H14[NaP5W30O110] Catalyzed One-Pot Three-Component Synthesis of Dihydropyrano[2,3-c]pyrazole and pyrano[2,3-d]pyrimidine Derivatives

This is a report of an efficient, clean and facile method for the synthesis of 1,4-dihydropyrano[2,3-c] pyrazole and pyrano[2,3-d]pyrimidine derivatives via three-component one-pot condensation of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one or barbituric acid, aldehydes and malononitrile in the presence of a catalytic amount of preyssler type heteropolyacid as a green and reusable catalyst in water or ethanol under refluxing conditions