反应详情

Acetic acid (4 ml) and zinc powder (3 g) were added under stirring and ice-cooling to a solution of 2,2,2-trichloroethyl 2-methyl-7-(2-cyanoacetamido)-3-cephem-4-carboxylate (3.2 g) in anhydrous dimethylformamide (15 ml), and the mixture was stirred for 1 hour at the same temperature. After the reaction, ethyl acetate (100 ml) was added to the reaction mixture. The insoluble material was filtered off, and the filtrate was washed with 5% hydrochloric acid saturated with sodium chloride, and then extracted with a saturated sodium bicarbonate aqueous solution. The extract was acidified with 10% hydrochloric acid and extracted with ethyl acetate. The extract was washed with a saturated sodium chloride aqueous solution and dried over magnesium sulfate. After the solvent was distilled off, the crystalline residue was recrystallized from a mixture of ethyl acetate and benzene to give 2-methyl-7-(2-cyanoacetamido)-3-cephem-4-carboxylic acid (2.3 g), mp 162° to 166° C.

1. stirringthe mixture was stirred for 1 hour at the same temperature
2. additionwas added to the reaction mixture
3. filtrationThe insoluble material was filtered off
4. washthe filtrate was washed with 5% hydrochloric acid saturated with sodium chloride
5. extractionextracted with a saturated sodium bicarbonate aqueous solution
6. extractionextracted with ethyl acetate
7. washThe extract was washed with a saturated sodium chloride aqueous solution
8. dry with materialdried over magnesium sulfate
9. distillationAfter the solvent was distilled off
10. customthe crystalline residue was recrystallized from a mixture of ethyl acetate and benzene