Abstract
A convenient one-pot, three-component reaction of aromatic aldehydes, 6-amino-1,3-dimethyluracil and active methylene compounds in the presence of Zr(HSO4)4 as a heterogeneous catalyst, under solvent-free conditions brings a very simple and highly efficient method for the preparation of pyrimido[4,5-b]quinolines, pyrimido[5',4':5,6]pyrido[2,3- d]pyrimidines, indeno[2',1':5,6]pyrido[2,3-d]pyrimidines and a new class of pyrimidinedione derivatives in excellent yields. This approach is general and provides several advantages such as simple reaction set-up, very mild reaction conditions, high yields, recyclability of the catalyst and environmentally friendly benign.
Keywords: 6-Amino-1, 3-dimethyluracil, Solvent-free, Tandem Knoevenagel-Michael addition, Zr(HSO4)4.