(E)-Methyl 2,6-dichloro-N-cyanobenzimidate

The molecule of the title compound, C9H6Cl2N2O, displays an E conformation about the C=N double bond. The N-cyanoimidate fragment is substantially planar [maximum deviation 0.010 (4) Å] and perpendicular to the benzene ring [dihedral angle = 88.50 (14)°]. In the crystal packing, intermolecular Cl⋯Cl interactions [3.490 (2) Å] are observed.

The molecule of the title compound, C 9 H 6 Cl 2 N 2 O, displays an E conformation about the C N double bond. The Ncyanoimidate fragment is substantially planar [maximum deviation 0.010 (4) Å ] and perpendicular to the benzene ring [dihedral angle = 88.50 (14) ]. In the crystal packing, intermolecular ClÁ Á ÁCl interactions [3.490 (2) Å ] are observed.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RZ2343).

Comment
In the course of our studies aimed to prepare substituted cyanoimidates (Huffman & Schaefer, 1963) from the corresponding aromatic aldehyde by oxidation using 1-bromopyrrolidine-2,5-dione, the title compound was obtained in 84% yield, and its crystal structure is reported herein.

Experimental
A mixture of 2,6-dichlorobenzaldehyde (1 mmol), H 2 NCN (3 equiv) and t-BuONa (3 equiv) in MeOH (8 ml) was stirred for 30 min at room temperature, then N-bromosuccinimide (NBS; 3 equiv) was added. After stirring for 12 h at 323 K, the mixture was purified by flash chromatography on silica gel with petroleum ether/ethyl acetate (100:1-25:1 v/v) as eluent to give the title compound in 84% yield. Colourless crystals suitable for X-ray analysis were obtained by slow evaporation of a petroleum ether/acetyl acetate solution (25:1 v/v) at room temperature.

Refinement
H atoms were positioned geometrically (C-H = 0.93-0.96 Å) and refined using a riding model, with U iso (H) = 1.2U eq (C) or 1.5U eq (C) for methyl H atoms. Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 50% probability level. 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 Rfactors(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.