[4+3]-Annulation of 3-Cyano-4-aryl-2-iminochromenes with 1,2-Diaminobenzene: An Access to Novel Chromenobenzodiazepines

Abstract

Abstract 3-Cyano-4-aryl-2-iminochromenes undergo [4+3]-annulation with 1,2-diaminobenzene under mild acidic conditions to generate novel chromenobenzodiazepines in good yields. The annulation reaction was also successful with 2-aminophenol and 2-aminothiophenol. The chromenobenzodiazepines could be conveniently reduced to the corresponding 4H-chromenobenzodiazepines under mild acidic conditions.

Keywords

• 3-cyano-4-aryl-2-iminochromene
• 1,2-diaminobenzene
• [4+3]-annulation
• chromenobenzodiazepine
• chromenobenzoazepine