Synthesis and characterization of new pyrido- and pyrazolopyrimidine derivatives using 2-substituted vinamidinium salts

Abstract

Several novel pyrido- and pyrazolopyrimidine derivatives were readily synthesized by reaction of 6-aminouracil or 3(5)-aminopyrazole with 2-substituted vinamidinium salts. The reactions were carried out in a relatively short time without any base or catalyst. The structures of the synthesized compounds were confirmed by UV-vis, IR, and 1H and 13C NMR spectroscopy, as well as mass spectrometry and elemental analysis. The obtained results showed that tautomers of 3(5)-amino-1(H)-pyrazole can participate in the formation of the new pyrido- and pyrazolopyrimidine derivatives with their respective most nucleophilic centers N-2 and C-4.