反应详情

The crude 4-(3',5'-difluorobenzyl)-1-formyl-3-thiosemicarbazide (3.5 g) was refluxed overnight in a solution of sodium ethoxide (from sodium (0.3 g) in ethanol (25 ml.)). The reaction was filtered, evaporated to dryness, and diluted with water. The aqueous solution was acidified to pH 3-4 with 10% hydrochloric acid, and the precipitate was collected by filtration and recrystallized from ethanol-water to yield 2.3 g (71%) of 4-(3',5'-difluorobenzyl)-1,2,4-triazole-3-thiol after recrystallization from water, m.p.: 129°-130° C.

1. filtrationThe reaction was filtered
2. customevaporated to dryness
3. additiondiluted with water
4. filtrationthe precipitate was collected by filtration
5. customrecrystallized from ethanol-water