反应详情

284.3 g of 5-methyl-5-ethyl-hydantoin (2.0 mols), 138.2 g of anhydrous potassium carbonate (1.0 mol), 791.7 g of 1,2-dichloroethane (8.0 mols) and 230 ml of dimethylformamide are subjected to an azeotropic circulatory distillation, analogously to A, for 25 hours at 90°C to 107°C internal temperature (external temperature: 160°C). After completion of the reaction, the mixture is filtered whilst still hot and the filtrate is concentrated on a rotary evaporator at 90°C under a water pump vacuum. The reaction mixture is then dried to constant weight at 90°C and 10-1 mm Hg. 392.5 g. of a brown, clear product (95.9% of theory) are obtained, and purified by vacuum distillation (boiling point0.2 : 147°C). Yield of pure material: 327.3 g (80% of theory). A sample recrystallised from diethyl ether melts at 58.0°C to 59.0°C.

1. customAfter completion of the reaction
2. filtrationthe mixture is filtered whilst still hot and the filtrate
3. concentrationis concentrated on a rotary evaporator at 90°C under a water pump vacuum
4. customThe reaction mixture is then dried to constant weight at 90°C
5. customof a brown, clear product (95.9% of theory) are obtained
6. distillationpurified by vacuum distillation (boiling point0.2 : 147°C)
7. customA sample recrystallised from diethyl ether melts at 58.0°C to 59.0°C.