoro derivative 47 showed essentially identical activity to that of the parent compound 3 of this series. Replacement of the ether oxygen with an amino group at C-3 of the carbazole moiety in 48 resulted in comparable activity to that of carvedilol.

The 2-substituted carbazole series (Table 5, entries 1–10) was also investigated and revealed several highly active SOICR inhibitors. The parent compound 4, as well as its lactam and homologated counterparts 49 and 50, respectively, proved similar to carvedilol. In contrast, the homologated lactam 51 and cyclic carbamate 52 were ineffective in SOICR inhibition. Monofluorination of the 6- position or 6,8-difluorination of the carbazole had a beneficial effect on activity, leading to the highly potent analogs 53 and 54. Fluorination of the catechol moiety in compound 55, or fluoro or trifluoromethyl substitution of the methoxy group in 57 and 56, respectively, had little effect compared to 1 or 4. Finally, attachment of the linker chain to the 1-position of the carbazole unit in 58 (entry 11) also had little effect upon activity.

It has been suggested that the carbazole moiety of carvedilol serves to embed the molecule in the lipid bilayer of cell membranes.⁴² Furthermore, it provides a hydrophobic region and a hydrogen-bonding functionality that are key for binding to the β-adrenergic receptor.³³ In order to determine whether these structural features are also required for SOICR inhibition, we prepared a variety of analogs containing modified carbazole units (Table 6). In entries 1 and 2, amidation of the carbazole nitrogens of 1 and 17 with octadecanoic acid afforded 59 and the lactam derivative 60, respectively. Unlike the N-methylated derivatives 30 and 31 in Table 2, which showed comparable activity to carvedilol (1), amides 59 and 60 unfortunately revealed negligible or significantly diminished activity relative to 1 and 17.

Other carbazole modifications are shown in entries 3–22 of Table 6. The tetrahydrocarbazole 61, the fluorene and fluorenone analogs 62 and 63, respectively, that lack the carbazole nitrogen atom, as well as the diphenylamine 65, all showed comparable or only slightly lower activity than carvedilol. On the other hand, the dibenzofuran 64 and the phenothiazine 66 were more strongly active than 1, while oxidation of 66 to the corresponding sulfone 67 decreased activity by more than 10-fold. Replacement of the carbazole with naphthyl residues in 68 and its homologated analog 69 afforded potent SOICR inhibitors. The adamantyl residues in 70–72 resulted in less efficacious compounds and the quinolinone 73 and partially reduced quinolinones 74 and 75 were essentially inactive. The installation of indole (compounds 76 and 77), benzodiazole (compounds 78 and 79) and benzimidazole (compound 80) residues in place of the carbazole also produced very weak or essentially inactive products.

We also introduced additional heterocyclic groups into the linker chain or in place of the catechol moiety (Table 7, entries 1–12), as well as amide instead of amino alcohol functionalities (entries 13–14). The benzofuran and benzoxazoles 81 and 82 were devoid of activity, but the benzomorpholine 83 proved more than twice as potent as carvedilol (1). The lactam derivative 84 and homologue 85 were comparable to 1. Repositioning the linker chain of 85 to the 3- and 2-position of the carbazole moiety resulted in strong and negligible activities in 86 and 87, respectively. Fluorination of the 6-position of 87 to afford 88 failed to improve the bioactivity. Piperazines 89 and 90, as well as dihydrooxazole 91 and diaryl ether 92 displayed weaker activity than 1. Surprisingly, replacement of the amino alcohol moiety of 1 with amide linkages in 93 and 94 afforded the most potent SOICR inhibitors of this investigation, with IC₅₀ values of ca. 3.6 μM compared with 15.9 μM for carvedilol.

Several other classes of compounds have been reported to provide salutary effects in the treatment of cardiac arrhythmias. We therefore measured their SOICR inhibiting properties in order to compare them with the above carvedilol analogs (Table 8). The clinically useful β-blocker metoprolol (95) was devoid of any SOICR-inhibition in the mutant HEK293 single cell bioassay. This result is consistent with our previous finding³² that carvedilol is unique in the family of β-blocker drugs in effectively suppressing SOICR in the HEK293 cell line and in the knock-in mouse model.

Furthermore, compound 96 has been reported to inhibit Ca²⁺-induced Ca²⁺ release (CICR) in skeletal muscle sarcoplasmic reticulum.³⁷ In the RyR2-R4496C mutant HEK293 cell assay it exhibited negligible activity, which improved substantially when its structure was incorporated into the novel carvedilol derivative 97, while further lactamization of the amino alcohol in 98 resulted in complete loss of activity. The thiazepine compounds 99³⁸ and 102³⁹ have been reported to suppress ventricular arrhythmias and sudden death in mice through enhanced binding of the 12.6 kDa FK506 binding protein (FKBP12.6) to the RyR2 channel. However, neither 99, its hydrochloride salt 100, nor its isomer 101 displayed any measurable activity in the present assay. On the other hand, the amide derivative 102 showed activity about one-half that of 1.

Discussion

These results demonstrate that considerable variation in the structure of carvedilol is possible while retaining strong SOICR-suppressing activity in the RyR2-R4496C mutant HEK293 single cell assay. Thus, 34 of the above compounds (3, 6, 9, 10, 12–14, 31–34, 37, 38, 41, 43–47, 50, 53–56, 58, 64, 66, 68, 69, 83, 84, 86, 93 and 94) proved equal or superior to carvedilol (1) in this assay. This subset of highly potent analogs reveals that significant changes can be tolerated in the catechol, linker and carbazole moieties without loss of activity relative to the clinically useful drug 1. All of the compounds in Table 1, where modifications to the catechol subunit are listed, show significant activity. Beneficial catechol modifications include chlorination of the 4′- and 5′-positions (compound 6), which is expected to block metabolic oxidation at those sites and possibly retard clearance. The 2′-methoxy group can be replaced by H, OH, Me or MeS substituents (compounds 8, 9, 10 and 11) and the 1′-ether oxygen can be replaced by S (compound 12) or CH₂ (compounds 13 and 14) without deleterious effects on SOICR inhibition. Remarkably, the simple phenyl derivative 14 is roughly twice as potent as 1, while even the pyridyl and cyclohexyl analogs 15 and 16 show only a three- or two-fold loss of activity. This suggests that the compounds in Table 1 may prove good candidates as SOICR inhibitors.

The β-amino alcohol functionality plays a key role in mediating β-adrenergic blockade via multiple hydrogen-bonding interactions with the β-receptor.³³ In order to determine whether or not this functionality plays a similar role in SOICR inhibition, we investigated the alkylation of these key groups via incorporation into cyclic structures or by simple methylation. However, Table 2 indicates mixed results with respect to the SOICR inhibition shown by such compounds. While the lactam and morpholine derivatives of carvedilol (17 and 21, respectively), as well as the O- and N-methylated compounds 29–31 showed similar or slightly lower SOICR inhibition compared to 1, further alteration of these structures was generally accompanied by severe or total loss of activity.

The variously homologated analogs in Table 3 (2, 32–34 and 36–38) and the compounds with transposed amino alcohol linkers (39 and 40) all showed strong SOICR suppression in the mutant HEK293 cells. Similarly, relocation of the point of attachment of the linker chain from the 4-position (as in 1) to the 3-, 2- or 1-positions of the carbazole subunit generally had a salutary effect on the compounds in Tables 4 and 5, except for the sultam derivative 42, the lactam 51 and the cyclic carbamate 52.

The alterations to the carbazole moiety shown in Table 6 produced mixed results. The relatively strong activity of several analogs lacking the carbazole nitrogen or other hydrogen-bonding functionalities is noteworthy. Thus, the fluorenyl derivative 62, naphthyl derivatives 68 and 69, and the weaker but still significantly active adamantyl analogs 70–72 demonstrate that the hydrogen-bonding carbazole NH functionality that participates in binding to the β-receptor is not required for SOICR inhibition. However, N-acylation of the carbazole nitrogen suppressed activity (compounds 59 and 60), while other heterocyclic groups displayed IC₅₀s ranging from 5.7 μM (compound 66) to complete loss of activity. The more extensive structural modifications to the compounds listed in Table 7 also had varied effects on SOICR suppression. Of special interest are the benzomorpholine derivative 83 and the amides 93 and 94, with IC₅₀s ranging from 3.55 to 5.76 μM, compared to 15.9 μM for 1.

Finally, we note the striking contrast between the most active SOICR inhibitors described above and the SOICR-suppressing abilities of several conventional β-blockers and antiarrhythmic agents shown in Table 8. The complete absence of such activity in the case of metoprolol (95), the dibromocarbazole derivatives 96 and 98, and the thiazepine derivatives 99–101 strongly suggest that the latter compounds express their antiarrhythmic effects through different mechanisms to the active compounds described in Tables 1–7. Only the carvedilol-resembling analog 97 and the thiazepine 102 exhibited any measurable effect on SOICR suppression.

Conclusions

It was recently demonstrated that the effectiveness of carvedilol as an antiarrhythmic therapy for patients with heart failure was due in part to its ability to suppress SOICR by regulating calcium efflux through the RyR2 channel.³² As a continuation of this investigation, we screened ca. 100 mostly novel compounds for their SOICR-suppressing effects on the RyR2-R4496C mutant HEK293 cell line. The wide variety of modifications that are tolerated suggests that RyR2 is a promiscuous channel that accommodates a broad range of ligands, including ones with structural changes to the carbazole, linker chain and catechol moieties of carvedilol.

Experimental Section

All compounds subjected to bioassay for which elemental analyses were not provided were of >95% purity as determined by HPLC analysis employing the following conditions: Novapak C₁₈ reversed-phase column, 3.9 × 150 mm; solvent: acetonitrile–water, 70:30, 0.8 mL/min; UV detector: 254 nm. ¹H NMR spectra were obtained at 300 or 400 MHz. ¹³C NMR spectra were obtained at 75 or 101 MHz. ¹⁹F NMR spectra were obtained at 376 MHz with hexafluorobenzene (-164 ppm) as the external standard, relative to trichlorofluoromethane (0.00 ppm). Products 2–4 were prepared as described previously in the Supporting Information of ref. 32.

Typical procedure for the preparation of compounds 6–16

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[2-(4,5-dichloro-2-methoxyphenoxy)ethyl]amino}-2-propanol (6)⁴³

Epoxide 103a (169 mg, 0.706 mmol) and amine 104b (250 mg, 1.06 mmol) were refluxed for 2 h in isopropanol (4 mL). The solvent was then removed under vacuum, the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to obtain 208 mg (62%) of product 6 as a white solid; mp 149–151 °C; IR (film): 3294, 1544, 1258, 1092 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.21 (d, J = 7.7 Hz, 1H), 8.06 (s, 1H), 7.46–7.14 (m, 4H), 7.06 (d, J = 7.7 Hz, 1H), 6.87 (s, 1H), 6.75 (s, 1H), 6.64 (d, J = 7.7 Hz, 1H), 4.29–3.91 (m, 5H), 3.57 (s, 3H), 3.30–3.12 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 155.2, 149.0, 147.5, 141.1, 138.8, 126.8, 125.2, 124.2, 123.5, 123.0, 122.6, 119.8, 115.3, 113.4, 112.8, 110.2, 104.0, 101.4, 70.4, 69.2, 68.5, 56.3, 52.1, 48.6; MS (ESI), m/z (relative intensity) 475 [M + 1]⁺. HRMS (EI) calcd for C₂₄H₂₄³⁵Cl₂N₂O₄ [M⁺]: 474.1113; found: 474.1123.

Compounds 7–8 and 10–16 were prepared similarly.

1-(9H-Carbazol-4-yloxy)-3-{[2-(2,4,5-trichlorophenoxy)ethyl]amino}-2-propanol (7)⁴³

Yield: 66%; white solid; mp 146–148 °C; IR (film): 3285, 1452, 1095 cm⁻; ¹H NMR (300 MHz, CDCl₃) δ 8.24 (d, J = 7.8 Hz, 1H), 8.07 (s, 1H), 7.44–7.35 (m, 3H), 7.32 (dd, J = 8.0, 8.1 Hz, 1H), 7.20 (ddd, J = 1.6, 6.7, 8.1 Hz, 1H), 7.06 (dd, J = 0.5, 8.1 Hz, 1H), 6.96 (s, 1H), 6.68 (d, J = 7.6 Hz, 1H), 4.38–4.24 (m, 3H), 4.15–4.07 (m, 2H), 3.20–3.11 (m, 3H), 3.06 (dd, J = 6.9, 12.2 Hz, 1H); ¹³C NMR (75 MHz, CDCl₃) δ 154.9, 153.2, 141.4, 139.1, 131.1, 130.7, 126.3, 124.6, 124.3, 122.5, 122.1, 118.8, 114.9, 112.3, 110.1, 104.1, 100.4, 70.1, 68.6, 68.4, 52.2, 48.0; MS (EI), m/z (relative intensity) 478 (4) [M⁺], 184 (14), 183 (100). HRMS (EI) calcd for C₂₃H₂₁³⁵Cl₃N₂O₃ [M]⁺: 478.0618; found: 478.0619.

1-(9H-Carbazol-4-yloxy)-3-[2-(phenoxyethyl)amino]-2-propanol (8)^44,45

Yield 76%; white solid; mp 109–111 °C; IR (film) 3407, 3244, 3055, 2924, 2873, 1597, 1506, 1453, 1242, 1095, 750, 725 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J = 7.8 Hz, 1H), 8.07 (br s, 1H), 7.19–7.44 (m, 6H), 7.07 (d, J = 7.7 Hz, 1H), 6.95 (dd, J = 10.5, 4.2 Hz, 1H), 6.90 (dd, J = 8.7, 1.0 Hz, 2H), 6.68 (d, J = 7.9 Hz, 1H), 4.38–4.20 (m, 3H), 4.12 (t, J = 5.2 Hz, 2H), 3.19–3.10 (m, 3H), 3.05 (dd, J = 12.3, 7.3 Hz, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 158.9, 155.3, 141.1, 138.9, 129.6, 126.8, 125.2, 123.1, 122.7, 121.1, 119.9, 114.7, 112.9, 110.2, 104.0, 101.5, 70.5, 68.7, 67.3, 52.1, 49.0; MS (ESI) m/z (relative intensity) 377 (100) [M+H]⁺; HRMS (ESI) calcd for C₂₃H₂₅N₂O₃ [M+H]⁺: 377.1860; found: 377.1856.

1-(9H-Carbazol-4-yloxy)-3-{[2-(2-methylphenoxy)ethyl]amino}-2-propanol (10)^44,45

Yield: 76%; white solid; mp 118–119 °C; IR (film) 3407, 3306, 3055, 2924, 1606, 1497, 1453, 1242, 1098, 750, 719 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 7.7 Hz, 1H,), 8.07 (br s, 1H), 7.36–7.44 (m, 2H), 7.32 (dd, J = 8.0, 7.9 Hz, 1H), 7.21 (ddd, J = 8.1, 6.5, 1.8 Hz, 1H), 7.04–7.17 (m, 3H), 6.91–6.79 (m, 2H), 6.68 (d, J = 7.9 Hz, 1H,), 4.40–4.20 (m, 3H), 4.12 (t, J = 5.1 Hz, 2H,), 3.22–3.12 (m, 3H), 3.06 (dd, J = 12.3, 7.1 Hz, 1H), 2.20 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 156.9, 155.2, 141.1, 138.8, 130.8, 127.0, 126.9, 126.8, 125.1, 123.0, 122.6, 120.7, 119.8, 112.9, 111.3, 110.1, 104.0, 101.4, 70.5, 68.6, 67.4, 52.0, 49.0, 16.3; MS (ESI) m/z (relative intensity) 391 (100) [M+H]⁺. HRMS (ESI) calcd for C₂₄H₂₇N₂O₃ [M+H]⁺: 391.2012; found: 391.2016.

1-(9H-Carbazol-4-yloxy)-3-{[2-(2-methylthiophenoxy)ethyl]amino}-2-propanol 11⁴⁵

Yield 65%; white solid; mp 103–104 °C; IR (film) 3407, 3297, 2917, 1606, 1456, 1435, 1236, 1095, 756, 722 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J = 7.8 Hz, 1H), 8.08 (br s, 1H), 7.35–7.46 (m, 2H), 7.32 (dd, J = 8.0, 8.0 Hz, 1H), 7.21 (ddd, J = 8.0, 6.7, 1.6 Hz, 1H), 7.08–7.15 (m, 2H), 7.06 (d, J = 8.0 Hz, 1H,), 6.97 (ddd, J = 7.6, 7.4, 1.2 Hz, 1H,), 6.81–6.88 (m, 1H), 6.69 (d, J = 7.9 Hz, 1H), 4.15–4.39 (m, 5H), 3.14–3.22 (m, 3H), 3.06 (dd, J = 12.3, 7.0 Hz, 1H), 2.36 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 155.3 (C), 155.2 (C), 141.1 (C), 138.8 (C), 127.9 (C), 126.7 (CH), 125.8 (2 x CH), 125.1 (CH), 123.0 (CH), 122.6 (C), 121.8 (CH), 119.8 (CH), 112.9 (C), 112.0 (CH), 110.1 (CH), 103.9 (CH), 101.4 (CH), 70.3 (CH₂), 68.6 (CH), 68.4 (CH₂), 51.9 (CH₂), 48.7 (CH₂), 14.5 (CH₃); MS (EI) m/z (relative intensity) 422 (20) [M⁺], 196 (66), 182 (100), 153 (38). HRMS (EI) calcd for C₂₄H₂₆N₂O₃S [M]⁺: 422.1664; found: 422.1676.

1-(9H-Carbazol-4-yloxy)-3-{[2-[(2-methoxyphenylthio)ethyl]amino}-2-propanol (12)⁴⁵

Yield 69%; white solid; mp 48–49 °C; IR (film) 3407, 2930, 2833, 1603, 1581, 1456, 1098, 910, 750, 725 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.25 (d, J = 7.8 Hz, 1H), 8.08 (s, 1H), 7.47 – 7.29 (m, 4H), 7.26 – 7.18 (m, 2H), 7.06 (d, J = 8.0 Hz, 1H), 6.90 (td, J = 7.5, 1.1 Hz, 1H), 6.86 (d, J = 8.2 Hz, 1H), 6.68 (d, J = 7.9 Hz, 1H), 4.40–4.15 (m, 3H), 3.88 (s, 3H), 3.14–3.01 (m, 3H), 2.99–2.85 (m, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 158.1, 155.1, 141.0, 138.8, 131.3, 128.1, 126.7, 125.1, 123.2, 123.0, 122.6, 121.2, 119.8, 112.8, 110.8, 110.1, 104.0, 101.3, 70.3, 68.5, 55.9, 51.7, 48.2, 33.0; MS (EI) m/z (relative intensity) 422 (45) [M⁺], 269 (100), 195 (50), 182 (68), 153 (52), 120 (50). HRMS (EI) calcd for C₂₄H₂₆N₂O₃S [M]⁺: 422.1664; found: 422.1658.,

1-(9H-Carbazol-4-yloxy)-3-{[3-(2-methoxyphenyl)propyl]amino}-2-propanol (13)⁴⁵

Yield: 64%; white solid; mp 104–105 °C; IR (film) 3407, 2933, 2836, 1603, 1503, 1456, 1239, 1098, 907, 750, 719 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 7.8 Hz, 1H), 8.09 (s, 1H), 7.47–7.35 (m, 2H), 7.32 (t, J = 8.0 Hz, 1H), 7.22 (ddd, J = 8.0, 6.6, 1.6 Hz, 1H), 7.17 (td, J = 8.0, 1.7 Hz, 1H), 7.12 (dd, J = 7.3, 1.5 Hz, 1H), 7.06 (d, J = 8.0 Hz, 1H), 6.88 (td, J = 7.4, 1.0 Hz, 1H), 6.84 (d, J = 8.1 Hz, 1H), 6.67 (d, J = 7.9 Hz, 1H), 4.47–4.09 (m, 3H), 3.80 (s, 3H), 3.06 (dd, J = 12.2, 3.5 Hz, 1H), 2.96 (dd, J = 12.2, 7.6 Hz, 1H), 2.86–2.61 (m, 4H), 1.81–1.91 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 157.6, 155.3, 141.1, 138.9, 130.4, 130.0, 127.2, 126.8, 125.1, 123.0, 122.7, 120.6, 119.8, 112.9, 110.4, 110.1, 104.0, 101.4, 70.6, 68.4, 55.4, 52.1, 49.5, 30.2, 27.8; MS (EI) m/z (rel intensity) 404 (40), 182 (100), 178 (88), 153 (50); HRMS (EI+) m/z calcd for C₂₅H₂₈N₂O₃ [M]⁺: 404.2100. Found: 404.2101.

1-(9H-Carbazol-4-yloxy)-3-[3-(phenylpropyl)amino]-2-propanol (14)⁴⁵

Yield: 64%; white solid; mp 110–111 °C; IR (film) 3407, 3084, 2917, 1603, 1450, 1095, 756, 716 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 7.8 Hz, 1H), 8.08 (s, 1H), 7.48–7.36 (m, 2H), 7.32 (dd, J = 8.0, 8.0 Hz, 1H), 7.29–7.13 (m, 6H), 7.06 (d, J = 7.9 Hz, 1H), 6.67 (d, J = 7.9 Hz, 1H), 4.36–4.17 (m, 3H), 3.04 (dd, J = 12.2, 3.5 Hz, 1H), 3.00–2.89 (m, 1H), 2.85–2.61 (m, 4H), 1.87 (p, J = 7.2 Hz, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 155.2, 142.1, 141.1, 138.9, 128.5 (2C), 126.8, 125.9, 125.1, 123.0, 122.6, 119.8, 112.8, 110.2, 104.0, 101.4, 70.5, 68.5, 52.2, 49.5, 33.6, 31.7; MS (EI) m/z (relative intensity) 374 (18) [M⁺], 183 (100). HRMS (EI) calcd for C₂₄H₂₆N₂O₂ [M]⁺: 374.1994; found: 374.1994.

1-(9H-Carbazol-4-yloxy)-3-{2-(2-pyridyloxy)ethyl]amino}-2-propanol (15)

Yield 54%; white solid; mp 122–123 °C; IR (film) 3396, 3291, 2916, 1589, 1432, 1286, 1094, 783, 751, 720 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 8.0 Hz, 1H), 8.14 (ddd, J = 5.0, 2.0, 0.8 Hz, 1H), 8.08 (s, 1H), 7.55 (ddd, J = 8.3, 7.1, 2.0 Hz, 1H), 7.34–7.43 (m, 2H), 7.32 (dd, J = 8.0, 8.0 Hz, 1H), 7.21 (ddd, J = 8.1, 6.8, 1.4 Hz, 1H), 7.06 (dd, J = 8.1, 0.5 Hz, 1H), 6.86 (ddd, J = 7.1, 5.1, 0.9 Hz, 1H), 6.72 (dt, J = 8.4, 0.9 Hz, 1H), 6.68 (d, J = 8.0 Hz, 1H), 4.43–4.52 (m, 2H), 4.20–4.38 (m, 3H), 2.98–3.25 (m, 5H); ¹³C NMR (101 MHz, CDCl₃) δ 163.8, 155.2, 146.9, 141.1, 138.8, 138.8, 126.8, 125.2, 123.1, 122.6, 119.9, 117.1, 112.9, 111.2, 110.1, 104.0, 101.4, 70.4, 68.5, 65.3, 52.1, 49.0; MS (ESI) m/z (relative intensity) 378 (100) [M+H]⁺. HRMS (EI) calcd for C₂₂H₂₃N₃O₃ [M]⁺: 377.1739; found: 377.1742.

1-(9H-Carbazol-4-yloxy)-3-{2-[(cyclohexyloxy)ethyl]amino}-2-propanol (16)⁴³

Yield: 68%; viscous oil; IR (neat) 3401, 3280, 3051, 1450, 1094 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.28 (d, J = 7.7 Hz, 1H), 8.14 (s, 1H), 7.41–7.22 (m, 4H), 7.06 (d, J = 7.7 Hz, 1H), 6.68 (d, J = 7.7 Hz, 1H), 4.32–4.22 (m, 3H), 3.62–3.59 (m, 2H), 3.27–3.24 (m, 1H), 3.12–3.07 (m, 1H), 3.01- 2.78 (m, 4H), 2.00–1.89 (m, 2H), 1.72–1.71 (m, 2H), 1.54–1.49 (m, 1H), 1.39–1.19 (m, 5H); ¹³C NMR (75 MHz, CDCl₃) δ 155.2, 141.1, 138.9, 126.8, 125.1, 123.1, 122.7, 119.8, 112.83, 110.2, 104.0, 101.4, 78.1, 70.4, 68.3, 66.6, 52.1, 49.6, 32.4, 25.9, 24.3; MS (EI), m/z (relative intensity) 382 (4) %) [M⁺], 269 (18), 183 (100). HRMS (EI) calcd for C₂₃H₃₀N₂O₃ [M]⁺: 382.2256; found: 382.2270.

Typical procedure for the preparation of compounds 17–20

Preparation of 6-[(9H-carbazol-4-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]-3-morpholinone (17)⁴³

Chloroacetyl chloride (113 mg, 1.00 mmol) was added to an ice-cooled solution of carvedilol (1) (406 mg, 1.00 mmol) and triethylamine (152 mg, 1.50 mmol) in chloroform. The reaction mixture was warmed to room temperature and stirred for 6 h. It was then quenched with water (10 mL) and extracted with chloroform. The combined organic layers were washed with saturated NH₄Cl solution (25 mL), dried over Na₂SO₄ and evaporated under reduced pressure. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford the corresponding chloroacetyl derivative. A suspension of NaH (1.1 mmol) in anhydrous THF was cooled to 0° C. The above product was dissolved in THF and was added to the NaH mixture. The reaction mixture was stirred for 12 h at room temperature, quenched cautiously with water (10 mL) and extracted with ethyl acetate. The combined organic layers were washed with sat. NH₄Cl solution, dried over Na₂SO₄ and evaporated under reduced pressure. Flash chromatography of the residue over silica gel column afforded 321 mg (72%) of 17 as a viscous oil; IR (neat): 3270, 1652, 1504, 1252 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.28–8.19 (m, 2H), 7.44–7.06 (m, 6H), 7.01–6.81 (m, 3H), 6.65 (d, J = 7.7 Hz, 1H), 4.45–4.21 (m, 7H), 3.96–3.79 (m, 4H), 3.69 (s, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 167.1, 154.9, 149.8, 148.1, 141.2, 138.9, 126.7, 125.3, 123.1, 122.5, 122.0, 121.0, 119.9, 114.1, 113.0, 112.0, 110.2, 104.4, 101.3, 72.2, 68.4, 68.0, 67.9, 55.8, 51.3, 47.1; MS (EI), m/z (relative intensity) 446 (17) [M⁺], 323 (100). HRMS calcd for C₂₆H₂₆N₂O₅ [M⁺]: 446.1842; found 446.1844.

Compounds 18–20 were prepared similarly from the corresponding amino alcohols.

6-[(9H-Carbazol-4-yloxy)methyl]-4-[2-(4,5-dichloro-2-methoxyphenoxy)ethyl]-3-morpholinone (18)⁴³

Yield: 92%; viscous oil; IR (neat) 3275, 1650 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.20 (d, J = 7.7 Hz, 1H), 8.09 (s, 1H), 7.40–7.34 (m, 2H), 7.31 (t, J = 8.0 Hz, 1H), 7.12 (dd, J = 7.9, 4.5 Hz, 1H), 7.05 (d, J = 8.1 Hz, 1H), 6.92 (s, 1H), 6.78 (s, 1H), 6.66 (d, J = 7.7 Hz, 1H), 4.48–4.18 (m, 7H), 4.01–3.78 (m, 4H), 3.57 (s, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 167.2, 154.8, 148.9, 147.3, 141.1, 138.8, 128.5, 126.7, 125.4, 123.5, 123.0, 122.4, 119.9, 115.2, 113.3, 112.9, 110.2, 104.4, 101.3, 72.1, 68.3, 68.2, 67.9, 56.1, 51.3, 46.8; MS (EI), m/z (relative intensity) 514 (6) [M⁺] 323 (100), 183 (18), 154 (48). HRMS calcd for C₂₆H₂₄35Cl₂N₂O₅ [M⁺]: 514.1062; found: 514.1067.

6-[(9H-Carbazol-4-yloxy)methyl]-4-[(2,4,5-trichlorophenoxy)ethyl]-3-morpholinone (19)⁴³

Yield: 77%; white solid; mp 106–108 °C; IR (film): 3268, 1652 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.22 (d, J = 7.7 Hz, 1H), 8.08 (s, 1H), 7.44–7.18 (m, 5H), 7.09 (d, J = 7.7 Hz, 1H), 6.96 (s, 1H), 6.67 (d, J = 7.7 Hz, 1H), 4.44–4.19 (m, 7H), 4.02–3.82 (m, 4H); ¹³C NMR (75 MHz, CDCl₃) δ 167.7, 154.5, 152.9, 141.3, 139.0, 131.3, 130.8, 126.3, 124.9, 124.6, 122.7, 122.1, 121.7, 119.2, 114.6, 112.5, 110.2, 104.4, 100.8, 71.9, 67.9, 67.8, 67.5, 51.0, 46.7; MS (EI), m/z (relative intensity) 518 (14) [M⁺], 323 (33), 183 (100). HRMS calcd for C₂₅H₂₁35Cl₃N₂O₄: 518.0567; found: 518.0599.

6-[(9H-Carbazol-4-yloxy)methyl]-4-[2-(cyclohexyloxy)ethyl]-3-morpholinone (20)⁴³

Yield: 41%; viscous oil; IR (neat) 3267, 1640; ¹H NMR (300 MHz CDCl₃) δ 8.24 (d, J = 7.7 Hz, 1H), 8.14 (s, 1H), 7.49–7.23 (m, 4H), 7.10 (d, J = 7.7 Hz, 1H), 6.68 (d, J = 7.7 Hz, 1H), 4.50–4.24 (m, 5H), 3.78 (d, J = 6.9 Hz, 2H), 3.66 (dd, J = 15.8, 4.6 Hz, 4H), 3.28–3.17 (m, 1H), 1.92–1.78 (m, 2H), 1.76–1.42 (m, 3H), 1.32–1.08 (m, 5H); ¹³C NMR (75 MHz, CDCl₃) δ 166.9, 154.8, 141.2, 139.0, 126.7, 125.3, 123.1, 122.5, 119.8, 112.9, 110.3, 104.5, 101.3, 72.1, 68.3, 67.9, 66.2, 51.1, 47.7, 32.3, 29.9, 25.8, 24.1; MS (EI), m/z (relative intensity) 422 (24) [M⁺], 296 (16), 183 (100). HRMS (EI) calcd for C₂₅H₃₀N₂O₄ [M⁺]: 422.2206; found: 422.2225.

Typical procedure for the preparation of compounds 21–24

Preparation of 4-{4-[2-(2-methoxyphenoxy)ethyl]-2-morpholinyl]methoxy}-9H-carbazole (21)⁴³

A solution of 17 (446 mg, 1.00 mmol) in THF was added to a suspension of LiAlH₄ (38 mg, 1.0 mmol) in THF and the mixture was stirred at room temperature for 3h. The reaction was quenched with ethyl acetate followed by saturated Na₂SO₄ solution. The crude mixture was filtered through Celite and the residue was washed with ethyl acetate. The filtrate was dried over Na₂SO₄, evaporated under reduced pressure and the residue was purified by flash chromatography over silica gel to afford 259 mg (60%) of 21 as a viscous oil; IR (neat) 3290 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.30 (d, J = 7.7 Hz, 1H), 8.09 (s, 1H), 7.46–7.17 (m, 4H), 7.06 (d, J = 7.7 Hz, 1H), 6.96–6.84 (m, 4H), 6.66 (d, J = 7.7 Hz, 1H), 4.40–4.05 (m, 5H), 4.04–3.93 (m, 1H), 3.91–3.76 (m, 1H), 3.78 (s, 3H), 3.34–3.22 (m, 1H), 3.04–2.84 (m, 3H), 2.58–2.31 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 155.3, 149.9, 148.4, 141.1, 138.9, 126.8, 125.1, 123.2, 122.7, 121.8, 121.1, 119.8, 114.2, 112.9, 112.2, 110.1, 104.0, 101.3, 74.2, 69.3, 67.0, 66.9, 57.7, 56.8, 56.0, 53.8; MS (EI), m/z (relative intensity) 432 (17) [M⁺], 295 (100). HRMS (EI) calcd for C₂₆H₂₈N₂O₄ [M⁺]: 432.2049; found: 432.2017.

Compounds 22–24 were prepared similarly.

4-{[4-[2-(4,5-Dichloro-2-methoxyphenoxy)ethyl]-2-morpholinyl]methoxy}-9H-carbazole (22)⁴³

Yield: 86%; viscous oil; IR (neat): 3280, 1600, 1503 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.29 (d, J = 7.7 Hz, 1H), 8.09 (s, 1H), 7.46–7.13 (m, 3H), 7.06 (d, J = 7.7 Hz, 1H), 6.98–6.80 (m, 3H), 6.67 (d, J = 7.7 Hz, 1H), 4.37–3.97 (m, 7H), 3.80 (s, 3H), 3.32–3.22 (m, 1H), 3.02–2.84 (m, 3H), 2.58–2.29 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 155.2, 149.9, 141.1, 138.9, 126.8, 125.1, 123.2, 122.7, 121.9,121.0, 120.5, 119.8, 114.5, 113.0, 112.7, 112.1, 110.1, 104.0, 101.4, 74.2, 69.2, 57.6, 56.1, 56.0, 53.8; MS (EI), m/z (relative intensity) 500 (10) [M⁺], 296 (20), 295 (100). HRMS (EI) calcd for C₂₆H₂₇35Cl₂N₂O₄ [M⁺]: 500.1270; found: 500.1263.

4-{[4-[2-(2,4,5-Trichlorophenoxy)ethyl]-2-morpholinyl]methoxy}-9H-carbazole (23)⁴³

Yield: 66%; viscous oil; IR (neat): 3308 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.25 (d, J = 7.7 Hz, 1H), 8.07 (s, 1H), 7.46–7.23, (m, 4H), 7.20–7.12 (m, 1H), 7.07 (d, J = 7.7 Hz, 1H), 7.00 (s, 1H), 6.67 (d, J = 7.7 Hz, 1H), 4.38–4.10 (m, 6H), 4.08–3.86 (m, 2H), 3.46–3.25 (m, 1H), 3.16–2.92 (m, 2H), 2.74–2.48 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 155.2, 153.3, 141.0, 138.8, 131.3, 131.0, 126.8, 125.2, 124.8, 123.1, 122.6, 122.3, 119.8, 115.1, 112.9, 110.1, 104.1, 101.4, 74.0, 69.1, 67.8, 66.8, 57.2, 56.6, 53.8; MS (EI), m/z (relative intensity) 504 (7) [M⁺], 295 (44), 43 (100). HRMS (EI) calcd for C₂₅H₂₃35Cl₃N₂O₃ [M⁺]: 504.0774; found: 504.0757.

4-{[4-[2-(Cyclohexyloxy)ethyl]-2-morpholinyl]methoxy}-9H-carbazole (24)⁴³

Yield: 60%; viscous oil; IR (neat) 3293, 1606, 1341, 1100 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.31 (d, J = 7.7 Hz, 1H), 8.11 (s, 1H),7.46–7.20 (m, 4H), 7.06 (d, J = 7.7 Hz, 1H), 6.66 (d, J = 7.7 Hz, 1H), 4.38–4.28 (m, 1H), 4.23–4.12 (m, 2H), 3.98 (d, J = 9.9 Hz, 1H), 3.84 (ddd, J = 11.3, 11.2, 2.3 Hz, 1H), 3.66 (t, J = 6.1 Hz, 2H), 3.28–3.17 (m, 2H), 2.85 (d, J = 11.6 Hz, 1H), 2.66 (t, J = 6.0 Hz, 2H), 2.37 (ddd, J = 11.4, 11.3, 3.3 Hz, 1H), 2.32–2.23 (m, 1H), 1.96–1.83 (m, 2H), 1.78–1.62 (m, 2H), 1.55–1.48 (m, 1H), 1.36–1.14 (m, 5H); ¹³C NMR (75 MHz, CDCl₃) δ 155.3, 141.1, 13.9, 126.8, 125.1, 123.3, 122.7, 119.8, 113.0, 110.1, 103.9, 101.3, 74.2, 69.4, 67.0, 65.5, 58.8, 56.9, 53.9, 32.4, 29.8, 25.9, 24.4; MS (EI), m/z (relative intensity) 408 (6) [M⁺], 295 (100). HRMS (EI) calcd for C₂₅H₃₂N₂O₃ [M⁺]: 408.2413; found: 408.2415.

Typical procedures for the preparation of compounds 25–27

Preparation of 5-[(9H-carbazol-4-yloxy)methyl]-3-[2-(2-methoxyphenoxy)ethyl]-2-oxazolidinone (25)^43,46,47

A solution of carvedilol 1 (99 mg, 0.24 mmol), triethylamine (51 μL, 0.37 mmol) and 1,1′-carbonyldiimidazole (43 mg, 0.27 mmol) in 3 mL of dichloromethane was stirred at room temperature for 5 h. The mixture was diluted with dichloromethane and washed with water and saturated aqueous NH₄Cl solution, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 96 mg (93%) of 25 as a white solid; mp >350° C; IR (film) 3288, 1730, 1107 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.16 (d, J = 7.7 Hz, 1H), 8.08 (s, 1H), 7.46–7.19 (m, 4 H), 7.09 (d, J = 7.7 Hz, 1H), 6.98–6.79 (m, 4H), 6.64 (d, J = 7.7 Hz, 1H), 5.13–4.99 (m, 1H), 4.40 (dd, J = 10.0, 4.5 Hz, 1H), 4.33 (dd, J = 9.9, 5.7 Hz, 1H), 4.28–4.14 (m, 3H), 3.99 (dd, J = 9.0, 6.0 Hz, 1H), 3.88–3.72 (m, 2H), 3.68 (s, 3H); ¹³C NMR (75 MHz, CDCl₃-CD₃OD) δ 158.4, 154.5, 149.6, 147.7, 141.4, 139.1, 126.3, 125.0, 122.7, 122.1, 122.0, 121.0, 119.2, 114.1, 112.2, 112.0, 110.2, 104.6, 100.5, 71.9, 68.0, 67.9, 55.6, 43.9; MS (EI), m/z (relative intensity) 432 (58) [M⁺], 183 (53), 44 (100). HRMS (EI) calcd for C₂₅H₂₄N₂O₅ [M⁺]: 432.1685; found: 432.1672.

Compounds 26 and 27 were prepared similarly.

5-[(9H-Carbazol-4-yloxy)methyl]-3-[2-(4,5-dichloro-2-methoxyphenoxy)ethyl]-2-oxazolidinone (26)⁴³

Yield: 65%; white solid; mp 104–106 °C; IR (film): 3290, 1749 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.12–8.05 (m, 2H), 7.44–7.20 (m, 4H), 7.13 (d, J = 7.7 Hz, 1H), 6.83 (d, J = 7.7 Hz, 1H), 6.67 (m, 2H), 5.08–5.02 (m, 1H), 4.43–4.39 (m, 2H), 4.14–4.04 (m, 4H), 3.85–3.62 (m, 2H), 3.52 (s, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 157.6, 154.4, 148.5, 146.9, 139.7, 137.5, 128.2, 126.8, 124.9, 124.6, 124.4, 123.5, 123.4, 115.5, 114.8, 113.8, 112.9, 107.9, 105.9, 71.3, 68.5, 68.3, 56.0, 48.6, 43.8; MS (EI), m/z (relative intensity) 500 (6) [M⁺], 222 (10), 68 (100). HRMS (EI) calcd for C₂₅H₂₂35Cl₂N₂O₅ [M⁺]: 500.0906; found: 500.0936.

5-[(9H-Carbazol-4-yloxy)methyl]-3-[2-(cyclohexyloxy)ethyl]-2-oxazolidinone (27)⁴³

Yield: 74%; white solid; mp 146–148 °C; IR (neat) 3290, 1732 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.22–8.14 (m, 2H), 7.45–7.19 (m, 4H), 7.10 (d, J = 7.7 Hz, 1H), 6.66 (d, J = 7.7 Hz, 1H), 5.08–4.98 (m, 1H), 4.46–4.36 (m, 2H), 4.08–4.00 (m, 1H) 3.94–3.83 (m, 2H), 3.68–3.45 (m, 3H), 3.24–3.16 (m, 1H), 1.85–1.39 (m, 6H), 1.28–1.04 (m, 4H); ¹³C NMR (75 MHz, CDCl₃) δ 157.8, 154.7, 141.1, 138.9, 126.7, 125.3, 123.1, 122.5, 120.0, 112.9, 110.2, 104.5, 101.2, 77.9, 71.2, 68.2, 66.5, 48.8, 44.8, 32.2, 25.8, 24.0; MS (EI), m/z (relative intensity) 408 (100) [M⁺], 183 (87). HRMS (EI) calcd for C₂₄H₂₈N₂O₄ [M⁺]: 408.2049; found 408.2027.

Preparation of 5-[(9H-carbazol-4-yloxy)methyl]-3-[2-(2-hydroxyphenoxy)ethyl]-2-oxazolidinone (28)

A solution of 25 (160 mg, 0.37 mmol) in dry dichloromethane (7 mL) was cooled in an ice bath and a 1.0 M solution of BBr₃ in dichloromethane (1.2 mL) was added dropwise. After 1 h, the reaction was warmed to room temperature and stirred an additional 1 h. The reaction was cooled in an ice bath and slowly quenched with water and diluted further with ethyl acetate. The organic phase was separated and washed with water and brine, dried over MgSO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford 131 mg (85%) of 28 as a white solid; mp 194–196 °C; IR (film) 3423, 3270, 2919, 2847, 1709, 1505, 1114, 746, 742 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.28 (s, 1H), 8.91 (s, 1H), 8.06 (d, J = 7.8 Hz, 1H), 7.45 (d, J = 8.1 Hz, 1H), 7.30–7.37 (m, 1H), 7.30 (dd, J = 8.0, 8.0 Hz, 1H), 7.15–7.07 (m, 2H), 6.91 (dd, J = 7.9, 1.3 Hz, 1H), 6.84–6.75 (m, 2H), 6.74–6.67 (m, 2H), 5.15–5.02 (m, 1H), 4.43 (dd, J = 10.8, 3.1 Hz, 1H), 4.34 (dd, J = 10.8, 4.8 Hz, 1H), 4.16 (t, J = 5.4 Hz, 2H), 4.02 (t, J = 9.2 Hz, 1H), 3.80–3.68 (m, 2H), 3.59 (dt, J = 14.5, 5.4 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.2, 154.2, 147.1, 146.3, 141.0, 138.8, 126.3, 124.6, 122.1, 121.7, 121.4, 119.1, 118.6, 115.8, 114.7, 111.4, 110.3, 104.2, 100.4, 68.1, 68.2, 66.8, 46.6, 43.2; MS (EI) m/z (relative intensity) 418 (100) [M⁺], 222 (57), 154 (23); HRMS (EI) calcd for C₂₄H₂₂N₂O₅ [M]⁺: 418.1529; found: 418.1524.

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[2-(2-hydroxyphenoxy)ethyl]amino}-2-propanol (9)^44,45

Compound 28 (77 mg, 0.18 mmol) was dissolved in ethanol (1 mL) and a 2 M NaOH solution (1.5 mL), and refluxed for 3.5 h. The mixture was cooled to room temperature, neutralized with a 1 M HCl solution, and extracted with ethyl acetate. The combined extracts were dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 56 mg (78%) of 9 as an off-white solid; mp 160–162 °C; IR (KBr) 3415, 1605, 1503, 1263, 1100, 755, 722 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.24 (s, 1H), 8.21 (d, J = 7.6 Hz, 1H), 7.43 (d, J = 8.1 Hz, 1H), 7.32 (ddd, J = 7.1, 7.0, 1.2 Hz, 1H), 7.27 (d, J = 8.0 Hz, 1H), 7.09 (ddd, J = 8.0, 7.0, 1.0, 1H), 7.06 (d, J = 8.0 Hz, 1H,), 6.91 (dd, J = 8.1, 1.3 Hz, 1H,), 6.82–6.74 (m, 2H), 6.73–6.68 (m, 1H), 6.68 (d, J = 8.1 Hz, 1H), 4.22–4.08 (m, 3H), 4.06–3.97 (m, 2H), 2.96–2.86 (m, 3H,) ), 2.80 (dd, J = 12.3, 6.9 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 154.9, 148.0, 146.6, 141.0, 138.8, 126.4, 124.4, 122.4, 122.0, 121.6, 119.0, 118.5, 116.0, 115.8, 111.5, 110.2, 103.7, 100.3, 70.4, 69.2, 68.3, 52.1, 48.2; MS (EI) m/z (relative intensity) 392 (69) [M⁺], 183 (100), 166 (30). HRMS (EI) calcd for C₂₃H₂₄N₂O₄ [M]⁺: 392.1736; found: 392.1731.

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]methylamino}-2-propanol (29)⁴⁵

A suspension of NaH (60% in oil) (10 mg, 0.25 mmol)) in anhydrous THF was cooled to 0 °C. A solution of carvedilol (1) (100 mg, 0.246 mmol) in THF was added and stirred for 20 min. at the same temperature, followed by iodomethane (35 mg, 0.25 mmol). The reaction mixture was stirred for 4 h at room temperature, quenched with water and extracted with ethyl acetate. The combined organic layers were washed with saturated NH₄Cl solution, dried over Na₂SO₄, evaporated under reduced pressure and the residue was purified by flash chromatography over silica gel to obtain 57 mg (54%) of 29 as viscous oil; IR (film) 3233, 2923, 1600, 1504, 1452, 1252, 732 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.29–8.20 (m, 2H), 7.41–7.31 (m, 3H), 7.28–7.26 m, 1H), 7.06 (d, J = 8.1 Hz, 1H), 6.93–6.87 (m, 4H), 6.66 (d, J = 8.1 Hz, 1H), 4.36–4.21 (m, 5H), 3.78 (s, 3H), 3.27–3.13 (m, 4H), 2.72 (s, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 154.9, 149.7, 147.6, 141.0, 138.8, 126.7, 125.0, 122.9, 122.5, 122.1, 120.9, 119.7, 114.3, 112.7, 111.9, 110.1, 104.0, 101.3, 69.9, 66.1, 66.0, 61.2, 56.4, 55.7, 43.0; MS (EI) m/z (relative intensity) 420 (5) [M⁺], 283 (41), 194 (100). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: 420.2049; found 420.2038.

Preparation of 1-{[2-(2-methoxyphenoxy)ethyl]amino}-3-[(9-methyl-9H-carbazol-4-yl)oxy]-2-propanol (30)^43,48

A solution of carvedilol (1) (50 mg, 0.12 mmol) and DABCO (2 mg) in dimethyl carbonate (4 mL) and DMF (1 mL) was heated at 95 °C for 18 h. The reaction mixture was partitioned between ether and water. The ether layer was washed with water and brine, dried over Na₂SO₄ and evaporated under reduced pressure. The residue was purified by flash chromatography on silica gel to give (41 mg, 77%) of the N-methyl derivative of 25 as an oil. The latter product was dissolved in ethanol, 2 N NaOH (2 mL) was added and the mixture was refluxed for 6 h. The ethanol was removed under vacuum and the residue was taken in ethyl acetate and washed with 1 M HCl. The aqueous layer was extracted with ethyl acetate and the combined organic layer was washed with water, brine, dried over Na₂SO₄ and evaporated under reduced pressure. The residue was purified by flash chromatography over silica gel to obtain 38 mg (73% overall from 1) of 30 as a white solid; mp 130–132 °C; IR (film) 3300, 1587, 1504, 1252 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.30 (d, J = 8.2 Hz, 1H), 7.48–7.36 (m, 3H), 7.24 (dd, J = 12.8, 5.1 Hz, 1H), 7.06 (d, J = 8.2 Hz, 1H), 6.98–6.88 (m, 4H), 6.70 (d, J = 8.2 Hz, 1H), 4.36–4.22 (m, 3H), 4.17 (t, J = 5.1 Hz, 2H), 3.85 (s, 3H), 3.84 (s, 3H), 3.18–3.06 (m, 3H), 3.00 (dd, J = 12.2, 6.9 Hz, 1H), 2.72 (br s, 1H); ¹³C NMR (75 MHz, CDCl₃) δ 155.3, 149.9, 148.3, 142.7, 140.4, 126.6, 125.0, 123.1, 122.2, 121.8, 121.0, 119.3, 114.4, 112.1, 112.0, 108.1, 101.9, 101.1, 70.5, 69.0, 68.6, 56.0, 52.1, 48.8, 29.4; MS (EI) m/z (relative intensity) 420 (13) [M⁺], 197 (100). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: 420.2049; found: 420.2085.

Preparation of 2-methoxy-N-[2-(2-methoxyphenoxy)ethyl]-N-methyl-3-[(9-methyl-9H-carbazol-4-yl)oxy]-1-propanamine (31)⁴³

A solution of epoxide 103a (307 mg, 1.28 mmol) in DMF (5 mL) was added dropwise to a mixture of 60% NaH (101 mg, 2.50 mmol) in DMF (5 mL), cooled in an ice bath. After 5 min, iodomethane (87 μL, 1.4 mmol) was added and the mixture was stirred at room temperature for 4 h. The reaction was quenched with water and brine, and diluted with ethyl acetate. The organic phase was separated and washed with brine, dried over Na₂SO₄ and concentrated under reduced pressure. The crude material was subjected to flash chromatography over silica gel (ethyl acetate-hexanes) to afford 300 mg (92%) of the corresponding N-methyl derivative 103b as a white solid; mp 76–77 °C; ¹H NMR (400 MHz, DMSO-d₆) δ 8.21 (d, J = 7.4 Hz, 1H), 7.57 (d, J = 8.2 Hz, 1H), 7.44 (ddd, J = 8.3, 7.2, 1.2 Hz, 1H), 7.39 (dd, J = 8.1, 8.1 Hz, 1H), 7.27 – 7.17 (m, 2H), 6.77 (d, J = 7.9 Hz, 1H), 4.58 (dd, J = 11.3, 2.6 Hz, 1H), 4.12 (dd, J = 11.3, 6.3 Hz, 1H), 3.86 (s, 3H), 3.58 – 3.51 (m, 1H), 2.94 (dd, J = 5.0, 4.3 Hz, 1H), 2.85 (dd, J = 5.1, 2.7 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 154.4, 142.0, 139.8, 126.6, 124.8, 122.3, 121.1, 118.9, 110.9, 108.67, 102.4, 101.1, 68.8, 49.9, 43.8, 29.1.

The above product (90 mg, 0.36 mmol) was refluxed with the N-methyl derivative of amine 104a (72 mg, 0.40 mmol) in isopropanol for 2 h. The solution was evaporated and the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to obtain 117 mg (76%) of the corresponding N,N-methylated product as a colorless oil; IR (film) 3496, 3059, 1589, 1503, 1466, 1252, cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.35 (d, J = 7.7 Hz, 1H), 7.49–7.34 (m, 3H), 7.28–7.19 (m, 1H), 7.03 (d, J = 8.1 Hz, 1H), 7.00–6.84 (m, 4H), 6.71 (d, J = 7.9 Hz, 1H), 4.58 (dd, J = 11.3, 2.6 Hz, 1H), 4.41–4.22 (m, 3H), 4.16 (t, J = 5.7 Hz, 2H), 3.85 (s, 3H), 3.83 (s, 3H), 3.18–3.03 (m, 1H), 3.00–2.84 (m, 3H), 2.51 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 155.4, 149.8, 148.4, 142.6, 140.4, 126.6, 124.8, 123.1, 122.2, 121.5, 120.9, 119.2, 113.7, 112.1, 112.0, 108.0, 101.8, 101.0, 70.4, 67.2, 67.0, 61.1, 56.8, 55.9, 43.5, 29.4; MS (EI) m/z (relative intensity) 434 (4) [M⁺], 297 (10), 194 (100). HRMS (EI) m/z calcd for C₂₆H₃₀N₂O₄ [M⁺]: 434.2206; found: 434.2206.

The above carvedilol derivative (186 mg, 0.428 mmol) in DMF (5 mL) was cooled in an ice bath and 60% NaH (34 mg, 0.85 mmol) was added. After 20 min, iodomethane (30 μL, 0.47 mmol) was added and the mixture stirred at room temperature for 5 h. The reaction was quenched with water and brine, and diluted with ethyl acetate. The organic phase was separated and washed with brine, dried over Na₂SO₄, filtered, and concentrated under reduced pressure. The crude material was subjected to flash chromatography over silica gel (methanol-dichloromethane) to afford 151 mg (79%) of 31 as a viscous, colorless oil; IR (film) 3062, 1591, 1465, 1249, 1104, 1026 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.37 (d, J = 8.0 Hz, 1H), 7.45 (ddd, J = 8.2, 7.1, 1.2, 1H), 7.42–7.32 (m, 2H), 7.23 (ddd, J = 8.0, 7.1, 1.1, 1H), 7.03 (d, J = 8.0 Hz, 1H), 6.95–6.74 (m, 4H), 6.70 (d, J = 7.8 Hz, 1H), 4.44–4.30 (m, 2H), 4.13 (t, J = 6.3 Hz, 2H), 3.97–3.89 (m, 1H), 3.84 (s, 3H), 3.81 (s, 3H), 3.61 (s, 3H), 2.99 (t, J = 6.3 Hz, 2H), 2.96–2.81 (m, 2H), 2.50 (s, 3H); ¹³C NMR (101 MHz, CDCl₃) δ 155.5, 149.6, 148.4, 142.6, 140.3, 126.5, 124.8, 123.2, 122.3, 121.2, 120.9, 119.3, 113.4, 112.1, 111.9, 107.9, 101.6, 100.9, 78.5, 68.5, 67.2, 59.2, 58.1, 57.1, 55.9, 44.3, 29.4; MS (EI) m/z (relative intensity) 448 (2) [M⁺], 194 (100). HRMS (EI) calcd for C₂₇H₃₂N₂O₄ [M⁺]: 448.2362; found: 448.2345.

Preparation of 6-[2-(9H-carbazol-4-yloxy)ethyl]-4-[2-(2-methoxyphenoxy)ethyl]-3-morpholinone (32)

Compound 32 was obtained from 2 by the same procedure used to obtain 17 from 1. Yield: 56%; white solid, mp 157–160 °C; IR (KBr) 3256, 1634, 1507, 1452, 1257, 1122, 1098, 722 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.36 (br s, 1H), 8.26 (d, J = 7.8 Hz, 1H), 7.39–7.36 (m, 2H), 7.32 (d, J = 8.1 Hz, 1H), 7.19–7.12 (m, 1H), 7.04 (d, J = 8.1 Hz, 1H), 6.98–6.90 (m, 4H), 6.69 (d, J = 8.0 Hz, 1H), 4.44–4.05 (m, 7H), 3.81 (s, 3H), 3.8 –3.74 (m, 2H), 3.70–3.66 (m, 2H), 2.26–2.12 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 167.1, 155.1, 149.4, 147.9, 141.0, 138.7, 126.6, 124.9, 122.7, 122.5, 121.6, 120.9, 119.5, 113.5, 112.6, 111.8, 110.0, 103.7, 101.0, 70.7, 67.8, 67.6, 63.6, 55.7, 53.6, 46.6, 32.7; MS (EI) m/z (relative intensity) 460 (14) [M⁺], 338 (20), 337 (100). HRMS (EI) calcd for C₂₇H₂₈N₂O₅ [M⁺]: 460.1998; found: 460.2005.

Preparation of 6-(9H-carbazol-4-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-hexanol (33)

The product was obtained from epoxide 106 and amine 104a by the same procedure as used to obtain 6. Yield: 54%; solid white foam; IR IR (film) 3398, 3227, 3055, 2935, 1608, 1501, 1453, 1250, 1092, 787, 749, 720 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.33 (d, J = 7.7 Hz, 1H), 8.28 (s, 1H), 7.42–7.20 (m, 4H), 7.01 (d, J = 8.0 Hz, 1H), 6.99–6.88 (m, 4H), 6.65 (d, J = 8.0 Hz, 1H), 4.22 (t, J = 6.3 Hz, 2H,), 4.09 (t, J = 5.1 Hz, 2H), 3.85 (s, 3H), 3.69–3.58 (m, 1H), 3.06–2.93 (m, 2H), 2.75 (dd, J = 12.0, 2.8 Hz, 1H,), 2.47 (dd, J = 12.0, 9.5 Hz, 1H,), 2.20–2.80 (br s, 2H), 2.05–1.96 (m, 2H), 1.82–1.48 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 155.8, 149.8, 148.4, 141.2, 138.9, 126.8, 125.0, 123.2, 122.9, 121.8, 121.1, 119.7, 114.3, 112.9, 112.1, 110.1, 103.5, 101.2, 69.4, 68.9, 67.9, 56.0, 55.2, 48.6, 34.8, 29.6, 22.5; MS (CI) m/z (relative intensity) 449 (100) [M + H]⁺. HRMS (CI) calcd for C₂₇H₃₃N₂O₄ [M + H]⁺: 449.2440; found: 449.2460.

Preparation of 1-(9H-carbazol-4-yloxy)-4-[[2-(2-methoxyphenoxy)ethyl]amino]-2-butanol (34)

4-Hydroxycarbazole (56 mg, 0.31 mmol), 107 (160 mg, 0.31 mmol) and K₂CO₃ (85 mg, 0.62 mmol) were heated in DMF (10 mL) at100 °C for 12 h. The reaction mixture was diluted with water (50 ml) and extracted with dichloromethane. The combined organic layers were dried over Na₂SO₄, the residue was purified by flash chromatography over silica gel to afford 120 mg (63%) of 108 as a colorless oil. The latter product (70 mg, 0.11 mmol) was dissolved in THF, TBAF in THF (0.22 mL, 1 M) was added, and the mixture was stirred at room temperature overnight. The solvent was removed under vacuum and the residue was chromatographed similarly to afford 24 mg (80%) of the corresponding diol as colorless oil. The diol (735 mg, 2.71 mmol), triethylamine (1.5 mL, 10.8 mmol), p-toluenesulfonyl chloride (1.03 g, 5.4 mmol) and DMAP (5 mol %) were stirred in dry chloroform at room temperature for 2 d. Concentration and flash chromatography afforded 200 mg (17%) of tosylate 109, along with 500 mg of recovered starting material. The tosylate (200 mg, 0.471 mmol), amine 104a (400 mg, 2.40 mmol) and LiBr (104 mg, 1.20 mmol) were heated briefly at 100 °C in DME (1 mL). The reaction mixture was then stirred for 2 d at room temperature, diluted with water (20 mL) and extracted with chloroform. The combined organic layers were dried over Na₂SO₄, concentrated and subjected to flash chromatography over silica gel to afford 100 mg (51%) of 34 as solid foam; IR (KBr) 3345, 2919, 1605, 1502, 1454, 1255, 1123, 1100, 749, 718 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.28 (d, J = 7.7 Hz, 1H), 8.15 (br s, 1H), 7.43–7.38 (m, 2H), 7.33 (t, J = 8.0 Hz, 1H), 7.23 (ddd, J = 8.0, 6.7, 1.5 Hz, 1H), 7.06 (d, J = 8.0 Hz, 1H), 7.00–6.90 (m, 4H), 6.70 (d, J = 8.0 Hz, 1H), 4.48–4.42 (m, 1H), 4.29 (dd, J = 9.2, 5.2 Hz, 1H), 4.18–4.12 (m, 2H), 3.87 (s, 3H), 3.22–2.98 (m, 5H), 2.10–2.03 (m, 1H), 1.94–1.84 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 155.3, 149.8, 148.1, 141.0, 138.8, 126.7, 124.9, 123.0, 122.6, 121.9, 121.0, 119.6, 114.5, 112.7, 111.9, 110.0, 103.7, 101.2, 71.6, 71.5, 68.4, 55.8, 48.4, 47.8, 31.8; MS (EI) m/z (relative intensity) 420 (11) [M⁺], 238 (46), 154 (100). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: for 420.2049; found: 420.2069.

Preparation of 7-[(9H-carbazol-4-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]-1,4-oxazepan-3-one (35)

Compound 35 was obtained from 34 by the same procedure used to obtain 17 from 1. Yield 23% (overall); viscous oil; IR (KBr): 3285, 2920, 1647, 1504, 1455, 1252, 1221, 1123, 1032, 752 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (br s, 1H), 8.24 (d, J = 7.4 Hz, 1H), 7.41–7.39 (m, 2H), 7.32 (t, J = 8.0 Hz, 1H), 7.23 (ddd, J = 8.1, 6.7, 4.0 Hz, 1H), 7.06 (d, J = 8.1 Hz, 1H), 6.97–6.87 (m, 4H), 6.65 (d, J = 8.0 Hz, 1H), 4.57 (d, J = 15.5 Hz, 1H), 4.36–4.31 (m, 2H), 4.27–4.10 (m, 4H), 3.98–3.83 (m, 3H), 3.80 (s, 3H), 3.76–3.70 (m, 1H), 2.39–2.25 (m, 1H), 2.15–2.08 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 172.1, 154.9, 149.4, 148.0, 140.9, 138.7, 126.6, 125.0, 122.8, 122.4, 121.5, 120.9, 119.6, 113.2, 112.7, 111.7, 110.03, 103.9, 101.2, 78.6, 72.3, 69.8, 67.7, 55.7, 49.0, 47.8, 31.9; MS (EI) m/z (relative intensity) 460 (16) [M⁺], 337 (100). HRMS (EI) calcd for C₂₇H₂₈N₂O₅ [M⁺]: 460.1998; found: 460.1990.

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[3-(2-methoxyphenyl)propyl]amino}-2-propanol (36)⁴³

Epoxide 103a (100 mg, 0.418 mmol) and amine 110 (151 mg, 0.836 mmol) were stirred for 24 h at 50° C in anhydrous DME (6 mL) in the presence of a catalytic amount of LiBr. The solvent was then removed under vacuum, the residue was taken up in ether (10 mL) and washed with water. The aqueous layer was extracted with ether and the combined organic layers were washed with brine, dried over Na₂SO₄ and evaporated under reduced pressure. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to obtain 86 mg (49%) of product 36 as a viscous oil; IR (film) 3352, 1504, 1452 cm⁻¹; ¹H NMR (300 MHz; CDCl₃) δ 8.29–8.24 (m, 2H), 7.42–7.28 (m, 2H), 7.22–7.18 (m, 1H), 7.06 (d, J = 8.2 Hz, 1H), 6.96–6.82 (m, 5H), 6.65 (d, J = 8.2 Hz, 1H), 4.39–4.09 (m, 2H), 4.12 (t, J = 5.1 Hz, 2H), 3.88–3.79 (m, 1H), 3.85 (s 3H), 3.60–3.20 m, 2H), 3.20–2.93 (m, 3H), 2.15–2.05 (m, 2H); ¹³C NMR (75 MHz; CDCl₃) δ 155.6, 149.7, 148.3, 141.1, 138.9, 126.9, 125.0, 123.0, 122.8, 121.8, 121.1, 119.7, 114.2, 112.7, 112.0, 110.2, 103.7, 101.3, 70.3, 68.1, 68.0, 56.1, 52.1, 47.7, 28.6; MS (EI) m/z (relative intensity) 420 (12) [M⁺], 183 (44), 154 (70), 45 (100). HRMS (EI) calcd for C₂₅H₂₈N₂O_4: 420.2049; found 420.2088.

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[2-(2-methoxybenzyloxy)ethyl]amino}-2-propanol (37)

The product was obtained from epoxide 103a and amine 111a by the same procedure used to obtain 6. Yield 82%; off-white solid; mp 94–95 °C; IR (film) 3402, 3291, 3050, 1606, 1455, 1243, 1100 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J = 7.8 Hz, 1H), 8.15 (s, 1H), 7.42–7.19 (m, 6H), 7.04 (d, J = 8.0 Hz, 1H), 6.93 (td, J = 7.4, 0.9 Hz, 1H), 6.86 (d, J = 8.2 Hz, 1H), 6.66 (d, J = 7.9 Hz, 1H), 4.59 (s, 2H), 4.33–4.15 (m, 3H), 3.82 (s, 3H), 3.67 (t, J = 5.1 Hz, 2H), 3.05 (dd, J = 12.3, 3.5 Hz, 1H), 3.02–2.86 (m, 5H); ¹³C NMR (101 MHz, CDCl₃) δ 157.4, 155.3, 141.1, 138.9, 129.4, 129.0, 126.8, 126.6, 125.1, 123.1, 122.7, 120.6, 119.8, 112.9, 110.5, 110.1, 104.0, 101.4, 70.4, 69.6, 68.5, 68.2, 55.5, 52.1, 49.4; MS (EI) m/z (relative intensity) 420 (8) [M⁺], 194 (46), 183 (100), 154 (48), 121 (92), 91 (50); HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M]⁺: 420.2049; found: 420.2056.

Preparation of 1-(9H-carbazol-4-yloxy)-3-{[2-(benzyloxy)ethyl]amino}-2-propanol (38)

The product was obtained from epoxide 103a and amine 111b by the same procedure used to obtain 6. Yield 72%; solid white foam; IR (film) 3405, 3299, 3056, 2919, 2856, 1603, 1455, 1100, 751, 720 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.27 (d, J = 7.8 Hz, 1H), 8.09 (s, 1H), 7.46–7.18 (m, 9H), 7.06 (d, J = 8.0 Hz, 1H), 6.68 (d, J = 8.0 Hz, 1H), 4.52 (s, 2H), 4.34–4.18 (m, 3H), 3.63 (t, J = 5.1 Hz, 2H), 3.06 (dd, J = 12.2, 3.4 Hz, 1H), 3.01–2.86 (m, 3H), 2.67 (br s, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 155.2, 141.1, 138.8, 138.2, 128.5, 127.9, 127.8, 126.7, 125.0, 123.0, 122.6, 119.7, 112.7, 110.1, 104.0, 101.3, 73.3, 70.4, 69.5, 68.5, 52.1, 49.4; MS (EI) m/z (relative intensity) 390 (5) [M⁺], 154 (38), 149 (86), 91 (100); HRMS (EI) calcd for C₂₄H₂₆N₂O₃ [M⁺]: 390.1943; found: 390.1939.

Preparation of 1-{-2-[(9H-carbazol-4-yloxy)ethyl]amino}-3-(2-methoxyphenyloxy)-2-propanol (39)

The product was obtained from epoxide 113 and amine 112 by the same procedure used to obtain 36. Yield 55%; solid off-white foam; IR (KBr) 3399, 1606, 1586, 1455, 1254, 1119, 751 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 7.8 Hz, 1H), 8.17 (br s, 1H), 7.40–7.35 (m, 2H), 7.31 (t, J = 8.0 Hz, 1H), 7.20 (ddd, J = 8.1, 6.4, 1.9, 1H), 7.04 (d, J = 8.0 Hz, 1H), 6.97–6.85 (m, 4H), 6.66 (d, J = 8.0 Hz, 1H), 4.35 (t, J = 5.3 Hz, 2H), 4.19–4.13 (m, 1H), 4.09–4.01 (m, 2H), 3.81 (s, 3H), 3.26 (dd, J = 5.8, 4.4 Hz, 2H), 3.22 (br s, 1H), 3.06 (dd, J = 12.2, 4.1 Hz 1H), 2.97 (dd, J = 12.2, 7.3–1H); ¹³C NMR (101 MHz, CDCl₃) δ 155.2, 149.9, 148.2, 140.9, 138.7, 126.6, 125.0, 122.9, 122.5, 122.0, 120.9, 119.7, 115.0, 112.3, 111.9, 110.0, 103.8, 101.2, 72.7, 68.2, 67.2, 55.8, 51.7, 48.9; MS (EI) m/z (relative intensity) 406 (5) [M⁺], 238 (100). HRMS (EI) calcd for C₂₄H₂₆N₂O₄ [M⁺]: 406.1893; found: 406.1904.

Preparation of 4-[2-(9H-carbazol-4-yloxy)ethyl]-6-(2-methoxyphenoxymethyl)morpholine-3-one (40)

Compound 40 was obtained from 39 by the same procedure used to obtain 17 from 1. Yield 52% (overall); solid white foam; IR (KBr) 3257, 1646, 1501, 1450, 768, 717 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.50 (br s, 1H), 8.27 (d, J = 7.8 Hz, 1H), 7.36–7.33 (m, 2H), 7.29 (d, J = 8.0 Hz, 1H), 7.15 (ddd, J = 8.0, 5.1, 3.1 Hz, 1H), 7.02 (d, J = 8.0 Hz, 1H), 6.97 (dd, J = 7.0, 1.3–1H), 6.89–6.86 (m, 2H), 6.79 (td, J = 7.8, 1.8 Hz, 1H), 6.63 (d, J = 8.0 Hz, 1H), 4.44–4.38 (m, 2H), 4.36 (d, J = 16.7 Hz, 1H), 4.21 (d, J = 16.6 Hz, 1H), 4.10–3.99 (m, 3H), 3.91–3.82 (m, 2H), 3.77 (s, 3H), 3.80–3.72 (m, 1H), 3.62 (dd, J = 11.9, 2.9 Hz, 1H); ¹³C NMR (75 MHz, CDCl₃) δ 167.0, 154.7, 149.8, 147.6, 141.0, 138.7, 126.6, 125.0, 122.6, 122.3, 120.8, 119.5, 114.8, 112.4, 111.9, 110.1, 104.0, 101.0, 71.8, 69.4, 67.6, 65.9, 55.6, 50.1, 46.6; MS (CI) m/z (relative intensity) 464 (23) [M+ NH₄]⁺, 447 (100) [M + H]⁺. HRMS (CI) calcd for C₂₆H₂₇N₂O₅ [M + H]⁺: 447.1920; found: 447.1942.

Preparation of 6-[(9H-carbazol-3-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]morpholine-3-one (41)

Compound 41 was obtained from 3 by the same procedure used to obtain 17 from 1. Yield 49% (overall); white solid; mp 63–65 °C; IR (KBr) 3458, 3378, 2922, 2834, 1507, 1452, 1253, 1222, 1186, 1121, 745 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 7.98 (d, J = 7.8 Hz, 1H), 7.96 (br s, 1H), 7.54 (d, J = 2.4 Hz, 1H), 7.43–7.36 (m, 2H), 7.32 (d, J = 8.7 Hz, 1H), 7.23–7.15 (m, 1H), 7.05 (dd, J = 8.7, 2.4 Hz, 1H), 6.95–6.82 (m, 4H), 4.40–4.03 (m, 7H), 3.78 (s, 3H), 3.92–3.76 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 167.1, 152.7, 149.7, 148.1, 140.5, 135.0, 126.2, 123.9, 123.3, 121.9, 120.4, 119.3, 115.6, 113.8, 112.1, 111.5, 111.0, 104.9, 72.2, 69.5, 68.0, 67.9, 56.0, 51.0, 47.0); MS (EI) m/z (relative intensity) 445 (20), 322 (100). HRMS (EI) calcd for C₂₆H₂₆N₂O₅ [M⁺]: 446.1842; found: 446.1861.

Preparation of 6-[(9H-carbazol-3-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]-1,3λ⁶,4-oxathiazinane-3,3-dione (42)

A suspension of 3 (101 mg, 0.249 mmol) and Et₃N (60 μL, 0.4 mmol) in dry dichloromethane (3 mL) was cooled in an ice bath. After 5 min, a solution of bromomethanesulfonyl chloride⁴⁹ (84 mg, 0.43 mmol) in dry dichloromethane (0.5 mL) was added dropwise. The ice bath was removed and the reaction was stirred at room temperature for 24 h. The reaction was concentrated under vacuum and the residue purified by flash chromatography over silica gel (ethyl acetate hexanes) to afford the intermediate sulfonamide as a solid white foam. A solution of the sulfonamide (48 mg, 0.086 mmol) in dry THF (2 mL) was cooled to 10 °C and treated with NaH (6 mg, 60% dispersion in oil, 0.15 mmol). The reaction was stirred for 20 h at room temperature, quenched with water and extracted with ethyl acetate. The combined organic extracts were dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford 28 mg (24% overall) of 42 as an off-white solid; mp 71–73 °C; IR (film) 3396, 3007, 2919, 1503, 1452, 1329, 1253, 1160, 1120, 745 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 11.05 (s, 1H), 8.06 (d, J = 7.6 Hz, 1H,), 7.72 (d, J = 1.6 Hz, 1H,), 7.47–7.29 (m, 3H), 7.15–6.83 (m, 6H), 5.02 (d, J = 11.7 Hz, 1H), 4.94 (d, J = 11.7 Hz, 1H), 4.44–4.37 (m, 1H), 4.16–4.10 (m, 4H), 3.72 (s, 3H), 3.92–3.55 (m, 4H,); ¹³C NMR (101 MHz, CDCl₃) δ 152.6, 149.7, 147.8, 140.5, 135.0, 126.2, 124.0, 123.3, 122.2, 121.1, 120.4, 119.4, 115.6, 114.0, 112.1, 111.5, 111.0, 105.0, 81.4, 74.5, 68.9, 68.7, 55.9, 54.2, 47.2; MS (CI) m/z (relative intensity) 500 [M + NH₄]⁺ (100), 418 (30), 354 (20). HRMS (EI) calcd for C₂₅H₂₆N₂O₆S [M⁺]: 482.1512; found: 482.1499.

Preparation of 4-(9H-carbazol-3-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-butanol (43)

Compound 43 was obtained from epoxide 114b and amine 104a by the same procedure as used to obtain 6. Yield: 62%; off-white solid; mp 126–128 °C; IR (KBr) 3408, 3299, 3060, 2940, 2877, 2834, 1588, 1495, 1459, 1250, 1183, 1123, 1024, 745 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 11.00 (s, 1H), 8.07 (d, J = 7.7 Hz, 1H), 7.67 (d, J = 2.3 Hz, 1H), 7.42 (d, J = 8.0 Hz, 1H), 7.39–7.29 (m, 2H), 7.09 (dd, J = 7.5, 7.4 Hz, 1H), 7.04–6.80 (m, 5H), 4.75 (d, J = 5.0 Hz, 1H), 4.15 (t, J = 6.3 Hz, 2H), 4.02 (t, J = 5.5 Hz, 2H), 3.85–3.77 (m, 1H), 3.74 (s, 3H), 2.92 (t, J = 5.5 Hz, 2H), 2.74–2.53 (m, 2H), 1.96–1.75 (m, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 152.2, 149.1, 148.0, 140.3, 134.4, 125.2, 122.7, 122.4, 121.0, 120.7, 120.2, 117.8, 115.1, 113.6, 112.2, 111.4, 110.9, 103.9, 68.2, 66.3, 65.2, 55.5, 55.4, 48.2, 34.8; MS (EI) m/z (relative intensity) 420 (100) [M⁺], 419 (32), 389 (17), 388 (53). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: 420.2049; found: 420.2044.

Preparation of 5-(9H-carbazol-3-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-pentanol (44)

Compound 44 was obtained from epoxide 114c and amine 104a by the same procedure as used to obtain 6. Yield: 56%; white solid; mp 116–118 °C; IR (film) 3402, 3236, 2942, 1500, 1449, 1249, 1180, 742 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 11.00 (s, 1H), 8.07 (d, J = 7.6 Hz, 1H), 7.66 (d, J = 2.3 Hz, 1H), 7.43 (d, J = 8.0 Hz, 1H,), 7.36 (d, J = 8.7 Hz, 1H,), 7.33 (dd, J = 7.2, 7.0 Hz, 1H,), 7.09 (dd, J = 7.6, 7.1 Hz, 1H), 7.00–6.81 (m, 5H), 4.67 (d, J = 4.1 Hz, 1H), 4.08–3.99 (m, 4H), 3.74 (s, 3H), 3.70–3.60 (m, 1H), 2.92 (t, J = 5.5 Hz, 2H), 2.71–2.49 (m, 2H), 1.95–1.45 (m, 4H); ¹³C NMR (101 MHz, DMSO-d₆) δ 152.2, 149.1, 148.0, 140.3, 134.4, 125.2, 122.7, 122.4, 121.0, 120.7, 120.2, 117.8, 115.1, 113.6, 112.2, 111.4, 110.8, 103.9, 68.9, 68.3, 68.2, 55.6, 55.4, 48.2, 31.6, 25.4; MS (EI) m/z (relative intensity) 434 (50) [M⁺], 252 (77), 180 (100), 154 (14). HRMS (EI) calcd for C₂₆H₃₀N₂O₄ [M⁺]: 434.2206; found: 434.2203.

Preparation of 6-(9H-carbazol-3-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-hexanol 45

Compound 45 was obtained from epoxide 114d and amine 104a by the same procedure as used to obtain 6. Yield: 54%; solid white foam; IR (film) 3406, 3234, 3060, 2938, 1502, 1250, 743 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.00 (d, J = 8.1 Hz, 1H), 7.98 (br s, 1H), 7.53 (d, J = 2.3 Hz, 1H), 7.40–7.33 (m, 2H), 7.30 (d, J = 8.7 Hz, 1H), 7.20–7.14 (m, 1H), 7.03 (dd, J = 8.7, 2.4 Hz, 1H), 6.96–6.86 (m, 4H), 4.10 (t, J = 5.2 Hz, 2H), 4.05 (t, J = 6.4 Hz, 2H), 3.83 (s, 3H), 3.70–3.60 (m, 1H), 3.08–2.98 (m, 2H), 2.81 (dd, J = 12.1, 2.9 Hz, 1H), 2.77–2.53 (br s, 2H), 2.51 (dd, J = 12.0, 9.5 Hz, 1H), 1.90–1.80 (m, 2H), 1.77–1.42 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 153.4, 149.8, 148.3, 140.5, 134.6, 125.9, 123.9, 123.5, 121.9, 121.1, 120.4, 119.1, 115.8, 114.4, 112.0, 111.4, 110.9, 104.5, 69.3, 68.0, 68.8, 56.0, 55.1, 48.5, 34.8, 29.7, 22.5; MS (CI) m/z (relative intensity) 449 (100) [M + H]⁺. HRMS (CI) calcd for C₂₇H₃₃N₂O₄ [M + H]⁺: 449.2440; found: 449.2437.

Preparation of 1-(9H-carbazol-3-yloxy)-4-{[2-(2-methoxyphenoxy)ethyl]amino}-2-butanol (46)

A solution of bromoalcohol 115 (151 mg, 0.452 mmol), amine 104a (149 mg, 0.892 mmol) and Et₃N (0.14 mL, 0.98 mmol) in methanol (2 mL) was heated at 60 °C for 18 h. The reaction mixture was diluted with water and extracted with dichloromethane. The combined organic extracts were washed with brine, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 94 mg (49%) of 46 as a white solid; mp 134–136 °C; IR (film) 3402, 3351, 2927, 2839, 1500, 1452, 1252, 1180, 1026, 745 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.01 (s, 1H), 8.07 (d, J = 7.8 Hz, 1H), 7.67 (d, J = 2.4 Hz, 1H), 7.43 (d, J = 8.0 Hz, 1H), 7.37 (d, J = 8.8 Hz, 1H), 7.33 (ddd, J = 8.0, 7.9, 1.2 Hz, 1H), 7.09 (ddd, J = 8.0, 7.9, 1.0 Hz, 1H), 7.02 (dd, J = 8.8, 2.5 Hz, 1H), 6.99–6.82 (m, 4H), 4.00 (t, J = 5.7 Hz, 2H), 3.98–3.90 (m, 3H), 3.74 (s, 3H), 2.90 (t, J = 5.7 Hz, 2H), 2.79 (t, J = 6.9 Hz, 2H), 1.80–1.75 (m, 1H), 1.65–1.58 (m, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 152.3, 149.2, 148.0, 140.3, 134.5, 125.2, 122.7, 122.4, 121.1, 120.7, 120.2, 117.9, 115.2, 113.8, 112.2, 111.4, 110.8, 104.0, 73.1, 68.1, 67.7, 55.4, 48.1, 46.1, 33.4; MS (EI) m/z (relative intensity) 420 (1) [M⁺], 238 (100), 180 (30). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: 420.2049; found: 420.2032.

Preparation of 1-(6-fluoro-9H-carbazol-3-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (47)

Compound 47 was obtained from epoxide 114e and amine 104a by the same procedure as used to obtain 6. Yield 53%; white solid; mp 62–64 °C; IR (KBr) 3382, 2927, 2836, 1575, 1497, 1456, 1286, 1249, 11955, 1120, 1023, 794, 756 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.05 (s, 1H), 7.91 (dd, J = 9.5, 2.6 Hz, 1H), 7.70 (d, J = 2.4 Hz, 1H), 7.42 (dd, J = 8.8, 4.4 Hz, 1H,), 7.37 (d, J = 8.8 Hz, 1H,), 7.18 (ddd, J = 9.4, 8.8, 2.6 Hz, 1H,), 7.05 (dd, J = 8.8, 2.5 Hz, 1H), 6.99–6.93 (m, 2H), 6.92–6.81 (m, 2H), 5.07 (d, J = 2.6 Hz, 1H,), 4.06–3.93 (m, 5H), 3.73 (s, 3H), 2.93 (t, J = 5.5 Hz, 2H), 2.83 (dd, J = 11.4, 3.7 Hz, 1H), 2.71 (dd, J = 11.8, 6.4 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 155.9 (d, ¹J_{C F} = 230 Hz), 152.1, 149.1, 148.0, 136.7, 135.6, 122.7 (d, ³J_{C F} = 10 Hz), 122.4 (d, ⁴J_{C F} = 4 Hz), 121.0, 120.6, 116.1, 113.6, 113.0 (d, ²J_{C F} = 25 Hz), 112.2, 111.8, 111.7 (CH, d, ³J_{C F} = 9 Hz), 105.6 (d, ²J_{C F} = 23 Hz), 104.1, 71.4, 68.2, 55.4, 52.4, 48.4; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −125.6; MS (EI) m/z (relative intensity) 424 (18) [M⁺], 201 (97), 180 (100), 172 (28), 44 (39). HRMS (EI) calcd for C₂₄H₂₅FN₂O₄ [M⁺]: 424.1798; found: 424.1790.

Preparation of 1-[(9H-carbazol-3-yl)amino]-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (48)

A mixture of 9-t-butyloxycarbonyl-3-aminocarbazole (576 mg, 2.04 mmol) and epichlorohydrin (0.11 mL, 1.4 mmol) in absolute ethanol (3.5 mL) was refluxed for 6 h. The reaction mixture was cooled to room temperature, concentrated under vacuum and the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 369 mg (70%) of 116 as a yellow foam. A mixture of 116 (201 mg, 0.536 mmol), 104a (177 mg, 1.06 mmol), K₂CO₃ (91 mg, 0.66 mmol) and catalytic KI in absolute ethanol (3.5 mL) was refluxed for 3 h. The reaction mixture was cooled to room temperature, filtered and washed with dichloromethane. The filtrate was concentrated under vacuum and the residue purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 177 mg (66%) of t-Boc-protected 48 as a yellow solid foam. A solution of the latter product (100 mg, 0.198 mmol) in dichloromethane (2.5 mL) was stirred in TFA (0.38 mL, 4.9 mmol) at room temperature for 3.5 h. The reaction mixture was treated with a 1 M NaOH and extracted with dichloromethane. The combined organic extracts were dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 52 mg (65%) of 48 as a white solid; mp 135–137 °C; IR (KBr) 3408, 3299, 3060, 2940, 2877, 2834, 1588, 1495, 1459, 1250, 1183, 1123, 1024, 745 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 10.75 (s, 1H), 7.94 (d, J = 7.6 Hz, 1H), 7.36 (d, J = 8.0 Hz, 1H), 7.32–7.20 (m, 3H,), 7.12–6.80 (m, 6H), 4.92 (br s, 1H,), 4.03 (t, J = 4.8 Hz, 2H,), 3.89–3.80 (m, 1H), 3.74 (s, 3H), 3.20 (dd, J = 12.2, 5.1 Hz, 1H,), 3.05 (dd, J = 12.2, 6.4 Hz, 1H,), 2.93 (t, J = 5.0 Hz, 2H,), 2.79 (dd, J = 11.6, 3.9 Hz, 1H,), 2.68 (dd, J = 11.6, 7.3 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 149.1, 148.0, 142.4, 140.0, 132.6, 124.7, 123.0, 122.3, 121.0, 120.6, 119.8, 117.4, 114.5, 113.7, 112.2, 111.3, 110.6, 101.0, 68.2, 68.1, 55.4, 53.6, 49.1, 48.3; MS (EI) m/z (relative intensity) 405 (100) [M⁺], 220 (50), 195 (80), 182 (40), 167 (33). HRMS (EI) calcd for C₂₄H₂₇N₃O₃ [M⁺]: 405.2052; found: 405.2038.

Compounds 49–58 were prepared in the usual manner, by conversion of the corresponding hydroxycarbazoles to the epoxides 117a-117e, followed by epoxide-opening with amines 104a or 104m-104o, as shown in Scheme 5. The lactams 49 and 51, and the oxazolidinone 52, were obtained by cyclization of the corresponding amino alcohols with chloroacetyl chloride and 1,1-carbonyldiimidazole, respectively.

6-[(9H-Carbazol-2-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]morpholine-3-one 49

Yield: 57% (overall from 4); white solid; mp 69–71 °C; IR (KBr) 3407, 3063, 2929, 2873, 1647, 1607, 1500, 1460, 1250, 1175, 1022, 747 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 11.12 (s, 1H), 7.99 (d, J = 7.6 Hz, 1H), 7.97 (d, J = 8.5 Hz, 1H), 7.42 (d, J = 8.0 Hz, 1H), 7.28 (dd, J = 7.9, 7.2 Hz, 1H), 7.10 (dd, J = 7.5, 7.2 Hz, 1H), 7.04–6.83 (m, 5H), 6.80 (dd, J = 8.5, 2.1 Hz, 1H,), 4.28–4.10 (m, 7H), 3.77 (s, 3H), 3.86–3.58 (m, 4H); ¹³C NMR (101 MHz, DMSO-d₆) δ 165.9, 157.3, 149.2, 147.7, 140.9, 139.7, 124.2, 122.5, 121.4, 120.9, 120.7, 119.2, 118.5, 116.5, 113.7, 112.4, 110.6, 107.8, 95.4, 71.5, 68.1, 66.8, 66.4, 55.6, 49.1, 45.6; MS (EI) m/z (relative intensity) 445 (15), 322 (75), 181 (49), 153 (100), 77 (21). HRMS (EI) m/z calcd for C₂₆H₂₆N₂O₅ [M⁺]: 446.1842; found: 446.1824.

4-(9H-Carbazol-2-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-butanol (50)

Yield: 65% from epoxide 117b and amine 104a; 39% overall from 2-hydroxycarbazole; mp 93–95 °C; IR (KBr) 3415, 3052, 2928, 2871, 1605, 1503, 1263, 1100, 755, 722 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.07 (s, 1H), 7.97 (d, J = 7.8 Hz, 1H), 7.94 (d, J = 8.5 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.27 (ddd, J = 8.2, 7.1, 1.2 Hz, 1H,), 7.09 (ddd, J = 7.9, 7.8, 1.0 Hz, 1H), 6.99–6.93 (m, 3H), 6.92–6.82 (m, 2H), 6.76 (dd, J = 8.5, 2.2 Hz, 1H), 4.75 (d, J = 4.1 Hz, 1H), 4.14 (t, J = 6.6 Hz, 2H), 4.01 (t, J = 5.6 Hz, 2H), 3.85–3.75 (m, 1H), 3.74 (s, 3H), 2.90 (t, J = 5.6 Hz, 2H), 2.64 (dd, J = 11.8, 4.2 Hz, 1H), 2.63 (dd, J = 11.8, 7.4 Hz, 1H,), 1.99–1.88 (m, 1H), 1.84–1.78 (m, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.8, 149.1, 148.0, 141.0, 139.6, 124.0, 122.6, 121.0, 120.8, 120.7, 119.1, 118.4, 116.0, 113.6, 112.2, 110.5, 108.0, 95.0, 68.3, 66.3, 64.7, 55.6, 55.4, 48.3, 34.7; MS (EI) m/z (relative intensity) 238 (100), 180 (45), 100 (16). HRMS (EI) calcd for C₂₅H₂₈N₂O₄ [M⁺]: 420.2049; found: 420.2029.

6-[2-(9H-Carbazol-2-yloxy)ethyl]-4-[2-(2-methoxyphenoxy)ethyl]-3-morpholinone (51)

Yield: 61% overall from 50; white solid; mp 160–161 °C; IR (film) 3396, 3002, 2932, 2876, 1641, 1503, 1460, 1255, 1219, 768 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.07 (s, 1H), 7.97 (d, J = 7.8 Hz, 1H), 7.95 (d, J = 8.6 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.27 (dd, J = 8.0, 7.1 Hz, 1H), 7.09 (dd, J = 7.5, 7.4 Hz, 1H), 7.01–6.94 (m, 5H), 6.76 (dd, J = 8.5, 1.9 Hz, 1H), 4.20–4.05 (m, 6H), 4.03–3.95 (m, 1H), 3.77–3.68 (m, 1H), 3.73 (s, 3H), 3.66–3.49 (m, 3H), 2.08–1.94 (m, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 166.0, 157.5, 149.1, 147.7, 140.9, 139.7, 124.1, 122.5, 121.3, 120.8, 120.7, 119.2, 118.4, 116.2, 113.6, 112.3, 110.5, 107.9, 95.2, 70.1, 67.0, 66.3, 63.7, 55.5, 52.1, 45.4, 32.0; MS (EI) m/z (relative intensity) 460 (24) [M⁺], 337 (100). HRMS (EI) calcd for C₂₇H₂₈N₂O₅ [M⁺]: 460.1998; found: 460.1988.

5-[2-(9H-Carbazol-2-yloxy)ethyl]-3-[2-(2-methoxyphenoxy)ethyl]-2-oxazolidinone (52)

Yield: 87% overall from 50; white solid; mp 61–63 °C; IR (film) 3399, 3320, 3002, 2926, 1739, 1500, 1460, 1249, 749 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.09 (s, 1H), 7.98 (d, J = 7.8 Hz, 1H), 7.95 (d, J = 8.5 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.28 (dd, J = 7.8, 7.3 Hz, 1H), 7.10 (dd, J = 7.6, 7.3 Hz, 1H), 7.01–6.83 (5H, m), 6.76 (dd, J = 8.5, 1.9 Hz, 1H,), 4.80–4.70 (m, 1H), 4.21–4.11 (m, 2H), 4.09 (t, J = 5.3 Hz, 2H), 3.88 (t, J = 8.6 Hz, 1H,), 3.73 (s, 3H), 3.58–3.50 (m, 3H), 2.19–2.11 (2H, m); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.4, 157.1, 149.3, 147.6, 140.9, 139.7, 124.1, 122.5, 121.5, 120.8, 120.7, 119.2, 118.4, 116.3, 114.1, 112.4, 110.5, 107.9, 95.2, 70.9, 66.6, 63.7, 55.5, 50.1, 43.1, 33.9; MS (EI) m/z (relative intensity) 446 (100) [M⁺], 236 (48). HRMS (EI) calcd for C₂₆H₂₆N₂O₅ [M⁺]: 446.1842; found: 446.1835.

1-(6-Fluoro-9H-carbazol-2-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (53)

Yield: 54% from epoxide 117c and amine 104a; 38% overall from 6-fluoro-2-hydroxycarbazole; white solid; mp 157–159 °C; IR (KBr) 3388, 3059, 2924, 2855, 1631, 1503, 1487, 1456, 1249, 1164, 1104, 1035, 819, 747 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.10 (s, 1H,), 7.97 (d, J = 7.8 Hz, 1H), 7.81 (dd, J = 9.5, 2.6 Hz, 1H), 7.40 (dd, J = 8.8, 4.4 Hz, 1H), 7.11 (ddd, J = 9.5, 8.8, 2.6 Hz, 1H), 6.99–6.81 (m, 5H), 6.77 (dd, J = 8.6, 2.2 Hz, 1H), 5.08 (br s, 1H), 4.07–3.94 (m, 5H), 3.74 (s, 3H), 2.93 (t, J = 5.5 Hz, 2H), 2.82 (dd, J = 12.0, 4.2 Hz, 1H), 2.71 (dd, J = 11.7, 6.2 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 158.2, 156.4 (d, ¹J_{C F} = 230 Hz), 149.1, 148.0, 142.1, 136.1, 123.2 (d, ³J_{C F} = 10 Hz), 121.3, 121.0, 120.6, 115.9 (d, ⁴J_{C F} = 4.0 Hz), 113.7, 112.2, 111.3 (d, ²J_{C F} = 33 Hz), 111.2, 108.3, 104.9 (d, ²J_{C F} = 24 Hz), 95.2, 70.9, 68.2, 68.1, 55.4, 52.3, 48.3; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −125.2; MS (EI) m/z (relative intensity) 424 (5) [M⁺], 368 (10), 201 (34), 180 (100), 56 (34). HRMS (EI) calcd for C₂₄H₂₅N₂O₄F [M⁺]: 424.1798; found: 424.1807.

1-(6,8-Difluoro-9H-carbazol-2-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (54)

Yield: 55% from epoxide 117d and amine 104a; 33% overall from 6,8-difluoro-2-hydroxycarbazole; white solid; mp 136–138 °C; IR (KBr) 3309, 3176, 2927, 2860, 1652, 1632, 1592, 1505, 1256, 1117, 984, 838, 815, 735 cm-1; ¹H NMR (400 MHz, DMSO-d₆) δ 11.55 (s, 1H), 7.99 (d, J = 8.6 Hz, 1H), 7.71 (d, J = 7.7 Hz, 1H), 7.17 (t, J = 9.5 Hz, 1H,), 7.05–6.80 (m, 6H), 5.10 (br s, 1H), 4.09–3.92 (m, 5H), 3.73 (s, 3H), 2.92 (t, J = 5.1 Hz, 2H), 2.87–2.66 (m, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 158.9, 155.5 (dd, J_{C F} = 233, 9.9 Hz), 149.2, 148.0, 147.3 (dd, J_{C F} = 242, 13.9 Hz), 142.3, 125.7 (dd, J_{C F} = 11.3, 7.2 Hz), 123.8 (d, J_{C F} = 12.6 Hz), 121.8, 121.1, 120.7, 116.0 (dd, J_{C F} = 4.2, 4.1 Hz), 113.7, 112.2, 109.2, 101.2 (dd, J_{C F} = 23, 3.7 Hz), 98.9 (dd, J_{C F} = 29, 21 Hz), 95.4, 71.0, 68.3, 68.2, 55.5, 52.3, 48.4; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −122.5, −130.4; MS (EI) m/z (relative intensity) 442 (9) [M⁺], 219 (13), 180 (100). HRMS (EI⁺) calcd for C₂₄H₂₄F₂N₂O₄ [M⁺]: 442.1704; found: 442.1715.

1-(9H-Carbazol-2-yloxy)-3-{[2-(4-fluoro-2-methoxyphenoxy)ethyl]amino}-2-propanol (55)

Yield: 60% from epoxide 117a and amine 104m; 37% overall from 2-hydroxycarbazole; white solid; mp 141–143 °C; IR (KBr) 3400, 3303, 3247, 3081, 2927, 2839, 1609, 1503, 1462, 1173, 1032, 948, 750, 728 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) 11.07 (s, 1H), 7.97 (d, J = 7.8 Hz, 1H), 7.94 (d, J = 8.6 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.27 (td, J = 8.2, 1.2 Hz, 1H), 7.09 (td, J = 7.9, 1.0 Hz, 1H), 6.99–6.92 (m, 2H), 6.88 (dd, J = 10.7, 3.0 Hz, 1H), 6.77 (dd, J = 8.6, 2.2 Hz, 1H), 6.65 (td, J = 8.6, 3.0 Hz, 1H), 5.08 (d, J = 4.0 Hz, 1H), 4.06–3.92 (m, 5H), 3.75 (s, 3H), 2.90 (t, J = 5.5 Hz, 2H), 2.80 (dd, J = 11.8, 4.0 Hz, 1H), 2.69 (dd, J = 11.8, 6.4 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.8, 156.8 (d, ¹J_{C F} = 235 Hz), 150.2 (d, ³J_{C F} = 10 Hz), 144.4 (d, ⁴J_{C F} = 2.0 Hz), 141.0, 139.6, 124.0, 122.6, 120.8, 119.1, 118.4, 116.1, 114.4 (d, ³J_{C F} = 10 Hz), 110.5, 108.0, 105.5 (d, ²J_{C F} = 22 Hz), 100.6 (d, ²J_{C F} = 27 Hz), 95.2, 70.9, 69.1, 68.2, 55.8, 52.3, 48.4; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −120.4; MS (EI) m/z (relative intensity) 424 (28) [M⁺], 198 (39), 183 (100), 154 (65), 56 (37). HRMS (EI) calcd for C₂₄H₂₅N₂O₄F [M⁺]: 424.1798, found: 424.1792.

1-(9H-carbazol-2-yloxy)-3-{[2-(2-trifluoromethylphenoxy)ethyl]amino}-2-propanol (56)

Yield: 52% from epoxide 117a and amine 104n; 32% overall from 2-hydroxycarbazole; white solid; mp 138–140 °C; IR (film) 3400, 3292, 1607, 1455, 1319, 1131, 1034, 766, 749 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.05 (s, 1H), 7.97 (d, J = 7.7 Hz, 1H), 7.94 (d, J = 8.6 Hz, 1H), 7.57–7.65 (m, 2H), 7.40 (d, J = 8.0 Hz, 1H), 7.32–7.23 (m, 2H), 7.14–7.03 (m, 2H), 6.95 (d, J = 2.2 Hz, 1H), 6.76 (dd, J = 8.5, 2.2 Hz, 1H), 5.03 (d, J = 4.6 Hz, 1H), 4.17 (t, J = 5.2 Hz, 2H), 4.07–3.90 (m, 3H), 2.96 (t, J = 5.5 Hz, 2H), 2.86–2.65 (m, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.8, 156.3, 140.9, 139.6, 134.1, 126.6 (q, ³J_{C F} = 5 Hz), 124.0 (CH), 123.7 (q, ¹J_{C F} = 270 Hz), 122.5, 120.7, 120.1, 119.1, 118.4, 117.1 (q, ²J_{C F} = 30 Hz), 116.1, 113.6, 110.5, 108.0, 95.2, 70.8, 68.5, 68.2, 52.2, 48.0; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −60.7; MS (EI) m/z (relative intensity) 444 (10) [M⁺], 198 (25), 183 (100). HRMS (EI) calcd for C₂₄H₂₃N₂O₃F₃ [M⁺]: 444.1661; found: 444.1663.

1-(9H-carbazol-2-yloxy)-3-{[2-(2-fluorophenoxy)ethyl]amino}-2-propanol (57)

Yield: 58% from epoxide 117a and amine 104o; 36% overall from 2-hydroxycarbazole; white solid; mp 160–162 °C; IR (KBr) 3397, 3303, 3068, 2924, 2848, 1609, 1509, 1456, 1311, 1286, 1199, 1173, 1108, 738, 722 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.05 (s, 1H), 7.97 (d, J = 7.8 Hz, 1H), 7.94 (d, J = 8.6 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.27 (ddd, J = 8.2, 7.1, 1.2 Hz, 1H), 7.23–7.06 (m, 4H), 6.96 (d, J = 2.1 Hz, 1H,), 6.95–6.90 (m, 1H), 6.77 (dd, J = 8.5, 2.2 Hz, 1H,), 5.05 (d, J = 4.5 Hz, 1H), 4.11 (t, J = 5.6 Hz, 2H), 4.07–3.90 (m, 3H), 2.95 (t, J = 5.5 Hz, 2H), 2.81 (dd, J = 11.8, 3.9 Hz, 1H), 2.71 (dd, J = 11.8, 6.5 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.8, 151.7 (d, ¹J_{C F} = 241 Hz), 146.5 (d, ³J_{C F} = 10 Hz), 141.0, 139.6, 124.7 (d, ⁴J_{C F} = 3.0 Hz), 124.0, 122.6, 121.0 (d, ³J_{C F} = 7.0 Hz), 120.7, 119.1, 118.4, 116.1, 115.9 (d, ²J_{C F} = 18 Hz), 115.0, 110.5, 108.0, 95.2, 70.9, 68.6, 68.2, 52.3, 48.2; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −134.9; MS (EI) m/z (relative intensity) 394 (20) [M⁺], 183 (100), 168 (46), 154 (40), 56 (27). HRMS (EI) calcd for C₂₃H₂₃FN₂O₃ [M⁺]: 394.1693; found: 394.1679.

1-(9H-carbazol-1-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (58)⁵⁰

Yield: 66% from epoxide 117e and amine 104a; 44% overall from 1-hydroxycarbazole; white solid; mp 58–60 °C; IR (film) 3215, 3057, 2927, 2833, 1576, 1502, 1452, 1250, 738 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 11.17 (s, 1H), 8.06 (d, J = 7.8 Hz, 1H), 7.68 (d, J = 7.7 Hz, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.36 (dd, J = 7.2, 7.2 Hz, 1H), 7.13 (dd, J = 7.4, 7.3 Hz, 1H), 7.05 (dd, J = 7.8, 7.8 Hz, 1H), 6.99–6.80 (5H, m), 5.07 (d, J = 4.0 Hz, 1H), 4.20–4.00 (m, 5H), 3.73 (s, 3H), 2.95 (t, J = 5.4 Hz, 2H), 2.99–2.73 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 149.1, 148.0, 144.8, 139.4, 129.8, 125.2, 123.5, 122.6, 121.0, 120.7, 120.1, 119.0, 118.4, 113.7, 112.6, 112.2, 111.3, 107.1, 70.7 (2 signals), 68.2, 55.4, 52.1, 48.3; MS (EI) m/z (relative intensity) 405 (45), 223 (18), 182 (55), 181 (63), 179 (98), 153 (100), 123 (34), 77 (30), 56 (63). HRMS (EI) calcd for C₂₄H₂₆N₂O₄ [M⁺]: 406.1893; found: 406.1880.

Preparation of 1-[4-(2-hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy-9H-carbazol-9-yl]octadecan-1-one (59)

Epoxide 103a (700 mg, 2.93 mmol) was dissolved in dry THF and cooled to 0 °C. Sodium hydride (220 mg, 60% dispersion in oil, 5.5 mmol) was added, the mixture was stirred for 45 min and then warmed to room temperature. Octadecanoyl chloride (1.26 g, 4.16 mmol) in THF was added and the reaction mixture was stirred for 1 h at room temperature, quenched with water and the aqueous phase was exacted with chloroform and ethyl acetate. The combined organic layers were washed with brine and dried over Na₂SO₄. After removal of the solvent under reduced pressure, the residue was purified by flash chromatography over silica gel (dichloromethane-hexanes) to afford product 1.26 g, (85%) of epoxide 103c.

Epoxide 103c (200 mg, 0.396 mmol) and amine 104a (132 mg, 0.792 mmol) were reacted in the usual manner to afford 88 mg (33%) of 59 as a white solid; mp 94–95 ºC; IR (KBr) 3451, 2922, 2836, 1705, 1594, 1507, 1441, 1237, 739, 717 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.31 (d, J = 7.4 Hz, 1H), 8.20 (d, J = 8.3 Hz, 1H), 7.80 (d, J = 8.4 Hz, 1H), 7.45–7.31 (m, 3H), 6.95–6.81 (m, 5H), 4.28–4.13 (m, 5H), 3.82 (s, 3H), 3.14–2.95 (m, 6H), 1.97–1.87 (m, 2H), 1.28 (br s, 28H), 0.90 (t, J = 6.6 Hz, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 173.5, 154.6, 149.6, 148.0, 139.7, 137.8, 127.7, 126.2, 125.5, 123.6, 123.1, 121.6, 120.8, 115.7, 115.3, 114.0, 111.7, 109.1, 105.6, 70.5, 68.6, 68.2, 55.7, 51.9, 48.6, 39.2, 31.9, 29.6, 29.6, 29.5, 29.3, 29.2, 24.7, 22.6, 14.1; MS (EI) m/z (relative intensity) 672 (2) [M]⁺, 549 (10), 183 (60), 180 (100). HRMS (EI) calcd for C₄₂H₆₀N₂O₅ [M⁺]: 672.4502; found: 672.4504.

4-[2-(2-Methoxyphenoxy)ethyl]-6-{[(9-octadecanoyl-9H-carbazol-4-yl)oxy]methy}morpholin-3-one (60)

The product was prepared by the acylation of 17 with octadecanoyl chloride, as in the preceding procedure. Yield: 80%; white solid; mp 98–99 °C; IR (KBr) 1704, 1639, 1500, 1257, 1160, 752, 739, 721 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.29 (d, J = 7.7 Hz, 1H), 8.20 (d, J = 8.4 Hz, 1H), 7.90 (d, J = 8.4 Hz, 1H), 7.45 (d, J = 8.9 Hz, 1H), 7.39 (d, J = 8.5 Hz, 1H), 7.28–7.24 (m, 1H), 6.98–6.91 (m, 3H), 6.84 (t, J = 7.3 Hz, 2H), 4.45–4.23 (m, 7H), 3.99–3.80 (m, 4H), 3.68 (s, 3H), 3.14 (t, J = 7.4 Hz, 2H), 1.98–1.88 (d, J = 7.2 Hz, 2H), 1.27 (br s 28H), 0.89 (t, J = 6.6 Hz, 3H); ¹³C NMR (75 MHz, CDCl₃) δ 173.6, 166.8, 154.3, 149.5, 147.9, 140.00, 137.9, 127.8, 126.5, 125.3, 123.7, 123.2, 121.8, 120.9, 115.7, 115.6, 113.8, 111.8, 109.7, 105.6, 72.0, 68.4, 68.0, 67.8, 55.6, 51.0, 46.9, 39.3, 31.9, 29.7 (2 signals), 29.6, 29.5, 29.4, 29.3, 24.7, 22.7, 14.1; MS (CI) m/z 713 (71) [M + H]⁺, 447 (100). HRMS (EI) calcd for C₄₄H₆₀N₂O₆: 712.4451; found: 712.4418 [M⁺].

Compounds 61, 63, 64 and 66–80 were prepared by alkylation of the corresponding phenols or alcohols with 3-chloro-1,2-epoxypropane or 4-bromo-1,2-epoxybutane, followed by epoxide–opening with amine 104a, as in the preparation of 6.

1-{[2-(2-Methoxyphenoxy)ethyl]amino}-3-(2,3,4,9-tetrahydro-1H-carbazol-6-yloxy)- 2-propanol (61)

Yield: 75% from epoxide 103d; 53% overall from the corresponding phenol; white solid; mp 114–116 °C; IR (film) 3388, 3309, 3060, 2930, 2837, 1592, 1505, 1456, 1253, 1123, 1024, 908, 738 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 7.55 (br s, 1H), 7.12 (d, J = 8.4 Hz, 1H), 6.96–6.84 (m,5H), 6.75 (dd, J = 8.7, 2.5 Hz, 1H), 4.13 (t, J = 5.3 Hz, 2H), 4.13–4.07 (m, 1H), 4.02 (d, J = 5.2 Hz, 2H), 3.82 (s, 3H), 3.08 (t, J = 5.3 Hz, 2H), 2.98 (dd, J = 12.2, 3.9 Hz, 1H), 2.88 (dd, J = 12.2, 7.8 Hz, 1H), 2.69 (t, J = 5.9 Hz, 2H), 2.63 (t, J = 5.8 Hz, 2H), 1.93–1.80 (m, 4H); ¹³C NMR (101 MHz, CDCl₃) δ 153.1, 150.1, 148.4, 135.4, 131.2, 128.5, 122.0, 121.1, 114.7, 112.2, 111.1, 110.3, 102.0, 71.7, 69.0, 68.7, 56.1, 52.0, 48.9, 23.6, 23.5, 23.4, 21.1; MS (EI) m/z (relative intensity) 410 (30) [M⁺], 187 (100), 180 (25), 158 (24). HRMS (EI) calcd for C₂₄H₃₀N₂O₄ [M]⁺: 410.2266; found: 410.2208.

4-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy)-9H-fluoren-9-one (63)

Yield: 40% from epoxide 103e; 53% overall from the corresponding phenol; yellow solid, mp 97–99 °C; IR (KBr) 3326, 1710, 1598, 1505, 1251, 726 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 7.81 (d, J = 7.4 Hz, 1H), 7.63 (d, J = 7.3 Hz, 1H), 7.42 (t, J = 7.5 Hz, 1H), 7.30 (d, J = 7.2 Hz, 1H), 7.25 (d, J = 8.0 Hz, 1H), 7.21 (d, J = 7.3 Hz, 1H), 7.06 (d, J = 8.2 Hz, 1H), 6.95–6.87 (m, 4H), 4.21–4.15 (m, 6H), 3.83 (s, superimposed on m, 4H), 3.14–3.11 (m, 2H), 3.07 (dd, J = 12.2, 3.2 Hz, 1H), 2.96–2.89 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 194.1, 154.5, 149.6, 148.0, 143.7, 135.8, 134.9, 133.5, 131.4, 130.4, 128.1, 124.2, 124.0, 121.7, 120.9, 118.8, 116.9, 114.0, 111.8, 70.7, 68.7, 68.1, 55.7, 51.7, 48.6; MS (CI) m/z (relative intensity) 420 (100) [M + H]⁺. HRMS (CI) calcd for C₂₅H₂₆NO₅ [M + H]⁺: 420.1811; found: 420.1815.

1-{[2-(2-Methoxyphenoxy)ethyl]amino}-1-{8-oxatricyclo[7.4.0.0^2,7]trideca-1(9),2(7),3,5,10,12-hexaen-4-yloxy}-2-propanol (64)

Yield: 56% from epoxide 103f; 42% overall from the corresponding phenol; white solid; mp 110–112 °C; IR (nujol) 3257, 1461, 1371, 1247, 1171, 738 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 8.12 (dd, J = 7.8, 1.9 Hz, 1H), 7.73 (d, J = 2.5 Hz, 1H), 7.65 (dd, J = 8.2, 0.8 Hz, 1H), 7.58 (d, J = 8.9 Hz, 1H), 7.49 (ddd, J = 8.6, 8.4, 1.4 Hz, 1H), 7.36 (ddd, J = 7.7, 7.5, 1.0 Hz, 1H), 7.10 (dd, J = 8.9, 2.7 Hz, 1H), 6.99–6.93 (m, 2H), 6.92–6.82 (m, 2H), 5.09 (d, J = 4.4 Hz, 1H), 4.09–3.93 (m, 5H), 3.73 (s, 3H), 2.93 (t, J = 5.5 Hz, 2H), 2.82 (dd, J = 11.9, 4.3 Hz, 1H), 2.72 (dd, J = 11.9, 6.7 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 156.1, 155.1, 150.0, 149.2, 148.1, 127.4, 124.1, 123.9, 122.7, 121.2, 121.0, 120.7, 115.9, 113.7, 112.2, 112.1, 111.6, 105.1, 71.5, 68.4, 68.3, 55.4, 52.4, 48.5; MS (EI) m/z (relative intensity) 284 (6), 270 (7), 210 (8), 180 (100). HRMS (EI) calcd for C₂₄H₂₅NO₅ [M⁺]: 407.1733; found: 407.1733.

1--{[2-(2-Methoxyphenoxy)ethyl]amino}-1-(10H-phenothiazin-2-yloxy)-2-propanol (66)

Yield: 63% from epoxide 103g; 33% overall from the corresponding phenol; off-white solid; mp 48–50 °C; IR (KBr) 3388, 3059, 2924, 2855, 1631, 1503, 1487, 1456, 1249, 1164, 1104, 1035, 819, 747 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 8.54 (s, 1H), 7.02–6.82 (m, 5H), 6.79 (d, J = 8.4 Hz, 1H), 6.74 (ddd, J = 7.5, 7.5, 1.0 Hz, 1H), 6.67 (dd, J = 7.9, 0.8 Hz, 1H), 6.38 (dd, J = 8.4, 2.5 Hz, 1H), 6.34 (d, J = 2.5 Hz, 1H), 5.03 (br s, 1H), 4.00 (t, J = 5.5 Hz, 2H), 3.93–3.75 (m,3H), 3.73 (s, 3H), 2.89 (t, J = 5.5 Hz, 2H), 2.73 (dd, J = 11.8, 4.1 Hz, 1H), 2.64 (dd, J = 11.8, 6.2 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 158.6, 149.1, 148.0, 143.2, 141.7, 127.2, 126.7, 126.1, 121.6, 121.0, 120.6, 116.9, 114.3, 113.6, 112.2, 107.8, 107.0, 101.2, 70.6, 68.3, 68.0, 55.4, 52.2, 48.4; MS (EI) m/z (relative intensity) 438 (100) [M⁺], 224 (22), 215 (82). HRMS (EI) calcd for C₂₄H₂₆N₂O₄S [M⁺]: 438.1613; found: 438.1600.

2-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy)-10H-5λ6,10-phenothiazine-5,5-dione (67)

Yield: 54% from epoxide 103h; 28% overall from the corresponding phenol; white solid; mp 67–69 °C; IR (film) 3518, 3309, 3183, 3076, 2930, 2834, 2249, 1622, 1260, 1024, 911, 725 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.70 (s, 1H), 7.94 (dd, J = 8.0, 1.1 Hz, 1H), 7.77 (d, J = 8.9 Hz, 1H), 7.31 (t, J = 8.4 Hz, 1H), 7.07 (t, J = 7.4 Hz, 1H), 6.96 (d, J = 8.3 Hz, 1H), 6.94–6.81 (m, 4H), 6.57 (dd, J = 8.9, 2.1 Hz, 1H), 6.34 (d, J = 2.0 Hz, 1H), 4.09 (t, J = 4.9 Hz, 2H), 4.07–3.98 (m, 1H), 3.90–3.78 (m, 2H), 3.76 (s, 3H), 3.27 (br s, 2H), 3.03 (t, J = 4.9 Hz, 2H), 2.87 (dd, J = 12.3, 4.0 Hz, 1H), 2.76 (dd, J = 12.3, 7.8 Hz, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 162.2, 149.6, 148.1, 139.9, 138.1, 133.0, 124.9, 123.0, 122.0, 121.8, 121.6, 121.3, 116.8, 114.3, 114.2, 112.2, 110.6, 100.3, 70.8, 68.5, 68.1, 56.0, 51.5, 48.8; MS (EI) m/z (relative intensity) 470 (3) [M⁺], 347 (10), 333 (13), 247 (13), 180 (100), 178 (25), 148 (12), 56 (20). HRMS (EI) calcd for C₂₄H₂₆N₂O₆S [M+]: 470.1512; found: 470.1490.

1--{[2-(2-Methoxyphenoxy)ethyl]amino}-3-(naphthalen-1-yloxy)-2-propanol (68)

Yield: 38% from epoxide 103i; 32% overall from the corresponding phenol; white solid; mp 110–112 °C; IR (KBr) 3435, 1504, 1256, 782, 773, 743 cm⁻¹; ¹H NMR (300 MHz, DMSO-d₆) δ 8.24 (d, J = 7.5 Hz, 1H), 7.85 (d, J = 7.5 Hz, 1H), 7.35–7.55 (m, 4H), 6.80–7.04 (m, 5H), 5.16 (d, J = 3.9 Hz, 1H), 3.97–4.19 (m, 5H), 3.72 (s, 3H), 2.92 (t, J = 5.5 Hz, 2H), 2.87 (dd, J = 11.7, 3.7 Hz, 1H), 2.77 (dd, J = 12.0, 6.3 Hz, 1H), 1.98 (br s, 1H); ¹³C NMR (75 MHz, DMSO-d₆) δ 154.2, 149.2, 148.1, 134.0, 127.4, 126.4, 126.2, 125.1, 125.0, 121.8, 121.0, 120.7, 119.8, 113.6, 112.2, 105.1, 70.9, 68.4, 68.4, 55.4, 52.5, 48.5; MS (CI) m/z (relative intensity) 368 (100) [M + H]⁺. HRMS (EI) calcd for C₂₂H₂₅NO₄ [M⁺]: 367.1784; found: 367.1797.

1--{[2-(2-Methoxyphenoxy)ethyl]amino}-4-(naphthalen-1-yloxy)-2-butanol (69)

Yield: 51% from 103u; 12% overall from the corresponding phenol; white solid; mp 65–67 ºC IR (KBr) 3310, 2917, 1591, 1578, 1504, 1454, 1391, 1252, 1127, 1098, 770 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.27 (ddd, J = 6.7, 1.7, 0.7 Hz, 1H), 7.82–7.80 (m, 1H), 7.50–7.46 (m, 2H), 7.44 (d, J = 8.3 Hz, 1H), 7.38 (t, J = 8.3 Hz, 1H), 6.97–6.84 (m, 5H), 4.38–4.29 (m, 2H), 4.12 (t, J = 5.2 Hz, 2H), 4.07–4.01 (m, 1H), 3.85 (s, 3H), 3.12–3.02 (m, 2H), 2.94 (dd, J = 12.1, 3.2 Hz, 1H), 2.68 (dd, J = 12.1, 9.2 Hz, 1H), 2.14–1.99 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 154.5, 149.7, 148.2, 134.4, 127.4, 126.3, 125.9, 125.6, 125.1, 121.9, 121.6, 120.9, 120.1, 114.1, 111.8, 104.70, 68.7, 66.9, 65.00, 55.7, 55.1, 48.4, 34.5; MS (EI) m/z (relative intensity) 381 (<1) [M⁺] 238 (100), 180 (74). HRMS (EI) calcd for C₂₃H₂₇NO₄ [M⁺]: 381.1940; found: 381.1941.

1-(Adamantan-1-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (70)

Yield: 50% from epoxide 103j; 13% overall from 1-adamantanol; viscous oil; IR (KBr) 3428, 2904, 1498, 1252, 1119, 742 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 6.93–6.87 (m, 4H), 4.12 (t, J = 5.3 Hz, 2H), 3.85 (s, 3H), 3.85–3.77 m, 1H), 3.47–3.38 (m, 2H), 3.05 (t, J = 5.3 Hz, 2H), 2.82 (dd, J = 12.0, 4.0 Hz, 1H), 2.72 (dd, J = 12.1, 7.6 Hz, 1H), 2.60 (br s, 1H), 2.09–2.17 (m, 3H), 1.69–1.78 (m, 6H), 1.54–1.68 (m, 6H); ¹³C NMR (75 MHz, CDCl₃) δ 149.6, 148.2, 121.4, 120.8, 114.0, 111.8, 72.2, 69.3, 68.7, 62.5, 55.8, 52.1, 48.7, 41.4, 36.3, 30.4; MS (CI) m/z (relative intensity) 376 (100) [M + H]⁺. HRMS (CI) calcd for C₂₂H₃₄NO₄ [M + H]⁺: 376.2488; found: 376.2475.

1-(Adamantan-2-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (71)

Yield: 50% from epoxide 103k; 32% overall from 2-adamantanol; white solid; mp 53–57 ºC; IR (KBr) 3334, 2896, 1509, 1256, 740 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 6.97–6.86 (m, 4H), 4.13 (t, J = 5.4 Hz, 2H), 3.86 (s, 3H), 3.92–3.84 (m, 1H), 3.52–3.42 (m, 3H), 3.07 (t, J = 5.4 Hz, 2H), 2.85 (dd, J = 12.1, 4.2 Hz, 1H), 2.77 (dd, J = 12.1, 7.5 Hz, 1H), 1.96–2.07 (m, 4H), 1.73–1.88 (m, 4H), 1.70–1.62 (m, 4H), 1.43–1.52 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 149.7, 148.2, 121.5, 120.8, 114.1, 111.8, 82.0, 70.00, 69.1, 68.8, 55.8, 52.2, 48.7, 37.5, 36.4, 31.63, 31.59, 31.5, 27.3; MS (CI) m/z (relative intensity) 376 (100) [M + H]⁺. HRMS (CI) calcd for C₂₂H₃₄NO₄ [M + H]⁺: 376.2488; found: 376.2501.

1-(Adamantan-1-ylmethoxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (72)

Yield: 87% overall from (1-adamantyl)methanol via epoxide 103l; viscous oil; IR (KBr)) 3211, 1596, 1509, 1452, 1254, 1125, 1029, 744 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 6.96–6.88 (m, 4H), 4.12 (t, J = 5.3 Hz, 2H), 3.86 (s, 3H), 3.90–3.83 (m, 1H), 3.37–3.47 (m, 2H), 3.05 (t, J = 5.4 Hz, 2H), 2.97–3.07 (m, 2H), 2.82 (dd, J = 12.1, 4.1 Hz, 1H), 2.73 (dd, J = 12.1, 7.7 Hz, 1H), 1.91–2.02 (m, 3H), 1.58–1.78 (m, 6H), 1.49–1.56 (m, 6H); ¹³C NMR (75 MHz, CDCl₃) δ 149.7, 148.1, 121.6, 120.9, 114.3, 111.8, 82.5, 74.0, 68.6, 68.5, 55.8, 52.0, 48.6, 39.6, 37.1, 34.1, 28.2; MS (CI) m/z (relative intensity) 390 (100) [M + H]⁺. HRMS (CI) calcd for C₂₃H₃₆NO₄ [M + H]⁺: 390.2644; found: 390.2631.

6-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy)-1,2-dihydroquinolin-2-one (73)

Yield: 40% from epoxide 103m; 9% overall from the corresponding phenol; white solid; mp 154–155 °C; IR (film) 3283, 2909, 1654, 1502, 1249, 1119 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.60 (br s, 1H), 7.82 (d, J = 9.6 Hz, 1H), 7.10–7.25 (m, 3H), 6.80–6.99 (m, 4H), 6.47 (d, J = 9.5 Hz, 1H,), 5.05 (br s, 1H), 3.87–4.05 (m, 5H), 3.73 (s, 3H), 2.91 (t, J = 5.4 Hz, 2H), 2.78 (dd, J = 11.8, 3.6 Hz, 1H), 2.68 (dd, J = 11.7, 6.0 Hz, 1H,); ¹³C NMR (101 MHz, DMSO-d₆) δ 161.4, 153.5, 149.2, 148.1, 139.7, 133.3, 122.2, 121.0, 120.7, 119.9, 119.6, 116.3, 113.7, 112.3, 110.2, 71.1, 68.3, 68.1, 55.5, 52.3, 48.4; MS (ESI) m/z (relative intensity), 385 (100) [M + H]⁺. HRMS (ESI) calcd for C₂₁H₂₅N₂O₅ [M + H]⁺: 385.1758; found: 385.1754.

6-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy)-1,2,3,4-tetrahydroquinolin-2-one (74)

Yield: 29% from epoxide 103n; 10% overall from the corresponding phenol; white solid; mp 126–128 °C; IR (film) 3302, 3167, 2920, 2830, 1625, 1593, 1503, 1450, 1252, 1121, 1022, 743 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 9.87 (br s, 1H), 6.96 (d, J = 7.6, 2.1 Hz, 2H), 6.93–6.83 (m, 2H), 6.81–6.68 (m, 3H), 4.98 (br s, 1H), 4.00 (t, J = 5.6 Hz, 2H), 3.92–3.80 (m, 3H), 3.74 (s, 3H), 2.90 (t, J = 5.5 Hz, 2H), 2.82 (t, J = 7.5 Hz, 2H), 2.75 (dd, J = 12.0, 3.7 Hz, 1H), 2.65 (dd, J = 11.8, 6.1 Hz, 1H), 2.39 (dd, J = 8.3, 6.8 Hz, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 169.7, 153.8, 149.2, 148.1, 131.7, 124.8, 121.0, 120.7, 115.7, 114.0, 113.7, 113.0, 112.3, 71.0, 68.3, 68.1, 55.5, 52.3, 48.4, 30.3, 25.1; MS (ESI) m/z (relative intensity) 387 (100) [M + H]⁺. HRMS (ESI) m/z (relative intensity) calcd for C₂₁H₂₇N₂O₅ [M + H]⁺: 387.1914; found: 387.1910.

7-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy)-1,2,3,4-tetrahydroquinolin-2-one (75)

Yield: 65% from epoxide 103o; 13% overall from the corresponding phenol; white solid; mp 161–163 °C; IR (film) 3584, 3183, 2914, 2831, 1678, 1588, 1223, 1123, 1027, 738 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 9.96 (br s, 1H), 7.14–6.78 (m, 5H), 6.62–6.37 (m, 2H), 5.03 (br s, 1H), 4.01 (t, J = 5.3 Hz, 2H), 3.95–3.76 (m, 3H), 3.74 (s, 3H), 2.91 (t, J = 5.3 Hz, 2H), 2.78 (t, J = 7.3 Hz, 2H), 2.79–2.71 (m, 1H), 2.66 (dd, J = 11.7, 6.2 Hz, 1H), 2.41 (t, J = 7.4 Hz, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 170.2, 157.9, 149.2, 148.0, 139.1, 128.3, 121.1, 120.7, 115.5, 113.8, 112.3, 107.5, 101.7, 70.6, 68.3, 68.0, 55.5, 52.2, 48.4, 30.7, 24.0; MS (ESI) m/z (relative intensity) 387 (100) [M + H]⁺; HRMS (ESI) calcd for C₂₁H₂₇N₂O₅ [M + H]⁺: 387.1914; found: 387.1909.

1-(1H-Indol-4-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (76)⁵¹

Yield: 63% from epoxide 103p; 43% overall from 4-hydroxyindole; white solid; mp 98–100 °C; IR (film) 3378, 3066, 2924, 2868, 2834, 1586, 1506, 1453, 1249, 1122, 1091, 1051, 1027, 909. 742 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.20 (br s, 1H), 7.11–7.00 (m, 3H), 6.97–6.83 (m, 4H), 6.65–6.59 (m, 1H,), 6.51 (dd, J = 7.6, 0.7 Hz, 1H), 4.24–4.08 (m, 5H), 3.81 (s, 3H), 3.20–3.10 (br s, 1H), 3.10 (t, J = 5.2 Hz, 2H,), 3.02 (dd, J = 12.4, 3.5 Hz, 1H), 2.93 (dd, J = 12.4, 7.5 Hz, 1H), 2.96–2.92 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 152.6, 150.1, 148.4, 137.6, 123.0, 122.9, 122.0, 121.2, 119.0, 114.7, 112.2, 105.0, 101.1, 100.1, 70.6, 69.0, 68.5, 56.1, 52.0, 48.9; MS (EI) m/z (relative intensity) 356 (25) [M⁺], 180 (100), 133 (35). HRMS (EI) calcd for C₂₀H₂₄N₂O₄ [M⁺]: 356.1736; found: 356.1727.

1-(1H-Indol-5-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (77)

Yield: 58% from epoxide 103q; 44% overall from 5-hydroxyindole; white solid; mp 109–110 °C; IR (film) 3375, 2930, 2867, 1592, 1505, 1456, 1253, 1220, 1157, 1123, 1027, 748, 727 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 10.89 (s, 1H), 7.28–7.24 (m, 2H), 7.03 (d, J = 2.4 Hz, 1H), 6.98–6.93 (m, 2H), 6.92–6.82 (m, 2H), 6.73 (dd, J = 8.7, 2.4 Hz, 1H), 6.32–6.30 (m, 1H), 5.00 (br s, 1H), 4.01 (t, J = 5.6 Hz, 2H), 3.95–3.85 (m, 3H), 3.73 (s, 3H), 3.32 (br s, 1H), 2.92 (t, J = 5.6 Hz, 2H), 2.80 (dd, J = 11.9, 3.9 Hz, 1H), 2.68 (dd, J = 11.9, 6.4 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 152.5, 149.2, 148.0, 131.0, 127.9, 125.7, 121.0, 120.7, 113.7, 112.2, 111.8, 111.6, 102.8, 100.8, 71.3, 68.3, 68.2, 55.4, 52.5, 48.4; MS (ESI) m/z (relative intensity) 357 (100 %) [M + H]⁺. HRMS (ESI) calcd for C₂₀H₂₄N₂O₄ [M + H]⁺: 357.1809; found: 357.1819.

Preparation of 1-(1H-indazol-5-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (78)

The reaction of the N-t-Boc-protected epoxide derivative 103r with amine 104a was carried out as in the preparation of 6, followed by deprotection with TFA in dichloromethane at room temperature, to afford 78 in 43% overall yield; white solid; mp 114–116 °C; IR (film) 3000–3600 (br), 3062, 2924, 2848, 1591, 1500, 1450, 1249, 1221, 1123, 1026, 948, 744 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 7.96 (br s, 1H), 7.37 (d, J = 8.8 Hz, 1H), 7.15–7.04 (m, 2H), 6.84–7.02 (m, 4H), 4.17 (t, J = 5.1 Hz, 2H), 4.20–4.11 (m, 1H), 4.04 (d, J = 5.1 Hz, 2H), 3.84 (s, 3H), 3.13 (t, J = 5.0 Hz, 2H), 3.03 (dd, J = 12.3, 3.7 Hz, 1H), 2.91 (dd, J = 12.2, 8.0 Hz, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 153.9, 150.0, 148.3, 135.9, 134.6, 123.5, 122.1, 121.1, 119.5, 114.8, 112.2, 110.8, 101.6, 71.2, 68.9, 68.2, 56.0, 51.8, 48.8; MS (ESI) m/z (relative intensity) 358 (100%) [M + H]⁺. HRMS (ESI) calcd for C₁₉H₂₄N₃O₄ [M + H]⁺: 358.1761; found: 358.1756.

Products 79 and 80 were prepared similarly.

1-(1H-indazol-6-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (79)

Overall yield from 103s: 47%; white solid; mp 131–133 °C; IR (film) 3300, 3018, 2933, 2870, 1628, 1503, 1456, 1252, 1123, 1026, 941, 741 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 7.94 (br s, 1H), 7.56 (d, J = 8.8 Hz, 1H), 7.02–6.77 (m, 6H), 4.30–4.22 (m, 1H), 4.20 (t, J = 5.1 Hz, 2H), 4.10–4.01 (m, 2H), 3.83 (s, 3H), 3.20 (dd, J = 8.1, 4.8 Hz, 2H), 3.14 (dd, J = 12.3, 3.9 Hz, 1H), 3.01 (dd, J = 12.3, 8.2 Hz, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 158.6, 149.6, 147.9, 141.3, 134.2, 122.1, 121.6, 121.2, 118.1, 114.5, 113.4, 112.2, 91.9, 70.6, 68.0, 67.7, 55.9, 51.7, 48.4; MS (ESI) m/z (relative intensity) 358 (100) [M⁺]. HRMS (ESI) calcd for C₁₉H₂₄N₃O₄ [M + H]⁺: 358.1761; found: 358.1752.

1-(1H-Benzodiazol-5-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (80)

Overall yield from 103t: 20%; white solid; mp 125–127 °C; IR (film) 3302, 3167, 2920, 2830, 1625, 1593, 1503, 1450, 1252, 1121, 1022, 743 cm⁻¹; ¹H NMR (400 MHz, CD₃OD) δ 8.05 (s, 1H), 7.48 (d, J = 8.8 Hz, 1H), 7.13 (s, 1H), 7.03–6.84 (m, 5H), 6.51 (dd, J = 7.6, 0.7 Hz, 1H), 4.18–4.01 (m, 5H), 3.80 (s, 3H), 3.03 (t, J = 5.0 Hz, 2H), 2.96 (dd, J = 12.2, 4.0 Hz, 1H), 2.85 (dd, J = 12.2, 8.0 Hz, 1H), 2.96–2.92 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 154.3, 148.3, 146.7, 139.2, 120.1, 119.2, 119.0, 112.9, 111.2, 110.5, 100.0, 69.6, 67.0, 66.8, 53.5, 50.3, 46.7; MS (EI) m/z (relative intensity) 179 (100), 133 (35). HRMS (ESI) calcd for C₁₉H₂₄N₃O₄ [M + H]⁺: 358.1761; found: 358.1760.

Preparation of 3-(9H-Fluoren-4-yloxy)-1-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (62)

The product was prepared by the Wolff-Kishner reduction of 63 in 54% yield; white solid; mp 104.5–106.0 ºC; IR (KBr) 3290, 2922, 1582, 1503, 1457, 1274, 1253, 1221, 738 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.14 (d, J = 7.5 Hz, 1H), 7.53 (d, J = 7.3 Hz, 1H), 7.36 (t, J = 7.1 Hz, 1H), 7.30–7.28 (m, 1H), 7.24 (d, J = 7.8 Hz, 1H), 7.18 (d, J = 7.3 Hz, 1H), 6.98–6.88 (m, 5H), 4.30–4.14 (m, 5H), 3.92 (s, 2H), 3.84 (s, 3H), 3.14–3.07 (m, 3H), 2.97 (dd, J = 7.7, 12.3 Hz, 1H); ¹³C NMR (75 MHz, CDCl₃) δ 154.9, 149.7, 148.2, 145.3, 142.5, 140.8, 129.9, 127.6, 126.7, 125.8, 124.3, 123.6, 121.6, 120.9, 117.6, 114.1, 111.8, 109.6, 70.4, 68.8, 68.4, 55.7, 51.9, 48.6, 37.2; MS (EI) m/z (relative intensity) 405 (3) [M⁺], 268 (25), 180 (100). HRMS (EI) calcd for C₂₅H₂₇NO₄ [M⁺]: 405.1940; found: 405.1945.

Preparation of 3-(2-Hydroxy-3-{[2-(2-methoxyphenoxy)ethyl]amino}propoxy-N-phenylaniline (65)

A mixture of 66 (88 mg, 0.20 mmol) and NiCl₂·6H₂O (337 mg, 1.41 mmol) in methanol-THF-H₂O (8 mL; 1:2:1) at room temperature was treated with small portions of NaBH₄ (162 mg, 4.28 mmol) over 1 h.³⁴ Stirring was continued for an additional 2 h, the mixture was filtered through a pad of Celite and the filtrate was concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 29 mg (36%) of 65 as a yellow oil; IR (film) 3355, 3279, 3061, 2928, 2835, 1588, 1495, 1251, 745 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 7.28–7.21 (m, 3H), 7.11 (t, J = 8.0 Hz, 1H), 7.08–7.02 (m, 2H), 6.97–6.83 (m, 5H), 6.66–6.58 (m, 2H), 6.44 (dd, J = 8.2, 2.0 Hz, 1H), 4.14 (t, J = 5.1 Hz, 2H), 4.15–4.07 (m, 1H), 4.00–3.92 (m, 2H), 3.81 (s, 3H), 3.10 (t, J = 5.1 Hz, 2H), 3.00 (dd, J = 12.3, 3.7 Hz, 1H), 2.88 (dd, J = 12.3, 8.0 Hz, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 159.9, 150.0, 148.2, 144.9, 142.9, 130.3, 129.5, 122.2, 121.5, 121.2, 118.6, 115.0, 112.2, 110.6, 106.9, 104.1, 70.4, 68.7, 68.0, 56.0, 51.7, 48.7; MS (EI) m/z (relative intensity) 408 (40) [M⁺], 368 (19), 285 (19), 186 (19), 185 (100), 180 (73). HRMS (EI) calcd for C₂₄H₂₈N₂O₄ [M⁺]: 408.2049; found: 408.2030.

Preparation of 1-[(benzofuran-2-ylmethyl)amino]-3-(9H-carbazol-2-yloxy)-2-propanol (81)

A mixture of 117a (304 mg, 1.27 mmol) and benzylamine (0.42 mL, 3.84 mmol) were refluxed for 2 h in isopropanol (3 mL). The solvent was removed under vacuum and the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to afford 211 mg (48%) of amino alcohol 119 as an off-white solid; mp 160–161 °C; IR (film) 3392, 3043, 2919, 2847, 1607, 1455, 749, 724 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.06 (s, 1H), 7.97 (d, J = 8.2 Hz, 1H), 7.94 (d, J = 9.2 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.38–7.20 (m, 6H), 7.09 (dd, J = 7.7, 7.2 Hz, 1H), 6.96 (s, 1H), 6.76 (d, J = 8.6 Hz, 1H), 4.09–3.93 (m, 3H), 3.77 (s, 2H), 2.73 (dd, J = 11.7, 3.5 Hz, 1H), 2.65 (dd, J = 11.6, 5.9 Hz, 1H); ¹³C NMR (101 MHz, d₆-DMSO) δ 157.8, 141.0, 140.3, 139.7, 128.1, 128.0, 126.6, 124.1, 122.6, 120.8, 119.2, 118.5, 116.2, 110.5, 108.1, 95.3, 70.9, 68.1, 52.9, 51.6; MS (EI) m/z (relative intensity) 346 (32) [M⁺], 183 (100), 154 (20), 120 (18), 91 (48). HRMS (EI) calcd for C₂₂H₂₂N₂O₂ [M⁺]: 346.1681; found: 346.1686.

A mixture of 119 (188 mg, 0.542 mmol), aldehyde 121 (85 mg, 0.58 mmol) and NaBH(OAc)₃ (168 mg, 0.792 mmol) in 1,2-dichloroethane (5 mL) was stirred at room temperature for 4 h. The mixture was partitioned between water and dichlormethane and the aqueous phase was extracted with dichloromethane. The combined organic extracts were washed with brine, dried over MgSO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to furnish 196 mg (76%) of the N-benzyl derivative of 81 as a white solid foam; ¹H NMR (400 MHz, CDCl₃) δ 7.94 (d, J = 7.7 Hz, 1H), 7.88 (d, J = 8.4 Hz, 1H), 7.87 (br s, 1H), 7.54–7.50 (m, 1H), 7.48–7.44 (m, 1H), 7.40–7.31 (m, 6H), 7.29–7.16 (m, 4H), 6.84–6.76 (m, 2H), 6.58 (s, 1H), 4.14–4.23 (m, 1H), 4.03 (d, J = 5.1 Hz, 2H), 3.90 (d, J = 15.1 Hz, 1H), 3.89 (d, J = 13.5 Hz, 1H), 3.84 (d, J = 15.1 Hz, 1H), 3.70 (d, J = 13.5 Hz, 1H), 3.31 (s, 1H), 2.77–2.92 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 158.3, 155.3, 155.1, 140.9, 139.7, 138.4, 129.3, 128.7, 128.4, 127.6, 124.8, 124.2, 123.6, 122.9, 121.1, 121.0, 119.8, 119.7, 117.6, 111.4, 110.5, 108.8, 106.0, 95.8, 70.9, 67.0, 58.7, 56.5, 50.7.

A solution of the above N-benzyl derivative (50 mg, 0.10 mmol) in a 2:1 mixture of methanol-dichloromethane (1.5 mL) was added to 10% palladium on charcoal (27 mg). The mixture was heated at 45 °C for 4 h under positive pressure of hydrogen (balloon). The reaction was cooled to room temperature and filtered through Celite. The filtrate was concentrated under vacuum and the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to provide 27 mg (68%) of 81 as a white solid; mp 159–160 °C; IR (film) 3355, 3279, 3061, 2928, 2835, 1588, 1495, 1251, 745 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.04 (s, 1H), 7.97 (d, J = 7.6 Hz, 1H), 7.94 (d, J = 8.6 Hz, 1H), 7.56 (d, J = 8.4 Hz, 1H), 7.51 (d, J = 8.0 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.31–7.17 (m, 3H), 7.09 (dd, J = 7.7, 7.2 Hz, 1H), 6.96 (d, J = 2.2 Hz, 1H), 6.76 (dd, J = 8.5, 2.2 Hz, 1H), 6.73 (s, 1H), 5.03 (d, J = 4.5 Hz, 1H), 3.92–4.09 (m, 2H), 3.91 (s, 3H), 2.79 (dd, J = 11.8, 4.3 Hz, 1H), 2.70 (dd, J = 11.8, 6.0 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.8, 157.7, 154.1, 140.9, 139.6, 128.1, 124.0, 123.5, 122.6, 122.5, 120.7, 120.6, 119.1, 118.4, 116.1, 110.7, 110.4, 108.0, 103.1, 95.2, 70.8, 68.2, 51.7, 46.0; MS (EI) m/z (relative intensity) 386 (74) [M⁺], 183 (100), 131 (82), 43 (54). HRMS (EI) calcd for C₂₄H₂₂N₂O₃ [M⁺]: 386.1630; found: 386.1626.

Preparation of 1-[(benzoxazol-2-ylmethyl)amino]-3-(9H-carbazol-2-yloxy)-2-propanol (82)

A mixture of amino alcohol 119 (88 mg, 0.25 mmol), chloride 122 (47 mg, 0.28 mmol), N,N-diisopropylethylamine (71 μL, 0.41 mmol) and a catalytic amount of KI in acetonitrile (2 mL) was stirred at 60 °C for 16 h. The reaction was cooled to room temperature and partitioned between water and ethyl acetate. The organic phase was separated and extracted with ethyl acetate. The combined extracts were washed with brine, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to provide 101 mg (85%) of the N-benzyl derivative of 82 as an off-white solid; mp 77–79 °C; ¹H NMR (400 MHz, DMSO-d₆) δ 11.07 (s, 1H), 7.98 (d, J = 7.8 Hz, 1H), 7.92 (d, J = 8.5 Hz, 1H), 7.79–7.73 (m, 1H), 7.72–7.66 (m, 1H), 7.46–7.21 (m, 9H), 7.15–7.06 (m, 1H), 6.91 (d, J = 2.1 Hz, 1H), 6.67 (dd, J = 8.5, 2.2 Hz, 1H), 5.01 (d, J = 4.8 Hz, 1H), 4.13–4.01 (m, 4H), 3.94–3.89 (m, 1H), 3.90 (d, J = 16.0 Hz, 1H), 3.83 (d, J = 16.0 Hz, 1H), 2.85 (dd, J = 13.3, 5.9 Hz, 1H), 2.77 (dd, J = 13.3, 5.8 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 164.0, 157.8, 150.2, 141.0, 140.6, 139.7, 138.7, 128.8, 128.2, 127.0, 125.0, 124.3, 124.0, 122.6, 120.7, 119.6, 119.2, 118.5, 116.1, 110.7, 110.5, 108.0, 95.2, 70.9, 67.5, 58.4, 56.3, 50.5; MS (EI) m/z (relative intensity) 477 (7) [M⁺], 345 (21), 252 (20), 251 (100), 91 (79). HRMS (EI) calcd for C₃₀H₂₇N₃O₃ [M⁺]: 477.2052; found: 477.2068.

A solution of the N-benzyl derivative of 82 (79 mg, 0.17 mmol) in methanol (1.5 mL) was added to 10% palladium on charcoal (21 mg). The mixture was hydrogenated as in the preceding procedure for 48 h. The reaction was cooled to room temperature and filtered through Celite. The filtrate was concentrated under vacuum and the residue was purified by flash chromatography over silica gel (methanol-dichloromethane) to obtain 22 mg (34%) of 82 as a beige solid; mp 136–138 °C; IR (film) 3355, 3279, 3061, 2928, 2835, 1588, 1495, 1251, 745 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.05 (s, 1H), 7.97 (d, J = 7.7 Hz, 1H), 7.93 (d, J = 8.5 Hz, 1H), 7.75–7.65 (m, 2H), 7.43–7.32 (m, 3H), 7.27 (t, J = 7.2 Hz, 1H), 7.10 (t, J = 7.3 Hz, 1H), 6.96 (d, J = 2.0 Hz, 1H), 6.75 (dd, J = 8.5, 2.1 Hz, 1H), 5.07 (d, J = 4.2 Hz, 1H), 4.09–3.93 (m, 3H), 4.07 (s, 2H), 2.83 (dd, J = 12.0, 3.7 Hz, 1H), 2.75 (dd, J = 11.5, 5.6 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 165.8, 157.8, 150.2, 141.0, 140.7, 139.7, 124.9, 124.3, 124.1, 122.6, 120.8, 119.5, 119.2, 118.5, 116.2, 110.7, 110.5, 108.1, 70.9, 68.4, 51.9, 46.2; MS (EI) m/z (relative intensity) 387 (82) [M⁺], 183 (100), 161 (25), 133 (32), 132 (39). HRMS (EI) calcd for C₂₃H₂₁N₃O₃ [M⁺]: 387.1583; found: 387.1587.

Compounds 83–90 and 92 were prepared by the treatment of the corresponding epoxides 103a, 105, 114a, 117a or 117c with the appropriate amines, by means of the same procedure as for the preparation of 6, except for the variation described below for 84.

1-(9H-Carbazol-4-yloxy)-3-(3,4-dihydro-2H-1,4-benzoxazin-4-yl)-2-propanol (83)

From 103a and 118a.Yield: 67%; off-white solid; mp 68–70 °C; IR (film) 3398, 3056, 2930, 2870, 1605, 1502, 1452, 1343, 1097, 722 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.30 (d, J = 7.8 Hz, 1H), 8.08 (s, 1H), 7.47–7.37 (m, 2H), 7.33 (dd, J = 8.0, 7.9 Hz, 1H), 7.30–7.21 (m, 1H), 7.06 (d, J = 8.0 Hz, 1H), 6.90–6.79 (m, 3H), 6.75–6.61 (m, 2H), 4.57–4.45 (m, 1H), 4.40–4.24 (m, 2H), 4.21 (t, J = 4.4 Hz, 2H), 3.69 (dd, J = 14.8, 5.4 Hz, 1H), 3.57 (dd, J = 14.8, 7.1 Hz, 1H), 3.53–3.34 (m, 2H), 2.61 (s, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 154.9, 144.4, 141.1, 138.9, 135.4, 126.9, 125.3, 122.9, 122.5, 121.9, 119.9, 118.5, 116.8, 113.0, 112.8, 110.3, 104.3, 101.4, 69.8, 68.4, 64.4, 55.2, 49.0; MS (ESI) m/z (relative intensity) 375 (100) [M + H]⁺. HRMS (ESI) calcd for C₂₃H₂₃N₂O₃ [M + H]⁺: 375.1709; found: 375.1708.

Preparation of 4-[3-(9H-carbazol-4-yloxy)-2-hydroxypropyl]-3,4-dihydro-2H-1,4-benzoxazin-3-one (84)

A mixture of epoxide 103a (179 mg, 0.748 mmol), 118b (101 mg, 0.677 mmol), and Cs₂CO₃ (309 mg, 0.948 mmol) in DMF (2 mL) was heated at 80 °C for 20 h. The reaction was then partitioned between ethyl acetate and water. The organic phase was separated, washed with brine, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford 94 mg (36%) of 84; off-white solid; mp 133–135 °C; IR (film) 3402, 3342, 3050, 2925, 2870, 1663, 1497, 1094, 748, 720 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.25 (s, 1H), 8.30 (d, J = 7.8 Hz, 1H), 7.44 (d, J = 8.1 Hz, 1H), 7.41–7.47 (m, 1H), 7.33 (ddd, J = 8.8, 7.5, 1.5 Hz, 1H), 7.28 (dd, J = 8.0, 7.9 Hz, 1H), 7.10 (ddd, J = 8.0, 7.2, 1.0 Hz, 1H), 7.08 (dd, J = 8.0, 0.5 Hz, 1H), 6.97–7.03 (m, 3H), 6.66 (d, J = 7.6 Hz, 1H), 5.49 (d, J = 5.3 Hz, 1H), 4.67 (d, J = 14.8 Hz, 1H), 4.61 (d, J = 14.8 Hz, 1H), 4.32–4.40 (m, 1H), 4.09–4.31 (m, 4H); ¹³C NMR (101 MHz, DMSO-d₆) δ 164.3, 154.7, 145.0, 141.1, 138.9, 129.3, 126.4, 124.5, 123.4, 122.6, 122.4, 121.6, 118.5, 116.5, 116.1, 111.5, 110.3, 104.0, 100.4, 70.2, 67.1, 66.4, 44.5; MS (EI) m/z (relative intensity) 388 (25) [M⁺], 206 (100). HRMS (EI) calcd for C₂₃H₂₀N₂O₄ [M⁺]: 388.1423; found: 388.1417.

4-(9H-Carbazol-4-yloxy)-1-(3,4-dihydro-2H-1,4-benzoxazin-4-yl)-2-butanol (85)

From 105 and 118a.Yield: 20% (35% based on recovered starting material); off-white solid; mp 172–174 °C; IR (film) 3516, 3319, 2945, 2879, 1600, 1500, 1091, 734, 720 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.21 (s, 1H), 8.07 (d, J = 7.8 Hz, 1H), 7.42 (d, J = 8.1 Hz, 1H), 7.25–7.35 (m, 2H), 6.97–7.10 (m, 2H), 6.76 (dd, J = 8.1, 1.5 Hz, 1H), 6.62–6.73 (m, 3H), 6.48 (ddd, J = 7.9, 7.2, 1.5 Hz, 1H), 4.99 (d, J = 5.6 Hz, 1H), 4.06–4.40 (m, 5H), 3.52–3.58 (m, 1H), 3.37–3.43 (m, 2H), 3.22 (dd, J = 14.6, 7.5 Hz, 1H), 2.13–2.23 (m, 1H), 1.82–1.94 (m, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 155.0, 143.3, 141.0, 138.8, 135.4, 126.5, 124.4, 122.2, 121.7, 121.3, 118.5, 116.1, 115.7, 111.7, 111.4, 110.3, 103.7, 100.3, 64.6, 64.1, 63.9, 57.5, 48.3, 34.7; MS (EI) m/z (relative intensity) 388 (26%) [M⁺], 148 (100%). HRMS (EI) calcd for C₂₄H₂₄N₂O₃ [M⁺]: 388.1787; found: 388.1786.

1-(9H-Carbazol-3-yloxy)-3-(3,4-dihydro-2H-1,4-benzoxazin-4-yl)-2-propanol (86)

From 114a and 118a. Yield: 76%; white solid; mp 61–62 °C; IR (film) 3402, 3056, 2925, 2862, 1500, 1183, 745 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 8.01 (d, J = 7.8 Hz, 1H), 7.95 (s, 1H), 7.59 (d, J = 2.4 Hz, 1H), 7.38–7.44 (m, 2H), 7.35 (d, J = 8.7 Hz, 1H), 7.17–7.25 (m, 1H), 7.10 (dd, J = 8.7, 2.5 Hz, 1H), 6.76–6.87 (m, 3H), 6.66 (ddd, J = 8.1, 6.2, 2.4 Hz, 1H), 4.31–4.50 (m, 1H), 4.24 (t, J = 4.4 Hz, 2H), 4.07–4.22 (m, 2H), 3.59 (dd, J = 14.8, 5.6 Hz, 1H), 3.40–3.57 (m, 3H), 2.53 (d, J = 4.8 Hz, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 152.8, 144.4, 140.5, 135.5, 134.9, 126.1, 124.0, 123.3, 121.8, 120.4, 119.3, 118.3, 116.8, 115.5, 112.9, 111.5, 110.9, 104.9, 71.0, 68.5, 64.5, 54.8, 49.0; MS (EI) m/z (relative intensity) 374 (42) [M⁺], 148 (100); HRMS (EI+) m/z calcd for C₂₃H₂₂N₂O₃ [M⁺]: 374.1630; found: 374.1621.

1-(9H-Carbazol-2-yloxy)-3-(3,4-dihydro-2H-1,4-benzoxazin-4-yl)-2-propanol (87)

From 117a and 118a. Yield: 61%; beige solid; mp 172–174 °C; IR (film) 3402, 3053, 2930, 2870, 1602, 1502, 1097, 908, 725 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.08 (s, 1H), 7.98 (d, J = 8.0 Hz, 1H), 7.97 (d, J = 8.0 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.28 (ddd, J = 8.2, 7.2, 1.2 Hz, 1H), 7.18–7.05 (ddd, , J = 8.0, 7.0, 1.0 Hz, 1H), 6.99 (d, J = 2.1 Hz, 1H), 6.81 (dd, J = 8.5, 2.2 Hz, 1H), 6.76 (dd, J = 8.1, 1.5 Hz, 1H), 6.71 (ddd, J = 8.1, 7.1, 1.5 Hz, 1H), 6.65 (dd, J = 7.9, 1.5 Hz, 1H), 6.47 (ddd, J = 7.8, 7.2, 1.5 Hz, 1H), 5.26 (s, 1H), 4.23–4.08 (m, 3H), 4.04 (d, J = 5.1 Hz, 2H), 3.56 (dd, J = 14.7, 4.9 Hz, 1H), 3.53–3.40 (m, 2H), 3.28 (dd, J = 14.7, 6.8 Hz, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 157.7, 143.4, 141.0, 139.7, 135.4, 124.1, 122.6, 121.3, 120.9, 119.2, 118.5, 116.4, 116.3, 115.8, 111.9, 110.6, 108.1, 95.3, 70.4, 66.8, 63.9, 54.0, 48.2; MS (EI) m/z (relative intensity) 374 (40) [M⁺], 148 (100). HRMS (EI) calcd for C₂₃H₂₂N₂O₃ [M⁺]: 374.1630; found: 374.1613.

1-(3,4-Dihydro-2H-1,4-benzoxazin-4-yl)-3-(6-fluoro-9H-carbazol-2-yloxy)-2-propanol (88)

From 117c and 118a. Yield: 86%; white solid; mp 180–181 °C; IR (film) 3392, 2917, 2850, 1605, 1502, 1163, 911, 738 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.12 (s, 1H), 7.98 (d, J = 8.6 Hz, 1H), 7.82 (dd, J = 9.5, 2.6 Hz, 1H), 7.40 (dd, J = 8.8, 4.5 Hz, 1H), 7.11 (ddd, J = 9.5, 9.4, 2.6 Hz, 1H), 6.98 (d, J = 2.1 Hz, 1H), 6.82 (dd, J = 8.6, 2.2 Hz, 1H), 6.76 (dd, J = 8.1, 1.4 Hz, 1H), 6.70 (ddd, J = 8.1, 7.6, 1.5 Hz, 1H), 6.65 (dd, J = 7.8, 1.5 Hz, 1H), 6.47 (ddd, J = 7.9, 7.8, 1.5 Hz, 1H), 5.24 (d, J = 4.8 Hz, 1H), 4.23–4.07 (m, 3H), 4.04 (d, J = 4.9 Hz, 2H), 3.55 (dd, J = 14.7, 4.8 Hz, 1H), 3.54–3.46 (m, 1H), 3.44–3.35 (m, 1H), 3.35–3.23 (m, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 158.1, 156.5 (d, ¹J_{C F} = 231 Hz), 143.4, 142.1, 136.1, 135.4, 123.2 (d, ³J_{C F} = 10 Hz), 121.4, 121.3, 116.4, 116.1 (d, ⁴J_{C F} = 4.0 Hz), 115.8, 111.9, 111.5 (d, ²J_{C F} = 27 Hz), 111.3 (d, ³J_{C F} = 12 Hz), 108.3, 104.9 (d, ²J_{C F} = 24 Hz), 95.3, 70.4, 66.8, 63.8, 54.0, 48.2; ¹⁹F NMR (376 MHz, DMSO-d₆) δ −127.1; MS (EI) m/z (relative intensity) 392 (24%) [M⁺], 148 (100%). HRMS (EI) calcd for C₂₃H₂₁N₂O₃F [M⁺]: 392.1536; found: 392.1523.

1-(9H-Carbazol-4-yloxy)-3-[4-(2-methoxyphenyl)piperazin-1-yl]-2-propanol (89)

From 103a and 118c. Yield 87%; white solid; mp 88–89 °C; IR (film) 3406, 3273, 3060, 2943, 2828, 1502, 1240, 1098, 909, 751, 724 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J = 7.9 Hz, 1H), 8.12 (s, 1H), 7.42–7.37 (m, 2H), 7.33 (t, J = 8.0 Hz, 1H), 7.29–7.21 (m, 1H), 7.08–6.92 (m, 4H), 6.88 (dd, J = 8.0, 1.1 Hz, 1H), 6.70 (d, J = 7.8 Hz, 1H), 4.43–4.31 (m, 2H), 4.29–4.22 (m, 1H), 3.88 (s, 3H), 3.16 (br s, 4 H), 3.02–2.91 (m, 2H), 2.86–2.79 (m, 2H), 2.79–2.68 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 155.4, 152.4, 141.3, 141.1, 138.9, 126.8, 125.1, 123.2, 123.1, 122.7, 121.2, 119.8, 118.4, 112.9, 111.4, 110.1, 103.9, 101.4, 70.5, 65.9, 61.3, 55.5, 53.8, 50.9; MS (EI) m/z (relative intensity) 431 (25) [M⁺], 205 (100). HRMS (EI) calcd for C₂₆H₂₉N₃O₃ [M]⁺: 431.2209; found: 431.2220.

1-(9H-Carbazol-4-yloxy)-3-(4-phenylpiperazin-1-yl]-2-propanol (90)

From 103a and 118d. Yield: 97%; off-white solid; mp 75–77 °C; IR (film) 3405, 3295, 3056, 2940, 2824, 1598, 1505, 1449, 1094, 908, 752, 725 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.31 (d, J = 7.9 Hz, 1H), 8.08 (s, 1H), 7.44–7.37 (m, 2H), 7.37–7.22 (m, 4H), 7.05 (d, J = 7.9 Hz, 1H), 7.01–6.92 (m, 2H), 6.89 (dd, J = 7.3, 7.2 Hz, 1H), 6.70 (d, J = 7.9 Hz, 1H), 4.43–4.30 (m, 2H), 4.31–4.21 (m, 1H), 3.57 (br s, 1H), 3.34–3.18 (m, 4H), 2.97–2.86 (m, 2H), 2.86–2.74 (m, 2H), 2.75–2.64 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 155.3, 151.3, 141.1, 138.9, 129.3, 126.8, 125.2, 123.1, 122.7, 120.0, 119.8, 116.3, 112.9, 110.2, 104.0, 101.4, 70.4, 66.0, 61.2, 53.6, 49.4; MS (EI) m/z (relative intensity) 401 (30) [M⁺], 175 (100). HRMS (EI) calcd for C₂₅H₂₇N₃O₂ [M]⁺: 401.2103; found: 401.2114.

N-[3-(9H-Carbazol-4-yloxy)-2-hydroxypropyl]-2-(2-methoxyphenoxy)aniline (92)

From 103a and 118e. Yield: 88%; white solid; mp 62–64 °C; IR (film) 3407, 3059, 2930, 1603, 1497, 1261, 1208, 725 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.26 (d, J = 7.6 Hz, 1H), 8.08 (s, 1H), 7.46–7.36 (m, 2H), 7.32 (t, J = 8.0 Hz, 1H), 7.24 (ddd, J = 8.0, 6.5, 1.8 Hz, 1H), 7.12–7.05 (m, 2H), 7.04–6.98 (m, 1H), 6.99–6.91 (m, 3H), 6.88 (ddd, J = 8.0, 7.3, 1.5 Hz, 1H), 6.78 (dd, J = 8.0, 1.4 Hz, 1H), 6.72–6.66 (m, 1H), 6.64 (d, J = 8.0 Hz, 1H), 5.31 (br s, 1H), 4.53–4.43 (m, 1H), 4.31 (d, J = 5.2 Hz, 2H), 3.82 (s, 3H), 3.68 (dd, J = 13.4, 4.5 Hz, 1H), 3.53 (dd, J = 13.3, 7.3 Hz, 1H), 2.70 (s, 1H); ¹³C NMR (101 MHz, CDCl₃) δ 155.1, 150.9, 145.7, 144.9, 141.1, 139.4, 138.9, 126.8, 125.2, 124.4, 124.3, 123.0, 122.6, 121.2, 119.9, 119.7, 117.8, 117.7, 112.8, 112.2, 110.2, 104.2, 101.5, 70.1, 69.1, 56.1, 47.2; MS (EI) m/z (relative intensity) 454 (78) [M⁺], 228 (100), 183 (40), 120 (25). HRMS (EI) calcd for C₂₈H₂₆N₂O₄ [M⁺]: 454.1893; found: 454.1885.

Preparation of 2-(9H-carbazol-4-yloxy)-N-[2–2-(methoxyphenoxy)ethyl]acetamide (93)

A mixture of amine 104a (208 mg, 1.24 mmol) in dry THF (12 mL) was cooled in an ice bath and treated with Et₃N (0.34 mL, 2.4 mmol). After 15 min, acid 120⁵² (292 mg, 1.21 mmol), N-(3-diethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC hydrochloride) (356 mg, 1.86 mmol) and 1-hydroxybenzotriazole hydrate (HOBT·H₂O) (280 mg, 1.8 mmol) were added sequentially and the reaction mixture was stirred at room temperature for 3 h. It was partitioned between ethyl acetate and water, the organic phase was separated and washed with saturated aqueous NH₄Cl and NaHCO₃, H₂O, brine, dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford 318 mg (67%) of 93 as a white solid; mp 155–156 °C; IR (film) 3425, 3292, 3053, 2937, 2827, 1671, 1502, 1256, 752, 722 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.29 (s, 1H), 8.28 (t, J = 5.5 Hz, 1H), 8.22 (d, J = 7.8 Hz, 1H), 7.45 (d, J = 8.1 Hz, 1H), 7.33 (t, J = 8.0 Hz, 1H), 7.26 (t, J = 8.0 Hz, 1H), 7.10 (d, J = 7.9 Hz, 1H), 7.06 (t, J = 8.0 Hz, 1H), 6.82–7.02 (m, 4H), 6.61 (d, J = 7.9 Hz, 1H), 4.76 (s, 2H), 4.05 (t, J = 5.8 Hz, 2H), 3.70 (s, 3H), 3.57 (q, J = 5.7 Hz, 2H); ¹³C NMR (101 MHz, DMSO-d₆) δ 168.0, 154.0, 149.3, 147.8, 141.1, 138.9, 126.3, 124.6, 122.6, 121.4 (2C), 120.7, 118.5, 114.2, 112.4, 111.7, 110.3, 104.5, 100.8, 67.3, 67.2, 55.4, 38.2; MS (EI) m/z (relative intensity) 390 (64) [M⁺], 267 (100), 196 (42), 154 (57). HRMS (EI) calcd for C₂₃H₂₂N₂O₄ [M⁺]: 390.1580; found: 390.1577.

Preparation of 2-(9H-carbazol-4-yloxy)-N-[1-hydroxy-3-(2-methoxyphenoxy)propan-2-yl]acetamide (94)

A solution of 118f·HCl (354 mg, 1.51 mmol) in dry THF (20 mL) was cooled in an ice bath and treated with Et₃N (0.65 mL, 4.5 mmol). After 15 min, acid 120⁵² (365 mg, 1.51 mmol), EDC hydrochloride (435 mg, 2.26 mmol) and HOBT·H₂O (348 mg, 2.3 mmol) were added sequentially and the reaction mixture was stirred at room temperature for 4 h. It was worked up and purified as in the preceding procedure to afford 481 mg (76%) of 94 as a white solid; mp 169–170 °C; IR (film) 3412, 3285, 3056, 2933, 1661, 1502, 1253, 1216, 1107, 722 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.27 (s, 1H), 8.21 (d, J = 7.8 Hz, 1H), 7.97 (d, J = 8.1 Hz, 1H), 7.45 (d, J = 8.1 Hz, 1H), 7.32 (t, J = 7.2 Hz, 1H), 7.27 (t, J = 8.0 Hz, 1H), 7.11 (d, J = 8.0 Hz, 1H), 7.08–7.00 (m, 2H), 6.83–7.00 (m, 3H), 6.64 (d, J = 7.9 Hz, 1H), 4.99 (t, J = 5.4 Hz, 1H), 4.77 (s, 2H), 4.28–4.16 (m, 1H), 4.15–4.00 (m, 2H), 3.70 (s, 3H), 3.69–3.63 (m, 1H), 3.63–3.55 (m, 1H); ¹³C NMR (101 MHz, DMSO-d₆) δ 167.6, 153.89, 149.3, 148.0, 141.1, 138.9, 126.3, 124.6, 122.5, 121.4, 121.3, 120.7, 118.6, 114.1, 112.6, 111.5, 110.4, 104.5, 100.9, 67.3, 67.2, 59.8, 55.6, 50.1; MS (EI) m/z (relative intensity) 420 (40) [M⁺], 297 (100), 196 (42), 154 (44). HRMS (EI) calcd for C₂₄H₂₄N₂O₅ [M⁺]: 420.1685; found: 420.1667.

Preparation of 4-{[4-(2-methoxyphenoxymethyl)-4,5-dihydro-1,3-oxazol-2-yl]methoxy}-9H-carbazole (91)

A solution of 94 (75 mg, 0.18 mmol) in a 2:1 mixture of dichloromethane-THF (4 mL) was cooled to −78 °C and treated with diethylaminosulfur trifluoride⁴¹ (DAST) (32 μL, 0.24 mmol). After 1 h, K₂CO₃ (38 mg, 0.26 mmol) was added and the cold bath was removed. The reaction mixture was stirred at room temperature for 2 h., diluted with saturated aqueous NaHCO₃ solution and extracted with dichloromethane. The combined organic extracts were dried over Na₂SO₄ and concentrated under vacuum. The residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford 44 mg (62%) of 91 as a white solid; mp 152–154 °C; IR (film) 3402, 3062, 2936, 1669, 1606, 1583, 1500, 1452, 1252, 1117, 751, 722 cm^−1;1H NMR (400 MHz, DMSO-d₆) δ 11.28 (s, 1H), 8.22 (d, J = 7.8 Hz, 1H), 7.45 (d, J = 8.1 Hz, 1H), 7.34 (ddd, J = 8.2, 7.2, 1.2 Hz, 1H), 7.27 (t, J = 8.0 Hz, 1H), 7.10–7.15 (m, 1H), 7.11 (d, J = 7.7 Hz, 1H), 6.82–7.05 (m, 4H), 6.75 (d, J = 7.7 Hz, 1H), 5.02 (s, 2H), 4.43–4.62 (m, 2H), 4.27–4.35 (m, 1H), 4.09 (dd, J = 9.7, 4.4 Hz, 1H), 3.98 (dd, J = 9.7, 5.4 Hz, 1H), 3.75 (s, 3H); ¹³C NMR (101 MHz, DMSO-d₆) δ 163.8, 153.9, 149.3, 148.0, 141.1, 138.9, 126.3, 124.7, 122.5, 121.5, 121.4, 120.8, 118.6, 114.5, 112.7, 111, 110.4, 104.5, 100.8, 70.6, 69.9, 65.2, 62.3, 55.7; MS (EI) m/z (relative intensity) 402 (100) [M⁺], 182 (38), 154 (72). HRMS (EI) calcd for C₂₄H₂₂N₂O₄ [M⁺]: 402.1580; found: 402.1560.

Preparation of 1-(4,6-dibromo-9H-carbazol-3-yloxy)-3-{[2-(2-methoxyphenoxy)ethyl]amino}-2-propanol (97)

Compound 97 was obtained from 4,6-dibromo-3-hydroxycarbazole (96) by treatment with epichlorohydrin, followed by amine 104a by the same procedure as employed for the preparation of 3.³² Yield 42%; off-white solid; mp 141–143 °C; IR (KBr) 3458, 3378, 2922, 2834, 1507, 1452, 1253, 1222, 1186, 1121, 745 cm⁻¹; ¹H NMR (400 MHz, CDCl₃) δ 8.90 (d, J = 1.8 Hz, 1H), 8.22 (br s, 1H), 7.55 (dd, J = 8.6, 2.0 Hz, 1H), 7.31 (d, J = 8.7, 2.6 Hz, 1H), 7.30 (d, J = 8.7 Hz, 1H), 6.98–6.90 (m, 4H), 4.20–4.10 (m, 5H), 3.86 (s, 3H), 3.13 (dd, J = 5.8, 5.7 Hz, 2H), 2.99 (dd, J = 6.4, 4.7 Hz, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 149.9, 149.5, 148.4, 139.2, 136.3, 129.5, 125.5, 125.1, 121.8, 121.1, 115.2, 114.4, 112.1, 112.07, 112.02, 110.1, 110.0, 107.4, 74.1, 69.0, 68.6, 56.0, 51.7, 49.0; MS (CI) m/z (relative intensity) 566 (52) [M⁺ (⁸¹Br₂)], 564 (100) [M⁺ (⁸¹Br⁷⁹Br)], 562 (47) [M⁺ (⁷⁹Br₂)], 487 (40), 485 (41), 407 (18), 224 (36). HRMS (EI) m/z calcd for C₂₄H₂₄81Br⁷⁹BrN₂O₄ [M⁺]: 564.0082; found: 564.0099.

Preparation of 6-[(-(4,6-dibromo-9H-carbazol-3-yloxy)methyl]-4-[2-(2-methoxyphenoxy)ethyl]morpholin-3-one (98)

Compound 98 was prepared from 97 by the same procedure as employed for the preparation of 17. Yield 34%; white solid; mp 208–209 °C; IR (KBr) 3430, 3277, 2926, 2875, 1634, 1504, 1290, 1255, 751 cm⁻¹; ¹H NMR (400 MHz, DMSO-d₆) δ 11.63 (s, 1H), 8.72 (d, J = 2.0 Hz, 1H), 7.59 (dd, J = 8.6, 2.0 Hz, 1H), 7.51 (d, J = 8.8 Hz, 1H), 7.50 (d, J = 8.8 Hz, 1H), 7.36 (d, J = 8.8 Hz, 1H), 7.02–6.83 (m, 4H), 4.28–4.10 (m, 7H), 3.72 (s, 3H), 3.85–3.61 (m, 4H); ¹³C NMR (101 MHz, DMSO-d₆) δ 165.9, 149.2, 148.3, 147.7, 139.3, 136.5, 128.6, 123.6, 121.4, 120.7, 120.4, 115.6, 113.8, 113.2, 112.3, 111.0, 110.0, 105.5, 104.4, 71.6, 71.0, 66.9, 66.4, 55.5, 49.0, 45.6; MS (EI) m/z (relative intensity) 482 (39), 480 (100), 478 (44). HRMS (EI) calcd for C₂₆H₂₄81Br⁷⁹BrN₂O₅ [M⁺]: 604.0031; found: 604.0007.

Preparation of 7-methoxy-5-methyl-2,3,4,5-tetrahydro-1,5-benzothiazepine (101)

Thiapyrone 123⁴⁰ (1.00 g, 5.15 mmol) was dissolved in TFA (5 mL). Trimethylsilyl azide (0.68 mL, 5.2 mmol) was added at room temperature, the mixture was stirred for 2 d and the reaction was quenched with water and basified with NaOH. The mixture was extracted with dichloromethane, the combined organic phase was dried over Na₂SO₄, the solvent was evaporated under reduced pressure and the residue was purified by flash chromatography over silica gel (ethyl acetate-hexanes) to afford lactams 124⁵³ (260 mg, 24%) and 125⁵⁴ (500 mg, 47%). Product 125 had the following properties: ¹H NMR (300 MHz, CDCl₃) δ 8.25 (br s, 1H), 7.50 (d, J = 8.5 Hz, 1H), 6.73 (dd, J = 8.5, 2.6 Hz, 1H), 6.67 (d, J = 2.6 Hz, 1H), 3.82 (s, 3H), 3.39 (t, J = 7.0 Hz, 2H), 2.62 (t, J = 6.9 Hz, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 173.9, 161.0, 142.7, 136.4, 117.6, 112.1, 109.2, 55.6, 34.4, 33.6; MS (EI) m/z (relative intensity) 209 (100) [M⁺], 154 (75). HRMS (EI) calcd for C₁₀H₁₁NO₂S [M⁺]: 209.0511; found: 209.0507.

To lactam 125 (500 mg, 2.39 mmol) in dry THF-ether (15 mL, 1:1), LiAlH₄ (181 mg, 4.77 mmol) was added at 0 °C and the mixture was then heated at 40 °C overnight. The reaction was carefully quenched with 0.5 mL of water and filtered through Celite. The solid was washed repeatedly with ether, the filtrate was evaporated and the crude product was purified by flash chromatography over silica gel to give the corresponding amine (260 mg, 56%) as an oil that solidified upon standing: mp 71.5–72.5 °C; ¹H NMR (400 MHz, CDCl₃) δ 7.33 (d, J = 8.5 Hz, 1H), 6.41 (dd, J = 8.5, 2.6 Hz, 1H), 6.34 (d, J = 2.6 Hz, 1H), 3.76 (s, 3H), 3.24–3.22 (m, 2H), 2.76–2.73 (m, 2H), 2.12–2.06 (m, 2H); ¹³C NMR (101 MHz, CDCl₃) δ 159.8, 153.3, 134.1, 117.0, 106.6, 105.9, 55.3, 47.7, 33.5, 32.1; MS (EI) m/z (relative intensity) 195 (97) [M⁺], 166 (100). HRMS (EI) calcd for C₁₀H₁₃NOS [M⁺]: 195.0718; found: 195.0710.

The above amine (250 mg, 1.28 mmol) was dissolved in 10 mL of methanol and 1.1 mL of 37% formaldehyde. Sodium cyanoborohydride (476 mg, 7.57 mmol) was added at room temperature and the mixture was stirred for 30 min, during which the pH was maintained between 4 and 5 by the addition of a few drops of 1 N HCl solution. The solvent was removed under reduced pressure, the residue was dissolved in dichloromethane, washed with water and dried over Na₂SO₄. The solvent was evaporated and the residue was purified by flash chromatography over silica gel (ether-pentane) to afford 245 mg (91%) of 101; colorless oil; IR 2933, 2822, 1593, 1555, 1478, 1107, 1074, 1032 cm⁻¹; ¹H NMR (300 MHz, CDCl₃) δ 7.33 (d, J = 8.4 Hz, 1H), 6.50 (d, J = 2.6 Hz, 1H), 6.40 (dd, J = 8.4, 2.6 Hz, 1H), 3.78 (s, 3H), 3.17–3.13 (m, 2H), 2.91 (s, 3H), 2.78–2.74 (m, 2H), 2.07–2.00 (m, 2H); ¹³C NMR (75 MHz, CDCl₃) δ 159.9, 155.1, 133.7, 117.9, 105.3, 104.4, 55.6, 55.2, 42.6, 30.5, 30.3; MS (EI) m/z (relative intensity) 209 (77) [M⁺], 180 (100). HRMS (EI) calcd for C₁₁H₁₅NOS [M⁺]: 209.0874; found: 209.0875.

Bioassay: Single-cell Ca²⁺ imaging of HEK293 cells

Stable, inducible HEK293 cells expressing a CPVT-causing RyR2 mutant, R4496C, display robust spontaneous Ca²⁺ oscillations (SOICR), but parental HEK293 cells do not.^55,56 These RyR2-R4496C cells were used to assess the impact of carvedilol, carvedilol analogs, beta-blockers, and other compounds on SOICR. SOICR was measured using single-cell Ca²⁺ imaging and the fluorescent Ca²⁺ indicator dye fura-2/AM (Invitrogen) as described previously^55,56 Briefly, cells grown on glass coverslips for 18–22 hours after induction by 1 μg/ml tetracycline were loaded with 5 μM fura 2/AM in KRH (Krebs–Ringer–Hepes) buffer (125 mM NaCl, 5 mM KCl, 1.2mM KH₂PO₄, 6 mM glucose, 1.2 mM MgCl₂ and 25 mM Hepes, pH 7.4) plus 0.02% pluronic F-127 and 0.1 mg/ml BSA for 20 min at room temperature (23°C). The coverslips were then mounted in a perfusion chamber (Warner Instruments, Hamden, CT, U.S.A.) on an inverted microscope (Nikon TE2000-S). The Ca²⁺ concentration was then stepped to 0.5 mM for 5 min before increasing to 1 mM. The cells were continuously perfused with KRH buffer containing 1 mM CaCl₂ and different drugs for 8–10 min. Caffeine (10 mM) was applied at the end of each experiment to confirm the expression of active RyR2 channels. Time-lapse images (0.25 frame/s) were captured and analyzed with the Compix Simple PCI 6 software (Compix Inc., Sewickley, PA, USA). Fluorescence intensities were measured from regions of interest centered on individual cells. Only cells that responded to caffeine were used in analyses. All chemicals were obtained from Sigma (St. Louis, MO) unless otherwise specified.

Chart 1.

Structures of carvedilol and some of its analogs

Abbreviations Used

SOICR

store overload-induced calcium release

RyR

ryanodine receptor

DAD

delayed after-polarization

CPVT

catecholaminergic polymorphic ventricular tachycardia

EDC

N-(3-diethylaminopropyl)-N′-ethylcarbodiimide

HOBT·H₂O

1-hydroxybenzotriazole hydrate

DAST

diethylaminosulfur trifluoride

TBDPS

t-butyldiphenylsilyl