Reaction of N,N-dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) with 1,3-dimethyl-4-aminouracils. A new “one pot” synthesis of 3-aryl-(and 3-alkyl)-4,6-dimethyl-5,7-dioxo-1,2,3-triazolo[4,5-d]pyrimidines (8-azatheophyllines) via a diazo group transfer process

N,N-Dimethylazidochloromethyleniminium chloride (azidophosgeniminium chloride) ( 1 ) reacts by diazo group transfer with 1,3-dimethyl-4-aryl-(and alkyl)aminouracils 4 to give, under mild “one pot” reaction conditions, a very good yield of 3-aryl-(and 3-alkyl)-4,6-dimethyl-5,7-dioxo-1,2,3-triazolo4,5-d]pyrimidines (8-azatheophyllines) 8 . That reaction proceeds, very likely, through formation of non-isolated 4-imino-5-diazouracils 6 .