反应详情

284.3 g of 5-ethyl-5-methyl-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 for 25 hours at 90° C to 107° C internal temperature (external temperature: 160° C), in the manner described under Example 1 (a). 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 waterpump 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 are purified by vacuum distillation (boiling point0.2 : 147° C). Yield of pure product: 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 waterpump vacuum
4. customThe reaction mixture is then dried to constant weight at 90° C
5. custom392.5 g of a brown, clear, product (95.9% of theory) are obtained
6. distillationare purified by vacuum distillation (boiling point0.2 : 147° C)
7. customA sample recrystallised from diethyl ether melts at 58.0° C to 59.0° C.