Synthesis of C2-functionalized pyrimidines from 3,4-dihydropyrimidin-2(1H)-ones by the Mitsunobu coupling reaction

The Biginelli 3,4-dihydropyrimidin-2(1H)-one was converted to various C2-multifunctionalized pyrimidines via the dehydrogenation and Mitsunobu reaction using amines, alcohols, phenols and carboxylic acids as nucleophiles. A possible mechanism was also proposed to rationalize the formation of products.