Abstract Treatment of 6-amino-1, 3-dimethyl-5-nitrosouracil (Ia) with dimethyl acetylenedicarboxylate (DMAD) in dimethylformamide (DMF) afforded 6, 7-bis (dimethoxycarbonyl)-1, 3-dimethyllumazine (II). Similarly, the reaction of 6-amino-1, 3- dimethyl-5-phenylazouracil with DMAD gave also II. Hydrolysis of II with hydrochloric acid gave 1, 3-dimethyllumazine-6-carboxylic acid (III). III was chlorinated with thionyl chloride ...
