Abstract Cyano-substituted tetrazolo [1, 5-a] pyridines/2-azidopyridines 8T and 15T undergo thermal ring opening to the azides 8A and 15A. Solution photolysis causes nitrogen elimination and ring expansion to 1, 3-diazacyclohepta-1, 2, 4, 6-tetraenes 10 and 17, which react with alcohols to afford 2-alkoxy-1H-1, 3-diazepines, with secondary amines to 2- dialkylamino-5H-1, 3-diazepines, and with water to 1, 3-diazepin-2-ones (12–14, 19, 21). ...
