反应详情

A suspension of 2,2,2-trichloroethyl-2-methyl-7-amino-3-cephem-4-carboxylate hydrochloride (6.9 g) in dried dichloromethane (70 ml) was homogenized by adding triethylamine (1.48 g) and N,N-dimethylaniline (0.44 g) under stirring and ice-cooling and by stirring for 30 minutes at room temperature. A solution of triethylamine salt of mixed anhydride of 2-sulfo-2-phenylacetic acid with ethoxycarbonic acid (8.5 g) in dried dichloromethane (60 ml) was dropwise added over about 30 minutes under stirring and cooling at -20° to -25° C. to the above-mentioned solution, and the mixture was stirred for 1.5 hours at -10° to -15° C. and for 1 hour at room temperature. After the reaction, dichloromethane was removed at low temperature, and the residue was dissolved in ethyl acetate, after which the solution was washed with cooled 5% hydrochloric acid and three times with water, and then dried. The solvent was distilled off at low temperature to give 2,2,2-trichloroethyl 2-methyl-7-(2-sulfo-2-phenylacetamido)-3-cephem-4-carboxylate (11.5 g), amorphous.

1. stirringunder stirring
2. temperatureice-cooling
3. stirringby stirring for 30 minutes at room temperature
4. stirringunder stirring
5. temperaturecooling at -20° to -25° C. to the above-mentioned solution
6. stirringthe mixture was stirred for 1.5 hours at -10° to -15° C. and for 1 hour at room temperature
7. customwas removed at low temperature
8. dissolutionthe residue was dissolved in ethyl acetate
9. washafter which the solution was washed
10. temperaturewith cooled 5% hydrochloric acid and three times with water
11. customdried
12. distillationThe solvent was distilled off at low temperature