Regioselective addtion of 5-amino-3-benzylthio-l,2,4-triazole and its analogues with aryl isocyanates

(整期优先)网络出版时间:1997-06-16
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Theorientationoftheadditionof5-amino-3-benzylthio-1,2,4-triazoleanditsanalogues(pyrazole)(1)withthearylisocyanatecanbedirectedbycontrollingthereactiontemperatureandoneoftheproduct,5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole(pyrazole)(2),canrearrangeat170Ctoanotherproduct,5-arylureylene-3-benzylthio-1,2,4-triazole(pyrazole)(3).Aplausiblemechanismexplanationforthisrearrangementreactionwaspresented.Itwassuggestedthattherearrangementreactioncouldbereferredtothethermodynamicstranspositionleadingtothepredominant5-arylureylene-3-benzylthio-1,2,4-triazoleenergypreferentially.