Chapter 2 - Synthetic strategies of dihydropyrimidinones

Abstract

Owing to their role in a number of therapeutic actions, dihydropyrimidinones (DHPMs) are regarded as important heterocyclic scaffolds. The chemistry of Biginelli motifs, notably the DHPMs, has been studied in the drug development process as a result of the widespread use of various Biginelli products in several disciplines. The synthetic reactions to obtain DHPMs can broadly be classified into two categories: the classical methods and the nonclassical methods. Various strategies in the classical method of synthesis include variations in the reagents and variations in catalysts, as well as variations in the reaction conditions. The synthesis of DHPMs is an example of a multicomponent reaction (MCR), which includes the reaction of an aromatic aldehyde, a β-ketoester, and urea/thiourea. Several nonclassical methods have also been successful in synthesizing DHPMs in moderate-to-good yields which include methods such as the utilization of microwave, ultrasonication, and solvent-free. In this chapter, numerous synthetic processes that are employed to synthesize DHPMs are investigated. An in-depth review of recent literature concerning the synthesis of DHPMs by different classical and nonclassical methods was carried out, and the important aspects are summarized in this chapter.