2-(4-Chloro-3,3,7-trimethyl-2,3-dihydro-1H-indol-2-ylidene)-2-cyanoacetamide

Reaction of 2-(4-chloro-3,3,7-trimethyl-2,3-dihydro-1H-indol-2-ylidene)propanedial with hydroxylamine gives the title compound, C14H14ClN3O, in which the ring N atom is essentially planar [sum of angles around the ring N atom = 361°], indicating conjugation with the 2-cyanoacrylamide unit. The orientation of the acetamide group arises from intramolecular hydrogen bonding between the indole N—H and carbonyl groups. In the crystal, inversion-related acetamide groups form N—H...O hydrogen-bonded dimers in graph-set R22(8) motifs, whilst dimers are also formed by pairs of amine–nitrile N—H...N hydrogen bonds in R22(12) motifs. These interactions together generate ribbons that propagate along the b-axis direction.