Hydrochloric Acid → 5-(4-chlorophenyl)-4-allyl-2,4-dihydro-3H-1,2,4-triazol-3-one

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Reaction Steps

26.80 g (105.6 mmol) of 2-(4-chlorobenzoyl)-N-allylhydrazinecarboxamide from Example 206A are heated overnight under reflux in 211 ml 3 N aqueous sodium hydroxide. After cooling, it is adjusted to pH 10 with 6 N hydrochloric acid, during which the product almost completely precipitates. The precipitate is suction-filtered, washed with much water and then stirred with methanol. An insoluble white precipitate remains, which is filtered off. The filtrate is concentrated in vacuo and the residue that remains is dried under high vacuum. 21.5 g (86% of theory) of the target compound are thus obtained.

Provenance & Evidence