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

Participants

Reaction Steps

26.8 g (106 mmol) of 2-[(4-chlorophenyl)carbonyl]-N-(prop-2-en-1-yl)hydrazinecarboxamide from Example 11A were suspended in 210 ml of 3 M aqueous sodium hydroxide solution, and the mixture was heated under reflux for 20 h. After cooling, the pH was adjusted to 10 using semiconcentrated hydrochloric acid. The precipitated colorless solid was filtered off with suction, washed with water until neutral and then stirred with methanol. By filtration, the mixture was freed from insoluble components, the filtrate was concentrated under reduced pressure on a rotary evaporator and the residue was dried under high vacuum. This gave 21.5 g (86.4% of theory) of the title compound as a colorless solid.

Provenance & Evidence