反应详情

温度

-60 °C

Sodium metal (1.8 gm) was reacted under nitrogen atmosphere with ethyl alcohol (40 ml) at room temperature, resulting in a clear solution of sodium ethoxide. A solution of cefuroxime axetil (20.4 gm, S-isomer >90%, R-isomer <10%) in a mixture of tetrahydrofuran (204 ml) and ethyl alcohol (20 ml) was cooled to −60° C. A solution of sodium ethoxide in ethanol was slowly added to this mixture at −60° C. Progress of the reaction was monitored by high pressure liquid chromatography (HPLC). Stirring was continued until cefuroxime axetil almost disappeared (45 minutes). Thereafter, 15% aqueous hydrochloric acid (20 ml) was added and the solvent was evaporated under reduced pressure at low temperature. Water and ethyl acetate (water-immiscible solvent) were added to the reaction mass (basifying agent) and the pH level was adjusted to 6.0 using 5% aqueous potassium bicarbonate solution. The aqueous layer was separated and acidified with 15% aqueous hydrochloric acid to pH 1.0. The resulting solid was filtered, washed with water and dried to yield cefuroxime (15.2 gm).

1. custom(45 minutes)
2. customthe solvent was evaporated under reduced pressure at low temperature
3. additionWater and ethyl acetate (water-immiscible solvent) were added to the reaction mass (basifying agent)
4. customThe aqueous layer was separated
5. filtrationThe resulting solid was filtered
6. washwashed with water
7. customdried