Eco-friendly Synthesis of 1, 4-Dihydropyrano-[2,3-c] Pyrazoles Using Copper Nanoparticles Grafted on Carbon Microsphere as a Heterogeneous Catalyst

A convenient and efficient one-pot three-component synthesis of 6-amino-4-aryl-5-cyano-3-methyl-1-phenyl-1, 4-dihydropyrano[2, 3-c] pyrazoles was achieved using copper nanoparticles grafted on carbon microsphere (Cu-NP/C) as a reusable heterogeneous catalyst. The synthesis of pyranopyarolzes was carried out under mild reaction conditions affording excellent yield of the corresponding products.