Recent advances for the synthesis of dihydropyrimidines through Biginelli-like reactions based on in situ prepared aldehydes

Dihydropyrimidinones have a variety of pharmacological and ­therapeutic uses. The Biginelli reaction is the cyclocondensation of aldehydes, urea, and acetoacetic ester that produces 3,4-dihydropyrimidine-2-ones. Because of the substantial biological and pharmacological benefits of dihydropyrimidinones, the Biginelli reaction has consistently received attention. The dihydropyrimidines were synthesized via modification of classical Biginelli substrates using aldehyde alternatives. The alcohols, halogenated and methyl arenes, are inexpensive and abundant in nature. Therefore, the alcohols, halogenated and methyl arenes, were used as surrogates of aldehydes in the environmentally friendly production of dihydropyrimidines. So, the topic of this review is the synthesizing of dihydropyrimidines using a Biginelli-like reaction based on in situ-prepared aldehydes and urea/thiourea.