Synthesis and Properties of 7-Alkoxyfurazanopyrimidines and Their Use in the Preparation of 4-Alkoxypteridines and N3-Substituted Pterins

Article abstract of DOI:10.1021/jo00225a030

Reaction of 5-amino-7-(methylthio)furazano<3,4-d>pyrimidine (4) with a range of alcohols in the presence of bromine leads to the formation of the corresponding 5-amino-7-alkoxyfurazano<3,4-d>pyrimidines (5-10).These on hydrogenolysis afford 6-alkoxy-2,4,5-triaminopyrimidines, which can be condensed with benzil to give 2-amino-4-alkoxypteridines (17-21).The product from hydrogenolysis of 5-amino-7-(2-chloroethoxy)furazano<3,4-d>pyrimidine (7), however, undergoes intramolecular cyclization to a 2,3-dihydrooxazolo<3,2-c>pyrimidinium compound (23), which behaves as a heteronuclear resonance stabilized ambident cation.Reaction of it with nucleophiles followed by condensation with benzil leads to N³-substituted pteridines.