| 摘要 |
<p>New process for the preparation of 1,2,4-triazol-3-ones of formula: <IMAGE> in which R<1> denotes an aliphatic, cycloaliphatic, phenyl, naphthyl or heterocyclic radical, R<2> denotes a hydrogen atom or an aliphatic, cycloaliphatic, phenyl, naphthyl or heterocyclic radical, and R<3> denotes a hydrogen atom or a substituted alkyl, phenyl or naphthyl radical, which consists in reacting a monoacylhydrazine with phosgene to obtain a 1,3,4-oxadiazolin-2-one which is reacted with a compound of formula R<2>NH2 to obtain an acylsemicarbazide and in cyclising the latter by treatment with alkali. 1,2,4-Triazol-3-ones are very useful as intermediates in the manufacture of medications, herbicides and polymers.</p> |
