3-(2,3-Dioxoindolin-1-yl)propanenitrile

The asymmetric unit of the title compound, C11H8N2O2, contains two independent molecules (A and B). Each molecule is build up from fused five- and six-membered rings with the former linked to a cyanoethyl group. The indoline ring and two carbonyl O atoms of each molecule are nearly coplanar, with the largest deviations from the mean planes being 0.0198 (9) (molecule A) and 0.0902 (9) Å (molecule B), each by a carbonyl O atom. The fused ring system is nearly perpendicular to the mean plane passing through the cyanoethyl chains, as indicated by the dihedral angles between them of 69.72 (9) (molecule A) and 69.15 (9)° (molecule B). In the crystal, molecules are linked by C—H⋯O and π–π [intercentroid distance between inversion-related indoline (A) rings = 3.6804 (7) Å] interactions into a double layer that stacks along the a-axis direction.

The asymmetric unit of the title compound, C 11 H 8 N 2 O 2 , contains two independent molecules (A and B). Each molecule is build up from fused five-and six-membered rings with the former linked to a cyanoethyl group. The indoline ring and two carbonyl O atoms of each molecule are nearly coplanar, with the largest deviations from the mean planes being 0.0198 (9) (molecule A) and 0.0902 (9) Å (molecule B), each by a carbonyl O atom. The fused ring system is nearly perpendicular to the mean plane passing through the cyanoethyl chains, as indicated by the dihedral angles between them of 69.72 (9) (molecule A) and 69.15 (9) (molecule B). In the crystal, molecules are linked by C-HÁ Á ÁO and -[intercentroid distance between inversion-related indoline (A) rings = 3.6804 (7) Å ] interactions into a double layer that stacks along the a-axis direction.

Structural commentary
Heterocyclic compounds are acquiring more importance in recent years because of their broad pharmacological activities.
Isatin and its derivatives are used in organic synthesis and in evaluating new product possessing different biological activities. Isatin derivatives have been reported to show considerable pharmacological actions such as, anti-convulsant, anti-anixity and anti-psychoactives activities (Bhrigu et al., 2010;Ramachandran, 2011;Smitha et al., 2008). As a continuation of our research work devoted to the development of isatin derivatives (Qachchachi et al., 2013;Qachchachi et al., 2014), we report the synthesis of new indoline-2,3-dione derivative by action of alkyl halides to explore other applications.
Each independent molecule of title compound is build up from a fused five-and six-membered rings linked, to a cyanoethyl chain and to two carbonyl oxygen atoms as shown in Fig. 1. The indoline ring and the two ketonic oxygen atoms are nearly coplanar, with the largest deviation from the mean plane being 0.0198 (9) Å for O1 atom, and 0.0902 (9) Å for the O4 atom, respectively, in the first and second molecule. The fused ring system planes, (N1, C1 to C8) and (N3, C12 to C19), are nearly perpendicular to the mean plane passing through the cyanoethyl chains (N2, C9-C11 and N4, C20-C22) as indicated by the dihedral angles between them of 69.47 (9) and 69.06 (9)°, respectviely. The two molecules in the asymmetric unit have a similar conformation, except the cyanoethyl group orientation as shown in Fig. 2.
In the crystal, the molecules are linked by C-H···O hydrogen bonds, Table 1, and π-π interactions between the fiveand six-membered rings of the N1-containing molecule [inter-centroid distance = 3.6804 (7) Å for symmetry operation: 1-x, 1-y, 2-z] to form double layers that stack along the a axis.
The mixture was stirred for 48 h; the reaction was monitored by thin layer chromatography. The mixture was filtered and the solvent removed under vacuum. The solid obtained was recrystallized from ethanol to afford the title compound as orange crystals (yield: 52%; M.pt: 383 K).

Refinement
All H atoms could be located in a difference Fourier map. However, they were placed in calculated positions with C-H = 0.95 Å (aromatic) and C-H = 0.99 Å (methylene), and refined as riding on their parent atoms with U iso (H) = 1.2 U eq .

Figure 1
Molecular plot the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
View showing the fitting of the two molecules in the asymmetric unit.   (Clark & Reid, 1995) T min = 0.827, T max = 0.917 5751 measured reflections 3546 independent reflections 3292 reflections with I > 2σ(I) 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 > 2σ(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.