(3aR,8bR)-3a,8b-Dihydroxy-2-methylsulfanyl-3-nitro-1-phenyl-1,8b-dihydroindeno[1,2-b]pyrrol-4(3aH)-one

In the title compound, C18H14N2O5, the pyrrolidine ring adopts a shallow envelope conformation, with the C atom bearing the OH group (and remote from the N atom) displaced by 0.257 (2) Å from the other atoms. The cyclopentane ring has a twisted conformation about the C—C bond bearing one =O and one —OH grouping. The dihedral angle between the five-membered rings (all atoms) is 65.54 (9)° and the OH groups lie to the same side of the ring-junction. The molecular structure features a weak intramolecular O—H⋯O bond and a possible C—H⋯π interaction. In the crystal, the molecules are linked into [010] chains by O—H⋯O hydrogen bonds. Weak C—H⋯O bonds connect the chains into (100) sheets.

In the title compound, C 18 H 14 N 2 O 5 , the pyrrolidine ring adopts a shallow envelope conformation, with the C atom bearing the OH group (and remote from the N atom) displaced by 0.257 (2) Å from the other atoms. The cyclopentane ring has a twisted conformation about the C-C bond bearing one =O and one -OH grouping. The dihedral angle between the five-membered rings (all atoms) is 65.54 (9) and the OH groups lie to the same side of the ring-junction. The molecular structure features a weak intramolecular O-HÁ Á ÁO bond and a possible C-HÁ Á Á interaction. In the crystal, the molecules are linked into [010] chains by O-HÁ Á ÁO hydrogen bonds. Weak C-HÁ Á ÁO bonds connect the chains into (100) sheets.
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; 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. Pyrrolidine-containing compounds are of significant importance because of their biological activities and widespread employment in catalysis (Grigg, 1995;Kravchenko et al., 2005). As part of our own studies in this area, we have undertaken the crystal structure determination of the title compound, a pyrrolidine derivative,and the results are presented here.
The aryl ring makes the dihedral angle of 57.40 (1) ° with the mean plane of the pyrrolidine ring. The sum of the C-N-C angles around N1 (359.89 (1)°) atom is implying a noticeable flattening of the trigonal pyramidal geometry about N1.
The structure features a weak intra-molecular O-H···O interaction. An inter-molecular O2-H2···O5 inteaction forms a zig-zag chain along b axis and they are further connected by C11-H11···O4 inter-molecular interaction, forming a zigzag chain along c axis. A weak C-H···Cg1 interaction is also observed, as in Table 1 (Cg1 is the centroid of the benzene ring C13-C18).

Experimental
A mixture of (E)-N-(1-(methylthio)-2-nitrovinyl)aniline (1 mmol) with ninhydrin (1 mmol) in presence of glacial AcOH (3-5 drops) was thoroughly ground in a pestle and mortar at room temperature for 2-10 mins. Thereaction progress was monitored by thin layer chromatography. After completion of the reaction, the reaction mixture was triturated with crushed ice, the resulting solid filtered off and washed with water to afford the pure product. The compound was further recrystallized from ethanol to obtain colourless blocks. Melting point : 451K -453K. Yield : 94%.

Refinement
H atoms were placed at calculated positions and allowed to ride on their carrier atoms with C-H = 0.93-0.98Å. U iso = 1.2U eq (C) for CH 2 and CH groups and U iso = 1.5U eq (C) for CH 3 group.

Figure 1
The molecular structure of (I), showing 20% probability displacement ellipsoids. H-atoms are omitted for clarity.   where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.23 e Å −3 Δρ min = −0.19 e Å −3 Absolute structure: Flack (1983), 000 Friedel pairs Absolute structure parameter: 0.00 (6) Special details 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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ (F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F. 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger. Hydrogen-bond geometry (Å, º) Cg1 is the centroid of the C13-C18 benzene ring. Symmetry codes: (i) x+1/2, −y−1/2, −z; (ii) −x−1/2, −y, z+1/2.