Three-Component Reaction to Form 1,4-Dihydropyrano[2,3-c]pyrazol-5-yl Cyanides

The three-component reactions of 3-alkyl-1-phenyl-2-pyrazolin-5-ones, aryl aldehydes, and malononitrile in the presence of base catalysts such as sodium acetate, triethylamine, and magnesium oxide (MgO) are investigated. Magnesium oxide (MgO) effectively catalyzes these reactions to form 1,4-dihydropyrano[2,3-c]pyrazol-5-yl cyanide derivatives. The salient features of this method include high conversions, short reaction times, cleaner reaction profiles, and the use of inexpensive and readily available catalyst.