A convenient route to diazepines by intramolecular cyclisation of carbonylazides

The appropriate substituted carbonylazides I treated with warm acetic acid give the corresponding acetamide IV or the cyclic lactam VI . This is a convenient route to 10,11-Dihydro-5H-pyrrolo1,2-a]1,4]-benzodiazepin-11-one and 10,11-Dihydro-4H-thieno2,3-e]pyrrolo1,2-a]1,4]diazepin-10-one.