H_(14)[NaP_5W_(30)O_(110)]Catalyzed One-Pot Three-Component Synthesis of Dihydropyrano[2,3-c]pyrazole and pyrano[2,3-d]pyrimidine Derivatives

摘要

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 -pheny1-1H-pyrazol-5(411)-one or barbituricacid, aldehydes and malononitrile in the presence of a catalytic amount of preyssler type heteropolyacid as a green and reusablecatalyst in water or ethanol under refluxing conditions.