ChemInform Abstract: Oxidation of Biginelli Reaction Products: Synthesis of 2‐Unsubstituted 1,4‐Dihydropyrimidines, Pyrimidines, and 2‐Hydroxypyrimidines.

Abstract

I) with hydrogen peroxide or Oxone gives dihydropyrimidines which are easily further oxidized to pyrimidines (III) with KMnO4. Direct treatment of (I) and the oxo analogues (V) with KMnO4 yields 2-hydroxypyrimidines. -(KIM, S. S.; CHOI, B. S.; LEE, J. H.; LEE, K. K.; LEE, T. H.; KIM, Y. H.; SHIN*, H.; Synlett 2009, 4, 599-602; Chem. Dev. Div., LG Life Sci., Ltd./R&D, Daejeon 305-380, S. Korea; Eng.) -Mais 28-143

Synthesis of 3,4-Dihydropyrimidin(thio)one Containing Scaffold: Biginelli-like Reactions

“…N1, N3-diacyl-3,4-dihydropyrimidinones as acyl group transfer reagents. Shin et al described the synthesis of 2-unsubstituted pyrimidine rings from Biginelli products, not easily accessible[189]. The oxidation of dihydropirimin-2(1H)-thiones with oxone on wet alumina or hydrogen peroxide in the presence of a catalytic amount of vanadyl sulfate provided dihydropyrimidines 258 that were further oxidized to 2-unsubstituted pyrimidines 259 in good yields with KMnO 4 .…”