Parallel synthesis of dihydropyrimidinones using Yb(III)-resin and polymer-supported scavengers under solvent-free conditions. A green chemistry approach to the Biginelli reaction

An efficient synthesis of an array of 3,4-dihydropyrimidin-2-(1H)-ones using solid-supported ytterbium(III) reagent from aldehydes, 1,3-dicarbonyl compounds and urea (Biginelli reaction) under solvent-free conditions is described. Purification of each member of the library was carried out using a cocktail of acid and basic polymer-supported scavengers