Crystal structure of N-isopropyl-N-(phen­yl)phenyl­glyoxyl­amide

The title compound, C₁₇H₁₇NO₂, was synthesized and its photoreactive properties in the crystalline state were investigated. A solid-state photoreaction did not occur because the reaction sites were too far apart in the mol­ecule.

Abstract

The title compound [systematic name: 2-oxo-N,2-diphenyl-N-(propan-2-yl)acetamide], C₁₇H₁₇NO₂, was synthesized and its photoreactive properties in the crystalline state were investigated. In the mol­ecule, the carbonyl group attached to the phenyl ring adopts an s-trans configuration with respect to the isopropyl group. Moreover, the distance between the C atom of the carbonyl group and the N-bound C atom of the isopropyl group is 3.845 (2) Å, which is much longer than 3.2 Å, the threshold for photoreactions to take place in the mol­ecule. As a result, the crystal did not photoreact upon UV light irradiation. In the crystal, the mol­ecules are linked via weak inter­molecular C—H⋯O hydrogen bonds, forming a layer structure parallel to the ab plane.

Chemical context  

An achiral mol­ecule of N,N-diiso­propyl­aryl­glyoxyl­amide 1a having two isopropyl groups crystallizes in the chiral space group P2₁2₁2₁ and is transformed to the optically active β-lactam derivative 2a upon UV light irradiation (Fig. 1 ▸; Toda et al., 1987 ▸, 1993 ▸; Sekine et al., 1989 ▸; Hashizume et al., 1995 ▸, 1996 ▸, 1998 ▸). Likewise, N-eth­yl-N-iso­propyl­phenyl­glyoxyl­amide 1b, having an ethyl group and an isopropyl group, forms a chiral crystal (P2₁2₁2₁), and its photoirradiation in the solid state yields the optically active β-lactam derivative 2b (Fig. 1 ▸; Toda et al., 1997 ▸). Therefore, we synthesized the title compound 1c having a phenyl group and an isopropyl group, and investigated whether an optically active β-lactam derivative could be obtained by photoreaction of its crystals. It was found that the photoreaction did not proceed in the solid state. In this paper, an explanation for the lack of photoreactivity is presented based on single crystal X-ray structural analysis.

Figure 1.

Photoreaction of N-isopropyl-phenyl­glyoxyl­amide derivatives.

Structural commentary  

In the mol­ecule of 1c, the carbonyl group (C7=O1) adopts an s-trans configuration with respect to the isopropyl group (Fig. 2 ▸), in contrast to 1a and 1b, which have s-cis configurations. The torsion angles C7—C8—N1—C15 and O1—C7—C8—O2 are −179.43 (13) and −112.09 (19)°, respectively, in 1c. The corresponding torsion angles are −5.1 (4) and 88.0 (4)°, respectively, in 1a, and −10.4 (3) and 90.7 (2)°, respectively, in 1b; in the case of 1a, which has two isopropyl groups, the torsion angle including the reacting carbon atom was calculated.

Figure 2.

The mol­ecular structure of the title compound 1c. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.

In order for the Norrish–Yang reaction to take place, the reacting atoms in the mol­ecular structure must be in close proximity. In the crystal structure of 1c, the distance between the γ-hydrogen atom H15 and the carbonyl oxygen atom O1 is 4.565 Å. This inter­atomic distance is much longer than the ideal value of up to about 2.7 Å, at which photoreaction can proceed in the crystal (Konieczny et al., 2018 ▸). Moreover, the distance between the reacting C7 and C15 carbon atoms is 3.845 (2) Å, which is outside the range of ideal values of up to about 3.2 Å. These inter­atomic distances in 1c are large enough to prevent the photoreaction from taking place. In contrast, the corresponding distances are 2.78 (4) and 2.871 (4) Å in 1a, and 2.81 (3) and 2.897 (3) Å in 1b. As those distances are close to the ideal values, the photoreaction could occur in the crystalline state.

Supra­molecular features  

In the crystal of 1c, the mol­ecules are linked by weak inter­molecular C—H⋯O inter­actions (C10—H10⋯O1ⁱ and C13—H13⋯O2ⁱⁱ; symmetry codes as in Table 1 ▸), forming a layer structure parallel to the ab plane (Fig. 3 ▸).

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10⋯O1i	0.95	2.32	3.2140 (18)	157
C13—H13⋯O2ii	0.95	2.48	3.2895 (18)	143

Symmetry codes: (i) ; (ii) .

Figure 3.

A packing diagram viewed along the c axis isfor the title compound 1c, showing C—H⋯O inter­actions as dotted blue lines.

Database survey  

A search of the Cambridge Structural Database (Version 5.39, last update August 2018; Groom et al., 2016 ▸) generates nine hits for compounds based on the N-iso­propyl­phenyl­glyoxyl­amide fragment shown in Fig. 1 ▸. These results include five structural analogues including an isopropyl group (JAGLAE; Sekine et al., 1989 ▸), a methacryloyl group (NUKSOB; Sakamoto et al., 1997 ▸), an ethyl group (POWMIX; Toda et al., 1997 ▸), a tigloyl group (WEPCID01; Sakamoto et al., 1997 ▸) and a 2-tert-butyl­phenyl group (QUPWEE; Jesuraj & Sivaguru, 2010 ▸). The last compound has a similar mol­ecular structure to that of 1c, with a corresponding torsion angle of 174.6 (1)°. Of the remaining compounds, three are co-crystals of N,N-diiso­prop­yl­aryl­glyoxyl­amide with other organic compounds (ZEDJOH and ZEDJUN; Hashizume et al., 1994 ▸; POWMET; Toda et al., 1997 ▸).

Synthesis and crystallization  

The title compound was prepared according to a reported method (Toda et al., 1987 ▸,1997 ▸; Sekine et al., 1989 ▸): chlorin­ation of the phenyl­glyoxylic acid with thionyl chloride followed by reaction with N-iso­propyl­aniline and tri­ethyl­amine. Thus, to an ice-cooled solution of N-iso­propyl­aniline (0.72 ml, 5 mmol) and tri­ethyl­amine (0.70 ml, 5 mmol) in dry diethyl ether (2 ml) was added a solution of benzoyl­formyl chloride (0.84 g, 5 mmol) in dry diethyl ether (2 ml), and the reaction mixture was stirred for 3 h in an ice bath. After filtration of tri­ethyl­ammonium chloride, the filtrate was washed with dilute HCl and aqueous NaHCO₃ and dried over MgSO₄. The crude product was recrystallized from benzene to give 1c as colourless prisms (0.5968 g, 22.4% yield, m.p. 397–401 K); IR (KBr): ν_max 1643 and 1681 cm⁻¹; ¹H NMR (CDCl₃): δ_H 1.21 (d, 6H, CHMe ₂), 5.10 (sep, 1H, N—CH), 7.07–7.80 (m, 10H, ArH). Single crystals of 1c suitable for X-ray diffraction were grown from a benzene solution.

Photoreaction in the solid state  

1c (51.3 mg, 0.21 mmol) was pulverized in a mortar and irradiated with a 400 W high pressure mercury lamp for 20 h. No reaction took place, as determined by TLC, IR and NMR spectroscopy.

Refinement  

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All H atoms were positioned in geometrically calculated positions (C—H = 0.95–0.98 Å) and refined using a riding model with U _iso(H) = 1.2U _eq(C) and 1.5U _eq(C-meth­yl).

Table 2. Experimental details.

Crystal data
Chemical formula	C17H17NO2
M r	267.31
Crystal system, space group	Monoclinic, P21/n
Temperature (K)	93
a, b, c (Å)	5.8354 (5), 16.5123 (14), 15.1330 (12)
β (°)	93.837 (2)
V (Å3)	1454.9 (2)
Z	4
Radiation type	Mo Kα
μ (mm−1)	0.08
Crystal size (mm)	0.25 × 0.18 × 0.14
Data collection
Diffractometer	Rigaku R-AXIS RAPID
Absorption correction	Multi-scan (ABSCOR; Higashi, 1995 ▸)
T min, T max	0.642, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	13857, 3316, 2572
R int	0.043
(sin θ/λ)max (Å−1)	0.648
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.054, 0.143, 1.13
No. of reflections	3316
No. of parameters	183
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.36, −0.21

Computer programs: RAPID-AUTO (Rigaku, 1998 ▸), SHELXT2014 (Sheldrick, 2015a ▸), SHELXL2018 (Sheldrick, 2015b ▸), Mercury (Macrae et al., 2006 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

CCDC reference: 1870320

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Crystal data

C17H17NO2	F(000) = 568
Mr = 267.31	Dx = 1.220 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71075 Å
a = 5.8354 (5) Å	Cell parameters from 13857 reflections
b = 16.5123 (14) Å	θ = 3.7–27.5°
c = 15.1330 (12) Å	µ = 0.08 mm−1
β = 93.837 (2)°	T = 93 K
V = 1454.9 (2) Å3	Block, colorless
Z = 4	0.25 × 0.18 × 0.14 mm

Data collection

Rigaku R-AXIS RAPID diffractometer	3316 independent reflections
Radiation source: rotating anode X-ray	2572 reflections with I > 2σ(I)
Detector resolution: 10.0 pixels mm-1	Rint = 0.043
ω–scan	θmax = 27.5°, θmin = 3.7°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −7→6
Tmin = 0.642, Tmax = 0.989	k = −21→21
13857 measured reflections	l = −19→19

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.054	H-atom parameters constrained
wR(F2) = 0.143	w = 1/[σ2(Fo2) + (0.0737P)2 + 0.1802P] where P = (Fo2 + 2Fc2)/3
S = 1.13	(Δ/σ)max < 0.001
3316 reflections	Δρmax = 0.36 e Å−3
183 parameters	Δρmin = −0.21 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.9019 (2)	0.43953 (8)	0.30276 (9)	0.0606 (4)
O2	0.6189 (3)	0.53493 (7)	0.14588 (8)	0.0580 (4)
N1	0.5441 (2)	0.40017 (7)	0.15732 (7)	0.0296 (3)
C1	0.7452 (3)	0.54690 (9)	0.42792 (9)	0.0349 (3)
H1	0.890380	0.521888	0.440442	0.042*
C2	0.6582 (3)	0.59840 (10)	0.48934 (10)	0.0419 (4)
H2	0.742860	0.608701	0.544010	0.050*
C3	0.4469 (3)	0.63490 (10)	0.47073 (11)	0.0444 (4)
H3	0.386515	0.670465	0.512701	0.053*
C4	0.3231 (3)	0.61973 (10)	0.39107 (11)	0.0416 (4)
H4	0.178359	0.645041	0.378623	0.050*
C5	0.4093 (2)	0.56796 (9)	0.32967 (9)	0.0324 (3)
H5	0.323566	0.557451	0.275295	0.039*
C6	0.6215 (2)	0.53134 (8)	0.34761 (9)	0.0270 (3)
C7	0.7246 (2)	0.47610 (8)	0.28442 (10)	0.0328 (3)
C8	0.6187 (3)	0.47218 (8)	0.18929 (10)	0.0341 (3)
C9	0.5209 (2)	0.33160 (7)	0.21501 (8)	0.0244 (3)
C10	0.3298 (2)	0.32551 (9)	0.26361 (9)	0.0306 (3)
H10	0.216281	0.366815	0.260071	0.037*
C11	0.3046 (3)	0.25880 (10)	0.31762 (9)	0.0424 (4)
H11	0.173330	0.254294	0.351177	0.051*
C12	0.4701 (3)	0.19876 (9)	0.32281 (10)	0.0463 (4)
H12	0.451759	0.152802	0.359426	0.056*
C13	0.6617 (3)	0.20564 (9)	0.27481 (11)	0.0444 (4)
H13	0.776465	0.164769	0.279285	0.053*
C14	0.6880 (2)	0.27157 (9)	0.22024 (10)	0.0345 (3)
H14	0.819139	0.275831	0.186591	0.041*
C15	0.4431 (3)	0.39643 (8)	0.06438 (9)	0.0357 (4)
H15	0.509044	0.442544	0.031566	0.043*
C16	0.1885 (4)	0.40866 (18)	0.06136 (13)	0.0788 (8)
H16A	0.128132	0.413824	−0.000383	0.118*
H16B	0.154033	0.458040	0.093861	0.118*
H16C	0.116587	0.362105	0.088643	0.118*
C17	0.5082 (4)	0.31954 (11)	0.01865 (11)	0.0496 (5)
H17A	0.454587	0.322180	−0.044054	0.074*
H17B	0.436796	0.273184	0.046472	0.074*
H17C	0.675558	0.313261	0.023782	0.074*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0388 (7)	0.0666 (9)	0.0745 (9)	0.0178 (6)	−0.0104 (6)	−0.0379 (7)
O2	0.1117 (11)	0.0272 (6)	0.0356 (6)	−0.0214 (6)	0.0097 (7)	−0.0026 (5)
N1	0.0430 (7)	0.0230 (6)	0.0231 (5)	−0.0042 (5)	0.0039 (5)	−0.0016 (4)
C1	0.0364 (8)	0.0353 (7)	0.0318 (7)	0.0036 (6)	−0.0059 (6)	−0.0020 (6)
C2	0.0518 (9)	0.0446 (9)	0.0286 (7)	0.0014 (7)	−0.0024 (7)	−0.0067 (6)
C3	0.0558 (10)	0.0418 (9)	0.0365 (8)	0.0068 (7)	0.0099 (7)	−0.0095 (7)
C4	0.0378 (8)	0.0411 (8)	0.0458 (9)	0.0109 (6)	0.0025 (7)	−0.0034 (7)
C5	0.0344 (7)	0.0327 (7)	0.0294 (7)	0.0003 (6)	−0.0029 (6)	0.0005 (5)
C6	0.0313 (7)	0.0229 (6)	0.0267 (6)	−0.0019 (5)	0.0017 (6)	0.0001 (5)
C7	0.0318 (7)	0.0289 (7)	0.0379 (8)	−0.0024 (5)	0.0025 (6)	−0.0080 (6)
C8	0.0470 (9)	0.0261 (7)	0.0301 (7)	−0.0068 (6)	0.0103 (6)	−0.0050 (5)
C9	0.0296 (7)	0.0215 (6)	0.0216 (6)	−0.0004 (5)	−0.0011 (5)	−0.0024 (5)
C10	0.0318 (7)	0.0350 (7)	0.0250 (6)	0.0047 (5)	0.0023 (6)	0.0006 (5)
C11	0.0506 (9)	0.0487 (9)	0.0283 (7)	−0.0114 (7)	0.0058 (7)	0.0063 (7)
C12	0.0755 (12)	0.0301 (8)	0.0312 (8)	−0.0093 (7)	−0.0121 (8)	0.0097 (6)
C13	0.0600 (11)	0.0278 (7)	0.0427 (8)	0.0139 (7)	−0.0162 (8)	−0.0033 (6)
C14	0.0325 (7)	0.0347 (7)	0.0359 (7)	0.0066 (6)	−0.0003 (6)	−0.0067 (6)
C15	0.0603 (10)	0.0256 (7)	0.0211 (6)	−0.0041 (6)	0.0022 (6)	0.0004 (5)
C16	0.0715 (14)	0.128 (2)	0.0338 (9)	0.0442 (14)	−0.0149 (9)	−0.0091 (11)
C17	0.0712 (12)	0.0450 (9)	0.0318 (8)	0.0037 (8)	−0.0030 (8)	−0.0123 (7)

Geometric parameters (Å, º)

O1—C7	1.2141 (18)	C9—C14	1.3890 (18)
O2—C8	1.2269 (18)	C10—C11	1.385 (2)
N1—C8	1.3451 (17)	C10—H10	0.9500
N1—C9	1.4417 (16)	C11—C12	1.382 (2)
N1—C15	1.4893 (17)	C11—H11	0.9500
C1—C2	1.381 (2)	C12—C13	1.378 (3)
C1—C6	1.3952 (19)	C12—H12	0.9500
C1—H1	0.9500	C13—C14	1.381 (2)
C2—C3	1.385 (2)	C13—H13	0.9500
C2—H2	0.9500	C14—H14	0.9500
C3—C4	1.386 (2)	C15—C16	1.497 (3)
C3—H3	0.9500	C15—C17	1.507 (2)
C4—C5	1.382 (2)	C15—H15	1.0000
C4—H4	0.9500	C16—H16A	0.9800
C5—C6	1.3883 (19)	C16—H16B	0.9800
C5—H5	0.9500	C16—H16C	0.9800
C6—C7	1.4781 (19)	C17—H17A	0.9800
C7—C8	1.529 (2)	C17—H17B	0.9800
C9—C10	1.3796 (19)	C17—H17C	0.9800
C8—N1—C9	121.17 (11)	C11—C10—H10	120.2
C8—N1—C15	118.33 (11)	C12—C11—C10	120.15 (15)
C9—N1—C15	119.47 (10)	C12—C11—H11	119.9
C2—C1—C6	120.50 (14)	C10—C11—H11	119.9
C2—C1—H1	119.8	C13—C12—C11	119.95 (14)
C6—C1—H1	119.8	C13—C12—H12	120.0
C1—C2—C3	119.57 (14)	C11—C12—H12	120.0
C1—C2—H2	120.2	C12—C13—C14	120.43 (14)
C3—C2—H2	120.2	C12—C13—H13	119.8
C2—C3—C4	120.23 (14)	C14—C13—H13	119.8
C2—C3—H3	119.9	C13—C14—C9	119.41 (14)
C4—C3—H3	119.9	C13—C14—H14	120.3
C5—C4—C3	120.31 (14)	C9—C14—H14	120.3
C5—C4—H4	119.8	N1—C15—C16	110.62 (13)
C3—C4—H4	119.8	N1—C15—C17	111.89 (12)
C4—C5—C6	119.86 (13)	C16—C15—C17	112.32 (16)
C4—C5—H5	120.1	N1—C15—H15	107.2
C6—C5—H5	120.1	C16—C15—H15	107.2
C5—C6—C1	119.53 (13)	C17—C15—H15	107.2
C5—C6—C7	122.58 (12)	C15—C16—H16A	109.5
C1—C6—C7	117.90 (12)	C15—C16—H16B	109.5
O1—C7—C6	122.44 (13)	H16A—C16—H16B	109.5
O1—C7—C8	118.59 (13)	C15—C16—H16C	109.5
C6—C7—C8	118.61 (12)	H16A—C16—H16C	109.5
O2—C8—N1	124.45 (13)	H16B—C16—H16C	109.5
O2—C8—C7	116.97 (12)	C15—C17—H17A	109.5
N1—C8—C7	118.47 (12)	C15—C17—H17B	109.5
C10—C9—C14	120.44 (13)	H17A—C17—H17B	109.5
C10—C9—N1	119.48 (11)	C15—C17—H17C	109.5
C14—C9—N1	120.07 (12)	H17A—C17—H17C	109.5
C9—C10—C11	119.61 (13)	H17B—C17—H17C	109.5
C9—C10—H10	120.2
C6—C1—C2—C3	−0.2 (2)	O1—C7—C8—N1	64.3 (2)
C1—C2—C3—C4	0.2 (3)	C6—C7—C8—N1	−122.42 (15)
C2—C3—C4—C5	0.1 (3)	C8—N1—C9—C10	80.08 (17)
C3—C4—C5—C6	−0.4 (2)	C15—N1—C9—C10	−88.16 (15)
C4—C5—C6—C1	0.4 (2)	C8—N1—C9—C14	−101.03 (16)
C4—C5—C6—C7	−179.31 (14)	C15—N1—C9—C14	90.73 (16)
C2—C1—C6—C5	−0.1 (2)	C14—C9—C10—C11	−0.3 (2)
C2—C1—C6—C7	179.61 (14)	N1—C9—C10—C11	178.59 (12)
C5—C6—C7—O1	−174.46 (15)	C9—C10—C11—C12	0.1 (2)
C1—C6—C7—O1	5.9 (2)	C10—C11—C12—C13	0.6 (2)
C5—C6—C7—C8	12.5 (2)	C11—C12—C13—C14	−1.1 (2)
C1—C6—C7—C8	−167.15 (13)	C12—C13—C14—C9	0.9 (2)
C9—N1—C8—O2	−171.72 (15)	C10—C9—C14—C13	−0.2 (2)
C15—N1—C8—O2	−3.3 (2)	N1—C9—C14—C13	−179.05 (12)
C9—N1—C8—C7	12.2 (2)	C8—N1—C15—C16	−91.50 (19)
C15—N1—C8—C7	−179.43 (13)	C9—N1—C15—C16	77.08 (19)
O1—C7—C8—O2	−112.09 (19)	C8—N1—C15—C17	142.45 (15)
C6—C7—C8—O2	61.20 (19)	C9—N1—C15—C17	−48.97 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10···O1i	0.95	2.32	3.2140 (18)	157
C13—H13···O2ii	0.95	2.48	3.2895 (18)	143

Symmetry codes: (i) x−1, y, z; (ii) −x+3/2, y−1/2, −z+1/2.

Funding Statement

This work was funded by Japan Society for the Promotion of Science grants JP17K05745 and JP18H04504.