Acidic ionic liquid catalyzed Biginelli reaction under solvent-free conditions

Ionic liquids (ILs) are emerging as effective promoters and solvents for green chemical reactions. One of the most important advantages of ILs is the behavior of solvophobic interactions that generate an internal pressure, which promotes the association of the chemical reactants and reagents and also shows an acceleration of MCRs in comparison to conventional solvents.1 Dihydropyrimidines are an important class of compounds exhibiting broad spectra of pharmacological activities such as antiinflammatory, anti-microbial, α-1a-adrenergic receptor antagonist, and antihypertensives.2 The development of dihydropyrimidine templates as pharmacologically active compounds contributed toward Biginelli cyclocondensation applications in drug industry.3 In this study and order to introduce an inexpensive and environmentally benign catalyst for this reaction, [DABCO](SO3H)2(HSO4)2 is used as a reusable catalyst in the synthesis of dihydropyrimidines through Biginelli reaction (Fig. 1).

Keywords:

Dihydropyrimidines , Multicomponent reaction , [DABCO](SO3H)2(HSO4)2 , Ionic liquid.