AN IMPROVED PROCESS FOR THE PREPARATION OF 4,5,6-SUBSTITUTED 3,4-DIHYDROPYRIMIDIN-2-ONES AND THEIR 2-THIOXO ANALOGUES

摘要

The present invention relates to an improved process for the preparation of 4,5,6-substituted 3,4-dihydropyrimidin-2-ones and their 2-thioxo analogues wherein substitution at 4,5 and 6 is selected from the group consisting of H, alkyl, aryl, cycloalkyl, alkyl or aryl carboxylate group, polyhydroxy alkyl and polyhydroxy aryl catalyzed by tin (IV) chloride pentahydrate and silver triflate.