Facile conversion of Biginelli 3,4-dihydropyrimidin-2(1H)-thiones to 2-(2-hydroxy-2-arylvinyl) dihydropyrimidines via Eschenmoser coupling

A one-pot, two-step synthesis protocol for the conversion of Biginelli 3,4-dihydropyrimidin-2(1H)-thiones to 2-(2-hydroxy-2-arylvinyl) dihydropyrimidine (DHPM) derivatives via Eschenmoser sulfide contraction coupling is described. Solution phase as well as solid-supported protocol was carried out for the decoration of the Biginelli DHMP scaffold at the C-2 position. The scope of the optimized protocol is demonstrated for different DHMP precursors.