Аннотация:
6-Amino-1,3-dimethyluracil reacts with two molecules of alkanals (butanal or pentanal) in formic acid to give 1,3,7,9-tetramethyl- 2,4,6,8-tetraoxopyrido[2,3-d][6,5-d’]dipyrimidine and the corresponding 3,4-dialkyl-substituted 6,8-dimethyl-5,7-dioxopyrido[2,3-d]- pyrimidines.