反应详情

2,2-Dimethoxyethyl isothiocyanate (37.7 g) is added in the course of 1 hour to a solution of hydrazine hydrate (14.35 g) in ethanol (40 cc), whilst stirring at a temperature of between 5 and 9° C. After 12 hours at 4° C., the mixture is concentrated to dryness at 20° C. under reduced pressure (20 mm Hg; 2.7 kPa). The yellow syrup obtained crystallises after seeding. The solid is dissolved in hot methanol (50 cc) and the solution is filtered and diluted with diethyl ether (200 cc). After about ten hours at 4° C., the mixture is filtered and 4-(2,2-dimethoxyethyl)-thiosemicarbazide (32.3 g) is obtained in the form of a white solid.

1. concentrationthe mixture is concentrated to dryness at 20° C. under reduced pressure (20 mm Hg; 2.7 kPa)
2. customThe yellow syrup obtained
3. customcrystallises
4. dissolutionThe solid is dissolved in hot methanol (50 cc)
5. filtrationthe solution is filtered
6. additiondiluted with diethyl ether (200 cc)
7. waitAfter about ten hours at 4° C.
8. filtrationthe mixture is filtered