反应详情

To a stirred solution of 12.9 g (0.10 mole) of ethyl 3-aminocrotonate in 50 ml of anhydrous dimethylformamide is added during 10 min. 15.36 g (0.10 mole) of p-chlorophenyl isocyanate in 50 ml of the same solvent. A mild exotherm (5° C.) results. After stirring for 3 hours, the reaction solution is slowly added with stirring to 1.5 l of deionized water. The white solid product is collected by vacuum filtration, washed with water and air dried at 45°-55° to give 23 g of ethyl 3-amino-2-(4-chlorophenylcarbamoyl)crotonate. Recrystallization of a 2.0 g. portion of this material from 15 ml of ethanol gives 1.5 g of pure ethyl 3-amino-2-(4-chlorophenylcarbamoyl)crotonate.

1. customA mild exotherm (5° C.) results
2. additionthe reaction solution is slowly added
3. filtrationThe white solid product is collected by vacuum filtration
4. washwashed with water and air
5. customdried at 45°-55°