反应详情

42.8 g of ethyl chloroformate are metered into a solution of 60 g of 4-(3-amino-4-chlorophenyl)-4-oxobutyric acid and 27.8 g of triethylamine in 500 ml of tetrahydrofuran in such a way that the temperature does not exceed 10° C. The mixture is stirred in the icebath for a further 10 min and then, while maintaining the cooling, a solution of 35 g of gaseous methylamine in 250 ml of tetrahydrofuran is added, during which a temperature of 25° C. should not be exceeded. After stirring for a further 45 minutes in the icebath, the solvent is removed by distillation, water is added to the residue, and the crystalline precipitate is filtered off. Crystals of melting point 154° C. (from ethanol).

1. customdoes not exceed 10° C
2. temperaturewhile maintaining the cooling
3. stirringAfter stirring for a further 45 minutes in the icebath
4. customthe solvent is removed by distillation, water
5. additionis added to the residue
6. filtrationthe crystalline precipitate is filtered off