Synthesis and Azido-Tetrazole Tautomerism of New Methylsulfanyl Thieno[3,2-d]pyrimidine Derivatives

Abstract

New 7-amino, 7-azido, and 7-alkylsulfanyl derivatives have been synthesized from 7-chloro-9-(methylsulfanyl)-4-(propan-2-yl)-2,3-dihydro-1H-cyclopenta[4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine. 7-Azido-9-(methylsulfanyl)-4-(propan-2-yl)-2,3-dihydro-1H-cyclopenta[4′,5′]pyrido[3′,2′:4,5]thieno[3,2-d]-pyrimidine has been found to exist in solution as a mixture of azido and tetrazole tautomers, whereas only its tetrazole form is present in the crystalline state.