SYNTHESIS OF NEW IMIDAZO[4,5-D][1,3]DIAZEPINE DERIVATIVES FROM 5-AMINO-4-(CYANOFORMIMIDOYL)IMIDAZOLES

N-1-[(Z)-2-Amino-1,2-dicyanovinyl]formamidines 1a-d react readily with tosyl isocyanate to form novel ed-5-oxo-7-tosylaminoimidazo[4,5-d][1, 3]diazepines 6a-d rather than the 6-cyano-2-oxopurine derivatives 5a-d expected. Compound 5a has been synthesized from 1a by reaction with e thyl chloroformate and base-catalyzed cyclization of the resultant eth oxycarbonylamino-4-(cyanoformimidoyl)imidazole. Treatment of the 5-ami no-4-cyanoimidazoles 7a and b with tosyl isocyanate under similar cond itions gives the 4-cyano-5-(3'-tosylureido)imidazoles 8a and b, which on treatment with ethanolic ammonia cyclizes to the corresponding isog uanines 10a and b.