N-Piperonyl analogue of the atypical antipsychotic clozapine

The crystal structure of 11-[4-(1,3-benzodioxol-5-ylmethyl)-piperazino]-8-chloro-5H-dibenzo[b,e]1,4] diazepine, C₂₅H₂₃-ClN₄O₂, confirms the buckled nature of the dibenzodiazepine nucleus, with the central seven-membered heterocycle in a boat conformation and the dihedral angle between the planes of the aromatic rings being similar to that found for the parent compound, clozapine. The piperazine ring displays an almost perfect chair conformation, with the piperonyl group assuming an equatorial orientation. The relative position of the dibenzodiazepine and piperazine ring systems is controlled by the planarity of the piperazine N atom in the amidine moiety.