An experimental and theoretical study on bicyclo-3,4-dihydropyrimidinone derivative: synthesis and DFT calculation

We report here an efficient and green method for fused Biginelli condensation reaction of aldehydes, cyclopentanone, and urea by using nano ZrO2-SO3H as catalyst under solvent-free conditions. The prospect of the reusability of this catalyst has also been demonstrated without compromising on the yield of the product. On the whole, the protocol presented here is an excellent alternative to many of the reported procedures by the use of nano ZrO2-SO3H as recyclable catalyst. So, Optimized molecular structures have been investigated by DFT/B3LYP method with 6-31G (d,p) basis set. Stability of some 4-aryl-7-benzylidene-1,3,4,5,6,7-hexahydro-4-phenyl-2H-cyclopenta[d]pyrimidin-2-one (2 a-j) derivatives and intramolecular interactions bond has been analyzed by using natural bond orbital (NBO) analysis.