Dihydro-1,3-diazepinones and diazabicyclo[3.2.0]heptenones from pyridyl azides

Abstract

2-Alkoxy-1H-1,3-diazepines 5 and 7, 2-dialkylamino-5H-1,3-diazepines 6, 2,3-dihydro-1H-1,3-diazepin-2-ones 8 and 2,4-diazabicyclo[3.2.0]hepten-3-ones 9 are obtained by photolysis of tetrazolo[1,5-a]pyridines or 2-azidopyridines 1/2, including the unsubstituted parent compounds; the relative stabilities of the 2-alkoxy- and 2-dialkylamino-1,3-diazepines 5 and 6 are in excellent agreement with ab initio energy calculations.