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

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Reaction Steps

An amount of 26.8 g (106 mmol) of 2-[(4-chlorophenyl)carbonyl]-N-(prop-2-en-1-yl)hydrazinecarboxamide from Example 1A was suspended in 210 ml of 3M sodium hydroxide solution and heated under reflux for 20 hours. After cooling, a pH of 10 was set using half-concentrated hydrochloric acid. The colourless solid precipitated was isolated by suction filtration, washed to neutrality with water and then stirred up in methanol. The mixture was freed from insoluble constituents by filtration, the filtrate was concentrated under reduced pressure on a rotary evaporator and the residue was dried in a high vacuum. This gave 21.5 g (86.4% of theory) of the desired compound as a solid.

Provenance & Evidence