4-Chloro­benzoyl-meso-octa­methyl­calix[2]pyrrolidino[2]pyrrole: an acyl chloride derivative of a partially reduced calix[4] pyrrole

Guillaume Journot; Reinhard Neier; Helen Stoeckli-Evans

doi:10.1107/S1600536812007003

. 2012 Mar 7;68(Pt 4):o976–o977. doi: 10.1107/S1600536812007003

4-Chlorobenzoyl-meso-octamethylcalix[2]pyrrolidino[2]pyrrole: an acyl chloride derivative of a partially reduced calix[4] pyrrole

Guillaume Journot ^a, Reinhard Neier ^a,^*, Helen Stoeckli-Evans ^b,^*

PMCID: PMC3343950 PMID: 22590031

Abstract

In the title compound, C₃₅H₄₇ClN₄O, the two pyrrolidine rings have envelope conformations. The conformation of the macrocycle is stabilized by N—H⋯N hydrogen bonds and a C—H⋯N interaction. The benzoyl ring is inclined to the adjacent pyrrole ring by 11.66 (11)°, with a centroid–centroid distance of 3.7488 (13) Å. In the crystal, molecules are linked by N—H⋯O hydrogen bonds into helical chains propagating in [010] and C—H⋯O and C—H⋯π interactions are also observed.

Related literature

For the heterogeneous catalytic hydrogenation of meso-octamethylcalix[4]pyrrole, which gave meso-octamethylcalix[2]pyrrole[2]pyrrolidine, see: Blangy et al. (2009 ▶). For N-acylation of pyrrolidines, using substituted benzoyl chlorides, see: Journot et al. (2012a ▶); Zhang et al. (2009 ▶). For the synthesis and reactivity of the title compound, see: Journot & Neier (2012 ▶). For the crystal structures of similar compounds, see: Journot et al. (2012b ▶,c ▶,d ▶,e ▶).

Experimental

Crystal data

C₃₅H₄₇ClN₄O
M _r = 575.22
Monoclinic,
a = 10.3224 (6) Å
b = 12.0389 (4) Å
c = 25.3311 (13) Å
β = 96.798 (4)°
V = 3125.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.16 mm⁻¹
T = 173 K
0.45 × 0.42 × 0.40 mm

Data collection

Stoe IPDS 2 diffractometer
Absorption correction: multi-scan (MULscanABS in PLATON; Spek, 2009 ▶) T _min = 0.973, T _max = 1.000
32665 measured reflections
5906 independent reflections
4215 reflections with I > 2σ(I)
R _int = 0.076

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.102
S = 1.03
5906 reflections
381 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2009 ▶); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2009 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97, PLATON and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812007003/zq2154sup1.cif

e-68-0o976-sup1.cif^{(42.4KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812007003/zq2154Isup2.hkl

e-68-0o976-Isup2.hkl^{(289.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812007003/zq2154Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of pyrrole ring N2/C3/C4/C25/C26; Cg2 is the centroid of the benzene ring C30–C35.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯N3	0.88	2.31	2.865 (2)	121
N4—H4⋯N3	0.88	2.55	3.051 (2)	117
C15—H15A⋯N2	0.98	2.52	3.488 (3)	171
C15—H15A⋯Cg1	0.98	2.40	3.301 (2)	152
N3—H3N⋯O1ⁱ	0.882 (18)	2.257 (18)	3.105 (2)	161.1 (18)
C23—H23B⋯O1ⁱ	0.98	2.53	3.495 (3)	168
C27—H27C⋯Cg2ⁱ	0.98	2.82	3.702 (2)	150

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Symmetry code: (i) Inline graphic .

Acknowledgments

HSE thanks the staff of the XRD Application Laboratory, CSEM, Neuchâtel for access to the X-ray diffraction equipment.

supplementary crystallographic information

Comment

We have recently reported the access to new macrocycles by heterogeneous catalytic hydrogenation of meso-octamethylcalix[4]pyrrole, which gave meso-octamethylcalix[2]pyrrole[2]pyrrolidine (1 in Fig. 3) [Blangy et al., 2009]. It was decided to investigate the nucleophilicity of this new macrocycle, which showed interesting reactivity (Journot & Neier, 2012), by reacting different substituted benzoyl chlorides with the macrocycle under smooth conditions [Journot et al., 2012a; Zhang et al., 2009]. Herein, we report on the synthesis and crystal structure of the title 4-chlorobenzoyl derivative, one of five compounds that have been studied by X-ray diffraction analysis (Journot et al., 2012b,c,d,e).

The molecular structure of the title compound is given in Fig. 1. The two pyrrolidine rings (N1,C1,C12—C14) and (N3,C6,C7,C21,C22) have envelope conformations with, respectively, atoms C13 and C6 as the flaps. The conformation of the macrocycle is stabilized by intramolecular N—H···N hydrogen bonds involving atom N3 and the two pyrrole H atoms, H2 and H4 (Fig. 1 and Table 1). The benzoyl ring (C30—C35) is inclined to the pyrrole ring (N4,C9,C10,C17,C18) by 11.66 (11)°, with a centroid-to-centroid distance of 3.7488 (13) Å. The methyl group C15 is also in close contact with the pyrrole ring (N2,C3,C4,C25,C26), with a short C15—H15A···N2 interaction and a C15—H15A···centroid distance of 3.301 (2) [see Table 1].

In the crystal, molecules are linked via an N—H···O hydrogen bond, involving the N3 pyrrolidine H-atom (H3N) and the benzoyl O atom (O1), leading to the formation of helical chains propagating along [010] - see Fig. 2 and Table 1. The same O atom is involved in a C—H···O contact with methyl group C23. A C—H···π interaction is also observed, involving the methyl group C27 and the benzoyl ring (C30—C35) [see Table 1].

The overall geometry and crystal packing is very similar to that reported for the 4-methoxybenzoyl derivative (Journot et al., 2012b), and the 4-nitrobenzoyl (Journot et al., 2012d) and 4-methylbenzoyl (Journot et al., 2012e) derivatives. The benzoyl derivative (Journot et al., 2012c) crystallized, in the trigonal space group R-3, as a partial (0.25H₂O) hydrate, and forms hydrogen bonded chains propagating along [001].

Footnote to Table 1: Cg1 is the centroid of pyrrole ring (N2,C3,C4,C25,C26); Cg2 is the centroid of the benzene ring (C30—C35).

Experimental

The general procedure for the N-acylation of meso-octamethylcalix[2]pyrrolidino[2]pyrrole (1) is illustrated in Fig. 3. A two-necked flask fitted with a gas inlet and containing a stirrer bar was charged with 100 mg (0.23 mmol) of meso-octamethylcalix[2]pyrrolidino[2]pyrrole (1), 4-chlorobenzoyl chloride (2c) (53.61 µL, 0.48 mmol), potassium carbonate (70 mg, 0.48 mmol) in THF (5 ml) and acetonitrile (2.5 ml). The reaction vessel was flushed with argon and sealed with a septum. After 15 min. a precipitate appeared and the reaction mixture was stirred for 2 h room temperature. 10% sodium carbonate was then added and the reaction mixture was extracted with dichloromethane. The organic layer was washed successively with two × 10% sodium carbonate and saturated brine. The organic layer was dried with sodium sulfate, and the solvents were removed under vacuum. The residue was purified by column chromatography (SiO₂, CH₂Cl₂/MeOH, 97/3) to yield 131.6 mg (75.6%) of colourless crystals of the title compound (3c). Melting point: 501 K. HRMS calcd. for C₃₅H₄₇ClN₄O⁺H⁺ 575.3511; found 575.3510. Further synthetic and spectroscopic data have been reported elsewhere (Journot & Neier, 2012).