Chlorotrimethylsilane-promoted synthesis of 1,2,4-triazolopyrimidines from 3,5-diamino-1,2,4-triazoles and pentane-2,4-diones

摘要

An efficient synthesis of 2-amino-1-R-[1,2,4]triazolo[1,5-a]-pyrimidinium or 3-amino-2-R[1,2,4]triazolo[4,3-a]pyrimidinium chloride derivatives by heterocyclization of 3,5-diamino-1-R-1,2,4-triazoles (R = Alk or Ar) with pentane-2,4-diones was developed. The process is promoted by chlorotrimethylsilane which plays the dual role of carbonyl-activating agent and water scavenger.