THE FIRST EXAMPLES OF ISOLATED N-UNSUBSTITUTED 1H-1, 4-BENZODIAZEPINES

Abstract

The photolysis in the presence of sodium methoxide of the 4-azidoquinolines (5a-g) having a carbonyl group or its analogue in the 2- or 8-position resulted in ring expansion to give the stable N-unsubstituted 1H-1, 4-benzodiazepines (6a-g). These were assumed to be stabilized by intramolecular hydrogen bonding between the NH and the 2- or 9-acyl groups. It is known that the N-unsubstituted 1H-1, 4-benzodiazepines having no acyl group are too unstable to be isolated.