organic compounds
(3R,4S)-3,4-Isopropylidenedioxy-5-phenylsulfonylmethyl-3,4-dihydro-2H-pyrrole 1-oxide
aDepartamento de Quimica Organica, Universidad de Salamanca, Plaza de los Caidos, 37008-Salamanca. Spain, and bServicio General de Rayos X, Universidad de Salamanca, Plaza de los Caidos, 37008-Salamanca. Spain
*Correspondence e-mail: ddm@usal.es
The title compound, C14H17NO5S, was prepared by oxidation of (2R,3S,4R)-2-phenylsulfonylmethyl-1-hydroxy-3,4-isopropylidenedioxypyrrolidine. Its confirms unequivocally its configuration. Two intermolecular C—H⋯O interactions help to establish the packing.
Related literature
For the preparation, see: Flores et al. (2010). For the standard oxidation of hydroxylamines to nitrones with manganese dioxide, see: Cicchi et al. (2001). For background to organocatalysts, see: Berkessel & Groger (2005); Macmillan (2008). For analogues of the organocatalyst L-proline, see: Andrey et al. (2004); Cobb et al. (2004); Tanaka et al. (2004); Wang et al. (2005).
Experimental
Crystal data
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Data collection: APEX2 (Bruker 2006); cell SAINT (Bruker 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
Supporting information
10.1107/S1600536811010737/bt5495sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811010737/bt5495Isup2.hkl
The title N-oxide, (II), was obtained by spontaneous oxidation of (2R,3S,4R)-2-Phenylsulfonylmethyl-1-hydroxy-3,4-isopropylidenedioxypyrrolidine (I) (Flores et al. 2010) in a 30% of yield. Our attention was then turned to the synthesis of this nitrone because of the important role α]D20 = +110.7 (c = 1.17, CHCl3). IR (film): 3376 (broad), 3058, 2995, 2967, 1580 cm-1. 1H NMR (200 MHz, CDCl3, δ p.p.m.): 7.94 (2H, m, Horto), 7.69–7.58 (3H, m, Hmeta Hpara), 5.58 (1H, d, J = 6.2 Hz, H-4), 4.87 (1H, t, J = 6.2 and 12 Hz H-3), 4.04 (2H, d, J = 4.4 Hz, H-2), 3.96 (2H, s, 2H-1) 1.38 (3H, s, Me-acetonide), 1.37 (3H, s, Me-acetonide). 13C NMR (50 MHz, CDCl3, δ p.p.m.): 139.7 (C—Ar), 134.62 (CH-para), 134.0 (C-5), 129.6 (2CH-meta), 128.1 (2CH-orto), 112.6 (C-acetonide), 80.8 (CH-4), 71.7 (CH-3), 68.1 (CH2–2), 52.1 (CH2–1), 27.2 (Me-acetonide), 25.8 (Me-acetonide). HRMS (EI): C14H17NO5S requires (M+Na)+, 334.0725, found 334.0703.
play in organic syntheses, particularly in the field of nitrogen containing natural products or bioactive analogues. Taking this into account we tried the standard oxidation of to with manganese dioxide according to the methodology described by Cicchi et al. (2001). MnO2 (107.2 mg, 1.11 mmol) was added to a solution of hydroxylamine I (234 mg, 0.74 mmol) in DCM (1.5 ml) at 0° C. The resulting mixture was stirred for 2 h, then it was filtered through celite; and concentrated. The resulting crude residue was purified by flash (silica gel, hexane/ EtAcO 1:1) to obtain the nitrone II (229 mg, 98%) (Flores et al., 2010). Well shaped colourless single crystals were obtained by crystallization from EtOAc/Et2O. [The hydrogen atoms were positioned geometrically with C—H distances constrained to 0.93 Å (aromatic CH), 0.96 Å (methyl groups), 0.97 Å (methylene groups) and refined using a riding mode with Uiso(H) = xUeq(C), where x = 1.5 for methyl H atoms and x = 1.2 for all other atoms.
Data collection: APEX2 (Bruker 2006); cell
SAINT (Bruker 2006); data reduction: SAINT (Bruker 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C14H17NO5S | F(000) = 656 |
Mr = 311.35 | Dx = 1.393 Mg m−3 |
Orthorhombic, P212121 | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 1922 reflections |
a = 5.6424 (2) Å | θ = 3.9–55.3° |
b = 15.5592 (7) Å | µ = 2.14 mm−1 |
c = 16.9097 (8) Å | T = 298 K |
V = 1484.52 (11) Å3 | Prismatic, colourless |
Z = 4 | 0.10 × 0.08 × 0.06 mm |
Bruker APEXII CCD area-detector diffractometer | 2487 independent reflections |
Radiation source: fine-focus sealed tube | 2159 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
phi and ω scans | θmax = 67.5°, θmin = 3.9° |
Absorption correction: multi-scan (SADABS; Bruker, 2006) | h = −6→5 |
Tmin = 0.815, Tmax = 0.880 | k = −18→15 |
8018 measured reflections | l = −18→19 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.034 | H-atom parameters constrained |
wR(F2) = 0.084 | w = 1/[σ2(Fo2) + (0.0335P)2 + 0.1514P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max < 0.001 |
2487 reflections | Δρmax = 0.14 e Å−3 |
192 parameters | Δρmin = −0.15 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 907 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.06 (2) |
C14H17NO5S | V = 1484.52 (11) Å3 |
Mr = 311.35 | Z = 4 |
Orthorhombic, P212121 | Cu Kα radiation |
a = 5.6424 (2) Å | µ = 2.14 mm−1 |
b = 15.5592 (7) Å | T = 298 K |
c = 16.9097 (8) Å | 0.10 × 0.08 × 0.06 mm |
Bruker APEXII CCD area-detector diffractometer | 2487 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2006) | 2159 reflections with I > 2σ(I) |
Tmin = 0.815, Tmax = 0.880 | Rint = 0.030 |
8018 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | H-atom parameters constrained |
wR(F2) = 0.084 | Δρmax = 0.14 e Å−3 |
S = 1.06 | Δρmin = −0.15 e Å−3 |
2487 reflections | Absolute structure: Flack (1983), 907 Friedel pairs |
192 parameters | Absolute structure parameter: 0.06 (2) |
0 restraints |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.89076 (11) | 0.02630 (4) | 0.36234 (4) | 0.05643 (18) | |
O1 | 0.8060 (3) | 0.16596 (13) | 0.57625 (11) | 0.0614 (5) | |
O2 | 0.9722 (5) | 0.10911 (14) | 0.68680 (13) | 0.0894 (7) | |
O3 | 1.3072 (4) | −0.05736 (13) | 0.53437 (13) | 0.0813 (6) | |
O4 | 0.9927 (4) | 0.05353 (13) | 0.28901 (11) | 0.0739 (6) | |
O5 | 0.6496 (3) | 0.04808 (13) | 0.37996 (14) | 0.0738 (6) | |
N1 | 1.1197 (4) | −0.01709 (14) | 0.55737 (13) | 0.0619 (6) | |
C1 | 0.8010 (4) | 0.07555 (18) | 0.56728 (16) | 0.0587 (7) | |
H1 | 0.6470 | 0.0557 | 0.5477 | 0.070* | |
C2 | 0.9998 (4) | 0.04067 (16) | 0.51895 (15) | 0.0521 (6) | |
C3 | 1.0217 (6) | −0.03387 (19) | 0.63738 (19) | 0.0805 (8) | |
H3A | 1.1460 | −0.0341 | 0.6770 | 0.097* | |
H3B | 0.9384 | −0.0884 | 0.6390 | 0.097* | |
C4 | 0.8538 (5) | 0.0402 (2) | 0.64986 (17) | 0.0729 (8) | |
H4 | 0.7099 | 0.0231 | 0.6782 | 0.088* | |
C5 | 0.9533 (4) | 0.18574 (16) | 0.64286 (17) | 0.0549 (6) | |
C6 | 1.1963 (5) | 0.2119 (3) | 0.6143 (2) | 0.0922 (11) | |
H6A | 1.2918 | 0.2289 | 0.6586 | 0.138* | |
H6B | 1.1819 | 0.2592 | 0.5782 | 0.138* | |
H6C | 1.2698 | 0.1642 | 0.5878 | 0.138* | |
C7 | 0.8367 (6) | 0.2541 (2) | 0.6910 (2) | 0.0864 (10) | |
H7A | 0.6857 | 0.2338 | 0.7094 | 0.130* | |
H7B | 0.8143 | 0.3045 | 0.6591 | 0.130* | |
H7C | 0.9351 | 0.2680 | 0.7355 | 0.130* | |
C8 | 1.0714 (4) | 0.06909 (17) | 0.43949 (14) | 0.0520 (6) | |
H8A | 1.2345 | 0.0520 | 0.4304 | 0.062* | |
H8B | 1.0648 | 0.1313 | 0.4374 | 0.062* | |
C9 | 0.9226 (4) | −0.08537 (16) | 0.37208 (15) | 0.0523 (6) | |
C10 | 1.1198 (5) | −0.12509 (19) | 0.33956 (16) | 0.0653 (7) | |
H10 | 1.2338 | −0.0933 | 0.3127 | 0.078* | |
C11 | 1.1429 (5) | −0.2125 (2) | 0.3480 (2) | 0.0754 (9) | |
H11 | 1.2732 | −0.2400 | 0.3257 | 0.090* | |
C12 | 0.9786 (6) | −0.26022 (19) | 0.38851 (18) | 0.0705 (8) | |
H12 | 0.9981 | −0.3193 | 0.3941 | 0.085* | |
C13 | 0.7836 (5) | −0.21963 (19) | 0.42093 (19) | 0.0703 (8) | |
H13 | 0.6707 | −0.2516 | 0.4481 | 0.084* | |
C14 | 0.7551 (4) | −0.13237 (18) | 0.41327 (17) | 0.0609 (7) | |
H14 | 0.6245 | −0.1051 | 0.4356 | 0.073* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0530 (3) | 0.0692 (4) | 0.0471 (3) | −0.0058 (3) | −0.0062 (3) | 0.0034 (3) |
O1 | 0.0476 (9) | 0.0863 (13) | 0.0503 (11) | 0.0057 (8) | −0.0094 (9) | 0.0002 (9) |
O2 | 0.1365 (19) | 0.0753 (12) | 0.0565 (12) | −0.0047 (13) | −0.0356 (13) | 0.0064 (10) |
O3 | 0.0906 (14) | 0.0759 (13) | 0.0774 (15) | 0.0194 (11) | 0.0000 (12) | 0.0008 (11) |
O4 | 0.0948 (13) | 0.0849 (13) | 0.0421 (11) | −0.0213 (11) | −0.0065 (11) | 0.0110 (9) |
O5 | 0.0455 (9) | 0.0819 (13) | 0.0939 (16) | 0.0066 (8) | −0.0109 (10) | −0.0017 (11) |
N1 | 0.0731 (13) | 0.0599 (12) | 0.0528 (13) | −0.0067 (12) | 0.0011 (13) | 0.0040 (11) |
C1 | 0.0440 (13) | 0.0819 (18) | 0.0503 (16) | −0.0131 (12) | 0.0022 (12) | −0.0013 (14) |
C2 | 0.0494 (12) | 0.0638 (15) | 0.0431 (13) | −0.0127 (12) | −0.0020 (12) | 0.0028 (12) |
C3 | 0.116 (2) | 0.0678 (17) | 0.0573 (17) | −0.0182 (17) | 0.0092 (19) | 0.0161 (16) |
C4 | 0.0835 (18) | 0.087 (2) | 0.0485 (15) | −0.0228 (16) | 0.0111 (16) | 0.0062 (15) |
C5 | 0.0470 (12) | 0.0704 (15) | 0.0471 (14) | 0.0057 (11) | −0.0093 (13) | 0.0006 (13) |
C6 | 0.0543 (16) | 0.135 (3) | 0.087 (3) | −0.0178 (17) | −0.0027 (17) | −0.017 (2) |
C7 | 0.077 (2) | 0.117 (3) | 0.065 (2) | 0.0361 (18) | −0.0159 (17) | −0.0214 (19) |
C8 | 0.0454 (13) | 0.0655 (14) | 0.0451 (14) | −0.0080 (11) | 0.0019 (12) | 0.0038 (11) |
C9 | 0.0469 (13) | 0.0682 (14) | 0.0418 (14) | −0.0061 (11) | 0.0018 (12) | −0.0013 (11) |
C10 | 0.0524 (14) | 0.0823 (18) | 0.0612 (17) | −0.0056 (14) | 0.0119 (15) | 0.0050 (14) |
C11 | 0.0662 (17) | 0.0833 (19) | 0.077 (2) | 0.0129 (15) | 0.0121 (18) | −0.0042 (16) |
C12 | 0.0748 (18) | 0.0687 (16) | 0.068 (2) | −0.0018 (14) | −0.0025 (17) | 0.0036 (15) |
C13 | 0.0686 (17) | 0.080 (2) | 0.062 (2) | −0.0203 (15) | 0.0052 (17) | 0.0047 (15) |
C14 | 0.0471 (13) | 0.0774 (18) | 0.0581 (18) | −0.0093 (13) | 0.0092 (14) | −0.0027 (14) |
S1—O4 | 1.4310 (19) | C5—C6 | 1.510 (4) |
S1—O5 | 1.4334 (18) | C6—H6A | 0.9600 |
S1—C9 | 1.755 (3) | C6—H6B | 0.9600 |
S1—C8 | 1.784 (2) | C6—H6C | 0.9600 |
O1—C1 | 1.415 (3) | C7—H7A | 0.9600 |
O1—C5 | 1.433 (3) | C7—H7B | 0.9600 |
O2—C5 | 1.409 (3) | C7—H7C | 0.9600 |
O2—C4 | 1.409 (4) | C8—H8A | 0.9700 |
O3—N1 | 1.290 (3) | C8—H8B | 0.9700 |
N1—C2 | 1.299 (3) | C9—C14 | 1.383 (3) |
N1—C3 | 1.485 (4) | C9—C10 | 1.387 (3) |
C1—C2 | 1.490 (4) | C10—C11 | 1.374 (4) |
C1—C4 | 1.530 (4) | C10—H10 | 0.9300 |
C1—H1 | 0.9800 | C11—C12 | 1.371 (4) |
C2—C8 | 1.471 (3) | C11—H11 | 0.9300 |
C3—C4 | 1.506 (5) | C12—C13 | 1.382 (4) |
C3—H3A | 0.9700 | C12—H12 | 0.9300 |
C3—H3B | 0.9700 | C13—C14 | 1.373 (4) |
C4—H4 | 0.9800 | C13—H13 | 0.9300 |
C5—C7 | 1.492 (4) | C14—H14 | 0.9300 |
O4—S1—O5 | 119.46 (14) | C7—C5—C6 | 112.5 (3) |
O4—S1—C9 | 109.47 (13) | C5—C6—H6A | 109.5 |
O5—S1—C9 | 108.16 (12) | C5—C6—H6B | 109.5 |
O4—S1—C8 | 107.06 (11) | H6A—C6—H6B | 109.5 |
O5—S1—C8 | 107.58 (13) | C5—C6—H6C | 109.5 |
C9—S1—C8 | 104.02 (12) | H6A—C6—H6C | 109.5 |
C1—O1—C5 | 108.01 (19) | H6B—C6—H6C | 109.5 |
C5—O2—C4 | 112.0 (2) | C5—C7—H7A | 109.5 |
O3—N1—C2 | 127.8 (2) | C5—C7—H7B | 109.5 |
O3—N1—C3 | 119.7 (2) | H7A—C7—H7B | 109.5 |
C2—N1—C3 | 112.5 (2) | C5—C7—H7C | 109.5 |
O1—C1—C2 | 113.9 (2) | H7A—C7—H7C | 109.5 |
O1—C1—C4 | 104.8 (2) | H7B—C7—H7C | 109.5 |
C2—C1—C4 | 102.9 (2) | C2—C8—S1 | 113.50 (17) |
O1—C1—H1 | 111.6 | C2—C8—H8A | 108.9 |
C2—C1—H1 | 111.6 | S1—C8—H8A | 108.9 |
C4—C1—H1 | 111.6 | C2—C8—H8B | 108.9 |
N1—C2—C8 | 121.4 (2) | S1—C8—H8B | 108.9 |
N1—C2—C1 | 111.7 (2) | H8A—C8—H8B | 107.7 |
C8—C2—C1 | 126.8 (2) | C14—C9—C10 | 120.8 (3) |
N1—C3—C4 | 103.1 (2) | C14—C9—S1 | 120.1 (2) |
N1—C3—H3A | 111.1 | C10—C9—S1 | 119.10 (19) |
C4—C3—H3A | 111.1 | C11—C10—C9 | 118.4 (3) |
N1—C3—H3B | 111.1 | C11—C10—H10 | 120.8 |
C4—C3—H3B | 111.1 | C9—C10—H10 | 120.8 |
H3A—C3—H3B | 109.1 | C12—C11—C10 | 121.6 (3) |
O2—C4—C3 | 110.3 (3) | C12—C11—H11 | 119.2 |
O2—C4—C1 | 102.9 (2) | C10—C11—H11 | 119.2 |
C3—C4—C1 | 105.6 (2) | C11—C12—C13 | 119.3 (3) |
O2—C4—H4 | 112.5 | C11—C12—H12 | 120.4 |
C3—C4—H4 | 112.5 | C13—C12—H12 | 120.4 |
C1—C4—H4 | 112.5 | C14—C13—C12 | 120.5 (3) |
O2—C5—O1 | 106.07 (19) | C14—C13—H13 | 119.8 |
O2—C5—C7 | 110.4 (3) | C12—C13—H13 | 119.8 |
O1—C5—C7 | 109.1 (2) | C13—C14—C9 | 119.4 (3) |
O2—C5—C6 | 109.1 (2) | C13—C14—H14 | 120.3 |
O1—C5—C6 | 109.4 (2) | C9—C14—H14 | 120.3 |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O4i | 0.98 | 2.50 | 3.389 (2) | 151 |
C12—H12···O3ii | 0.93 | 2.51 | 3.270 (4) | 139 |
Symmetry codes: (i) −x+3/2, −y, z+1/2; (ii) x−1/2, −y−1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C14H17NO5S |
Mr | 311.35 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 5.6424 (2), 15.5592 (7), 16.9097 (8) |
V (Å3) | 1484.52 (11) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 2.14 |
Crystal size (mm) | 0.10 × 0.08 × 0.06 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2006) |
Tmin, Tmax | 0.815, 0.880 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8018, 2487, 2159 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.599 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.084, 1.06 |
No. of reflections | 2487 |
No. of parameters | 192 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.14, −0.15 |
Absolute structure | Flack (1983), 907 Friedel pairs |
Absolute structure parameter | 0.06 (2) |
Computer programs: APEX2 (Bruker 2006), SAINT (Bruker 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O4i | 0.98 | 2.50 | 3.389 (2) | 151 |
C12—H12···O3ii | 0.93 | 2.51 | 3.270 (4) | 139 |
Symmetry codes: (i) −x+3/2, −y, z+1/2; (ii) x−1/2, −y−1/2, −z+1. |
Acknowledgements
The authors are grateful to the MICINN (CTQ2009–1172), Junta de Castilla y Leon for financial support (GR178 and SA001A09) and for the doctoral fellowships awarded to MFF.
References
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Recently there has been an enormous interest in organocatalysis (Berkessel & Groger et al. 2005 and Macmillan, 2008). Among the many known organocatalysts L-proline is perhaps the one which has been most studied. This fact has led to the appearance of many analogues (Andrey et al., 2004; Wang et al., 2005; Cobb et al., 2004; Tanaka et al., 2004). In our research group we have developed new organocatalyst using nitrones as starting material (Flores et al., 2010). This catalyst was obtained from chiral hydroxylamine (I) (Fig. 1). Here we communicate the oxidation of this compound into nitrone II and the crystal structure determination.
The crystal contains an unique molecule in the asymmetric unit (Fig. 2). The title molecule consists of a pyrroline-N-oxide ring with a phenylsulfonylmethylgroup and an isopropylidenedioxy group as susbtituents. All the bond lengths and angles are within the normal ranges. Statistically no diference is observed between the S1—O4 = 1.4310 (19) Å and S1—O5 = 1.4334 (18) Å distances suggesting that the two oxygen are very similar. The S1—C8 and S1—C9 bond lengths are 1.784 (2) Å and 1.755 (3) Å, respectively. The C—S—C and O—S—O angles are 104.02 (12)° and 119.46 (14)°, respectively. The large O—S—O angle and this deviation from the optimal 109.5° angle can be explained by the repulsion of the lone pairs of the oxygen placing the oxygen atoms as far away from each other as possible and thus minimizing the C—S—C angle. The molecule is twisted at the C—S bond being the C2—C8—S1—C9 torsion angle of -59.4 (7)°. The carbonyl group at atom N1 is desviated from the planar conformation with the pyrroline ring being the O3—N1—C3—C4 torsion angle of 165.9 (5)°.
Crystal packing (Fig. 3) is stabilized by two intermolecular C-H···O interactions. One occurs between the carbon atom (C4) of the isopropylidenedioxypyrroline group and the oxygen atom (O4) of the phenylsufonylmethyl group of the neighboring molecule oriented in the opposite direction along c axis with d(C4-H4···O4) = 3.389 (2) Å and <C4-H4···O4> = 151°. This leads to infinite molecular chains running along the [001] direction, which are joined each other along the b axis by another intermolecular interaction between the oxygen atom (O3) of the pyrroline group and the carbon atom (C12) of the phenyl group of the next molecule with d(C12-H3···O3) = 3.270 (1) Å and <C12-H3···O3> = 139°.