Ethyl N-(3-cyano-1H-indol-2-yl)formimidate

In the title compound, C12H11N3O, the C=N imino bond is in an E conformation. In the crystal, adjacent molecules are linked by N–H⋯Ncyano hydrogen bonds, forming a chain running along [110].

In the title compound, C 12 H 11 N 3 O, the C N imino bond is in an E conformation. In the crystal, adjacent molecules are linked by N-HÁ Á ÁN cyano hydrogen bonds, forming a chain running along [110].

Related literature
The starting reactant was synthesized according to a literature method (Yang et al., 2010). Introduction of different groups into indole molecules can generate a series of bioactive derivatives, which have been the subject of much attention as anticancer drugs (Laird et al., 2000;Li et al., 2005).  Table 1 Hydrogen-bond geometry (Å , ).

Comment
The indole compounds play an important role in the pharmaceutical and agrochemical industries. Introduction of different groups into indole molecules can generate a series of bioactive derivatives, which have been the subject of much attention in anti-cancer drugs (Laird et al., 2000;Li et al., 2005). In our study, we report an indole compound.

Experimental
The starting reactant 1 was synthesized according to a literature method (Yang et al., 2010). (2) 2-amino-1H-indole-3-carbonitrile (6.29 g, 40 mmol) was suspended in dry acetonitrile (150 ml). Triethylorthoformate (10.92 ml, 9.73 g, 60 mmol) was added and the mixture was heated at reflux temperature for 1 hour. The dark brown solution was cooled to room temperature and filtered through filter paper. The acetonitrile was removed on a rotoevaporator to afford 2 as a brown solid. 1

Refinement
H atoms bond to N were located in a difference map and refined with distance of N-H = 0.866 Å (18) and U iso (H) = 1.2U eq (N). other H atoms attached to C were fixed geometrically and treated as riding with C-H = 0.96 Å (methyl) or 0.93 Å (aromatic) and with U iso (H) = 1.2U eq (aromatic) or U iso (H) = 1.5U eq (methyl).

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. 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 > 2sigma(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.