反应详情

温度

40 °C

A mixture of ampicillin Dane potassium salt (45.6 g), 1-bromoethyl ethyl carbonate (36.0 g), sodium bicarbonate (38.4 g) and acetonitrile (260 ml) is stirred for 3 hours at 40° C. The mixture is filtered and the cake is washed with acetonitrile (2×20 ml). Water (20 ml) is added and the mixture is stirred for 1 hour. Most of the solvent is removed by evaporation at 35°-40° C., under reduced pressure. Acetone (70 ml) and water (4.5 ml) are added. A mixture of concentrated hydrochloric acid (6.85 ml) and water (2.3 ml) is added slowly in order to keep the pH at 2-2.5. If, at the end, the pH is not stable, a small additional amount of 1:1 hydrochloric acid is added until a stable pH in the range 2-2.5 is obtained. The solution is dried and filtered. Butyl acetate (180 ml) and the solution is distilled under reduced pressure to a volume of ca. 40 ml. More butyl acetate (270 ml) is added and the product is allowed to crystallize at ca. 5° C. The mixture is filtered to give 32.5 g bacampicillin.

1. filtrationThe mixture is filtered
2. washthe cake is washed with acetonitrile (2×20 ml)
3. additionWater (20 ml) is added
4. stirringthe mixture is stirred for 1 hour
5. customMost of the solvent is removed by evaporation at 35°-40° C., under reduced pressure
6. additionAcetone (70 ml) and water (4.5 ml) are added
7. additionA mixture of concentrated hydrochloric acid (6.85 ml) and water (2.3 ml)
8. additionis added slowly in order
9. additiona small additional amount of 1:1 hydrochloric acid is added until a stable pH in the range 2-2.5
10. customis obtained
11. customThe solution is dried
12. filtrationfiltered
13. distillationButyl acetate (180 ml) and the solution is distilled under reduced pressure to a volume of ca. 40 ml
14. additionMore butyl acetate (270 ml) is added
15. customto crystallize at ca. 5° C
16. filtrationThe mixture is filtered