反应详情

14.0 g of 3-benzyloxy-4-methoxybenzoyl chloride are added in one portion at 26° C. to 15.6 g of 4-aminobutyric acid, 12.1 g of sodium hydroxide and 160 ml of ion-free water and subsequently 30 ml of tetrahydrofuran are added dropwise within 10 minutes. After 2 hours, the mixture is acidified with concentrated hydrochloric acid at a temperature below 10° C. The precipitate is separated and stirred with ethyl acetate. The mixture is filtered and the filter cake is washed with ethyl acetate. There is obtained 4-[(3-benzyloxy-4-methoxybenzoyl)amino]butyric acid which, after recrystallisation from ethyl acetate, melts at 156°-158° C.

1. additionare added dropwise within 10 minutes
2. customThe precipitate is separated
3. filtrationThe mixture is filtered
4. washthe filter cake is washed with ethyl acetate