Intramolecular amidation:synthesis of novel imidazo[2,1-b][1,3,4|thiadiazole and imidazo[2,1-b)[1,3]thiazole fused diazepinones

摘要

Novel heterocyclic systems 2-alkyl/aryl-9-(2-hydroxybenzylidene)-7,9-dihydro-8H-[1,3,4]thiadiazolo[2',3':2,3]imidazo-[4,5-d][1,2]diazepin-8-one and 9-(2-hydroxy-benzylidene)-3,3-dimethyl-3,4,7,9-tetrahydro-2H-11-thia-4b,6,7,10-tetraazaindeno-[1,2-a]azulene-1,8-dione are synthesized via an intramolecular amidation reaction.An interesting ring opening and cyclization of 2-alkyl/aryl-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1 ,3,4]thiadiazole-5-carbaldehyde and 6,6-dimethyl-8-oxo-2-(2-oxo-2H-chromen-3-yl)-5,6,7,8-tetrahydroimidazo[2,1-6][1,3]benzothiazole-3-carbaldehyde are discussed.