反应详情

Phosphorus pentachloride (5.83 g, 28 mmol) was made a methylene chloride (50 ml) suspension, pyridine (7.39 g, 93 mmol) was added at 5°-10° C. and stirring was continued for 40 minutes. Added all at once at 5° C. thereto was benzhydryl 7-phenylacetamido-3-[2-(4-methyl-1,2,3-thiadiazol-5-yl)vinyl]-3-cephem-4-carboxylate (E/Z=1/3.5, 5.69 g, 9.36 mmol), and the mixture was stirred at the same temperature for 3 hours. Methanol (38 ml) was slowly added to the reaction mixture at -50° C., and it was stirred for 1 hour at -50° to -30° C. Water (7 ml) was added at -10° C. and the reaction temperature was set at 0° C. and then it was stirred for 10 minutes. The reaction solution was adjusted to pH 6 with saturated sodium bicarbonate solution and then extracted with methylene chloride. It was washed with water and then the methylene chloride layer was dried over magnesium sulfate. The solvent was distilled off and then ethyl acetate was added to the residue. Precipitates were filtered and then cleansed with ethyl acetate thereby benzhydryl 7-amino-3-[(Z)-2-(4-methyl-1,2,3-thiadiazol-5-yl)vinyl]-3-cephem-4-carboxylate (2.06 g, 45% yield) was obtained.

1. additionwas added at 5°-10° C.
2. additionAdded all at once at 5° C.
3. stirringthe mixture was stirred at the same temperature for 3 hours
4. stirringit was stirred for 1 hour at -50° to -30° C
5. customwas set at 0° C.
6. stirringit was stirred for 10 minutes
7. extractionextracted with methylene chloride
8. washIt was washed with water
9. dry with materialthe methylene chloride layer was dried over magnesium sulfate
10. distillationThe solvent was distilled off
11. additionethyl acetate was added to the residue
12. customPrecipitates
13. filtrationwere filtered