Studies of seven-membered heterocycles. XXXII. Synthesis of N-unsubstituted 1H-1,4-benzodiazepines stabilized by intramolecular hydrogen bonding.
作者:Haruki SASHIDA、Mamoru KANAME、Takashi TSUCHIYA
DOI:10.1248/cpb.38.2919
日期:——
The stable N-unsubstituted 1H-1, 4-benzodiazepines (12a-l) having a carbonyl group or its analogue at the 2- or 9-position were prepared from the 4-azidoquinolines (13a-l) by photoreaction in the presence of sodium methoxide.It is known that N-unsubstituetd 1H-1, 4-benzodiazepines having no carbonyl group are too unstable to be isolated.Based on the spectral data, the benzodiazepines (12) isolated are assumed to be stabilized by intramolecular hydrogen bonding between the 1-NH hydrogen and the 2- or 9-carbonyl oxygen, thus allowing their isolation.