1-Methyl-3-(2-methyl­phen­yl)-3a-nitro-1,2,3,3a,4,9b-hexa­hydro­chromeno[4,3-b]pyrrole

S Sundaramoorthy; N Sivakumar; M Bakthadoss; D Velmurugan

doi:10.1107/S1600536812020338

. 2012 May 16;68(Pt 6):o1735. doi: 10.1107/S1600536812020338

1-Methyl-3-(2-methylphenyl)-3a-nitro-1,2,3,3a,4,9b-hexahydrochromeno[4,3-b]pyrrole

S Sundaramoorthy ^a, N Sivakumar ^b, M Bakthadoss ^b, D Velmurugan ^a,^*

PMCID: PMC3379324 PMID: 22719522

Abstract

The asymmetric unit of the title compound, C₁₉H₂₀N₂O₃, contains two independent molecules in both of which the pyrrolidine ring adopts an envelope conformation, but with a C atom as the flap in one molecule and the N atom in the other. The pyran ring adopts a half-chair conformation in both molecules. In the crystal, molecules are linked via C—H⋯O hydrogen bonds and C—H⋯π interactions.

Related literature

For a related structure, see: Chitra Devi et al. (2011 ▶). For ring conformations, see: Cremer & Pople (1975 ▶). graphic file with name e-68-o1735-scheme1.jpg

Experimental

Crystal data

C₁₉H₂₀N₂O₃
M _r = 324.37
Monoclinic,
a = 17.8782 (13) Å
b = 8.0447 (6) Å
c = 23.4660 (17) Å
β = 97.605 (2)°
V = 3345.3 (4) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.24 × 0.23 × 0.2 mm

Data collection

Bruker SMART APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.979, T _max = 0.983
30608 measured reflections
8190 independent reflections
5303 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.149
S = 1.00
8190 reflections
437 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812020338/bt5906sup1.cif

e-68-o1735-sup1.cif^{(31.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812020338/bt5906Isup2.hkl

e-68-o1735-Isup2.hkl^{(392.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812020338/bt5906Isup3.cml

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

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

Cg11 and Cg3 are the centroids of the C12′–C17′ and C1–C6 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯O1′ⁱ	0.93	2.60	3.282 (3)	131
C4′—H4′⋯O2ⁱⁱ	0.93	2.56	3.407 (3)	152
C14′—H14′⋯O2	0.93	2.59	3.327 (2)	136
C19′—H19F⋯O1′	0.96	2.54	3.391 (3)	148
C18—H18A⋯Cg11ⁱ	0.96	2.92	3.854 (2)	166
C19′—H19E⋯Cg3ⁱⁱⁱ	0.96	2.94	3.811 (3)	152

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

The authors thank the TBI X-ray Facility, CAS in Crystallography and Biophysics, University of Madras, India, for the data collection and SS and DV thank the University Grants Commission (UGC & SAP) for financial support.

supplementary crystallographic information

Comment

In order to obtain detailed information on its molecular conformation, the X-ray structure of the title compound has been determined and is discussed here.

The geometric parameters of the title molecule (Fig. 1) agree well with reported similar structure (Chitra Devi et al., 2011). The pyrrolidine rings make the dihedral angle of 54.29 (9)° and 40.05 (9)° with benzene rings of chromeno moiety for both the molecules. In both the molecules, the average dihedral angle between methyl benzene ring and pyrrolidine ring is 66.83 (9)°. The sum of bond angles around N1 [331.9 (3)°, 329.15 (4)°] and around N2 atom [359.9 (5)°, 360.2 (5)°] indicate sp³ and sp² hybridizations in two molecules, respectively.

The pyran ring adopts half-chair conformation, with the puckering parameters (Cremer & Pople, 1975) of q₂ = 0.3472 (16) Å, q₃ = 0.2945 (15) Å, φ = 97.6 (2)°, in one molecule and in the other molecule q₂ = 0.3655 (17) Å, q₃ = 0.2930 (17) Å, φ = 77.4 (2)°. The crystal packing is stabilized by C—H···O and C—H···π interactions. Atom C15 donating one proton to O1' at (x, y - 1, z) and the C4' atom in the other molecule donating one proton to O2 at (-x + 1, -y + 1, -z) form C—H···O hydrogen bonds.

Experimental

A mixture of (2E)-methyl-2-(2-formylphenoxy)methyl-3-phenylacrylate (2 mmol, 0.592 g) and sarcosine (2 mmol, 0.178 g) in acetonitrile (8 ml) was refluxed for 5 h. After the completion of the reaction as indicated by TLC, the reaction mixture was concentrated and the resulting crude mass was diluted with water (15 ml) and extracted with ethyl acetate (3 X 15 ml). The combined organic layer obtained was washed with brine (2 X 10 ml) and dried over anhydrous Na2SO4. The organic layer was concentrated and purified by column chromatography on silica gel (Acme 100–200 mesh), ethyl acetate: hexane (1: 9) to afford the pure methyl 1,2,3,3a,4,9 b-hexahydro-1-methyl-3-phenyl chromeno[4,3-b] pyrro-le-3a-carboxytate as colourless solid in 91% (0.588 g) yieid.