2-[(Z)-4,7-Dichloro-3,3-dimethyl-2,3-dihydro-1H-indol-2-yl­idene]-3-oxopropane­nitrile

In the title compound, C₁₃H₁₀Cl₂N₂O, the ring N atom and its three attached atoms are essentially coplanar with angles adding to 359.8°, indicating conjugation with the 2-formyl­acrylonitrile subunit. The aldehyde group is oriented to place the carbonyl O atom 2.02 (3) Å from the N—H hydrogen atom. Intra­molecular N—H...O and C—H...Cl inter­actions occur. The geometry of the exocyclic double bond is Z. In the crystal, weak C—H...N hydrogen bonds link the mol­ecules into chains along [10].

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.