Facile Regioselective Green Synthesis of Triazolo [4,3-a] Pyrimidines in Aqueous Medium

Regioselectivity is investigated in multi-component reaction of amino triazole, carbonyl compounds and α- cyano esters derivative and exclusive synthesis of triazolopyrimidines is developed in aqueous medium in excellent yields in shorter period using microwaves or ultrasonic waves. Path and mechanism of the reaction has also been discussed. The operational simplicity, environmental friendly conditions, regioselective formation of target product, high yield in significantly very short reaction time, are major benefits.