Efficient access to 2,7-diarylated pyrido[3,2- d]pyrimidines involving regioselective pallado-dehalogenation and suzuki cross-coupling reactions

摘要

An efficient and original synthesis of various 2,7-disubstituted pyrido[3,2-d]pyrimidines is reported. The first synthesis of 2,7-dichloropyrido[3,2-d]pyrimidine, by selective palladium-catalyzed dechlorination of 2,4,7-trichloropyrido[3,2-d]pyrimidine at C-4, is described and its chemical reactivity is examined. Diarylated pyrido[3,2-d]pyrimidines were synthesized starting from 2,7-dichloropyrido[3,2-d]pyrimidine by regioselective Suzuki cross-coupling reaction at C-2 and then at C-7. ? Georg Thieme Verlag Stuttgart ?? New York.