Hydrazinecarboxaldehyde → Ethyl (3-formyltriazan-1-ylidene)acetate

関与物質

反応手順

In Latvijas PSR Zinatnu Akad. Vestis, Khim. Ser., (2), 204-208(1965), there is described obtaining 1,2,4-triazole-3-carboxamide starting from acetyl chloride through the six reaction steps described below: ##STR3## In Czechoslovakia Pat. No. 175,118, there is disclosed a process for preparing ethyl ester of 1,2,4-triazole-3-carboxylic acid, in which ethyl ester of thioxamide acid and formylhydrazine are subjected to reaction with each other at 50° to 60° C. to obtain ethyl (2-formylhydrazino)iminoacetate, which is then heated at 160° C. to form a closed ring by dehydration. Since ethyl ester of thioxamide acid can be synthesized by subjecting ethyl ester of oxamide acid, which is available from a reaction between ethyl oxalate and ammonia, to reaction with phosphorus pentasulfide,1,2,4-triazole-3-carboxamide can be prepared from an oxalate through the five reaction steps described below. ##STR4## In this case, hydrogen sulfide is formed as a by-product and a complicated apparatus is required for deodorization thereof.

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