Pyrido[2,3-d]pyrimidines. 2. Reactions of 2,4,5-trioxo-7-amino-8H-pyrido[2,3-d]pyrimidines with electrophilic agents

1,3-Dimethyl-2,4,5-trioxo-7-amino-8H-pyrido[2,3-d]pyrimidine has been brominated, chlorosulfonated, treated with potassium nitrite in acidic medium, and with the Vilsmeier reagent. Acylation and alkylation of 1,3-dimethyl-2,4,5-trioxo-6-bromo-7-aminopyrido[2,3-d]pyrimidine is also discussed.For Communication 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 662–666, May, 1990.