Facile one-pot synthesis of pyrido[2,3-d]pyrimidine derivatives over ZrO2 nanoparticles catalyst

An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel–Michael addition of aromatic aldehydes, methylcyanoacetate and 4(6)-aminouracil in solvent-free conditions in the presence of 10 mol% of ZrO2 nanoparticles (ZrO2 NPs) as a heterogenous catalyst. The procedure is formed in high yields, short reaction time and an environmentally friendly specificity.