Boric Acid/Pentaerythritol as a Green and Reusable Catalytic System for the Synthesis of Mono- and Bis-Pyrano[2,3-d]Pyrimidinone Derivatives in Water

Boric acid and pentaerythritol as a green and reusable catalytic system efficiently catalyzed the one-pot three-component synthesis of mono- and bis-pyrano[2,3-d]pyrimidinones, bis-alkylidene malononitriles, as well as spirooxindoles from the various aromatic aldehydes/isatins, malononitrile, and barbituric acid in water. Being environmentally friendly, reusability, short reaction times, high yields, low cost, commercial availability of the starting materials, and easy work-up are attractive features of the present work. 10 new compounds were synthesized in similar conditions reactions in high yields.