one pot regioselective synthesis of new functionalized derivatives of [1, 2, 4] triazolo

Reaction of S-cyano-6-aryl-2-thiouracil 1A-C or its methylthio derivatives 2A-C with hydrazonoyl chlorides 3a-h led to the formation of 7-atyl-6-cyano-1, 2, 4-triazolo [4, 3-alpha] pyrimidin-5 [1H]-one derivatives 8. The mechanism and the regioselectivity of the studied reactions were discussed with the help of the given X-ray crystallographic data