Efficient one-pot synthetic methods for the preparation of 3,4-dihydropyrimidinones and 1,4-dihydropyridine derivatives using BNPs@SiO2(CH2)(3)NHSO3H as a ligand and metal free acidic heterogeneous nano-catalyst

Heterocyclic compounds with biological and pharmacological activates like 3,4-dihydropyrimidin-2(1H)-ones and 1,4-dihydropyridines have attracted great interest. Boehmite nanoparticles functionalized with silylpropyl sulfamic acid (BNPs@SiO2(CH2)(3)NHSO3H) as a metal free and environmentally friendly catalyst has been found to be effective for the one pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones and the preparation of 1,4-dihydropyridines derivatives. Some features of this protocol are low cost and available materials, short reaction times, convenient catalyst separation, and no need for a neutral atmosphere. Moreover, the catalyst can be reused for at least five times with only a 7% reduction in yield. This study also shows that BNPs@SiO2(CH2)(3)NHSO3H is a sustainable, recoverable and effective heterogeneous catalyst for multicomponent reactions. (C) 2020 Elsevier Ltd. All rights reserved.