反应详情

To a solution of 3-(1,3,4-thiadiazol-2-yl)thiomethyl)-7-[2-(2-tert-pentyloxycarbonylamino-1,3-thiazol4-yl)glyoxylamido]-3-cephem-4-carboxylic acid, which can be represented as 3-(1,3,4-thiadiazol-2-yl)thiomethyl-7-[2-(2-tert-pentyloxycarbonylimino-2,3-dihydro-1,3-thiazol-4-yl)glyoxylamido]-3-cephem-4-carboxylic acid, (3.1 g.) in methanol (30 ml.) was added 1 N sodium hydroxide aqueous solution (5.2 ml.) under ice-cooling and stirring. To the mixture was dropwise added a solution of sodium borohydride (0.074 g.) in water (2 ml.) over 10 minutes, and the mixture was stirred for 30 minutes at the same temperature. After the reaction, the reaction mixture was concentrated under reduced pressure. To the residue were added water and ethyl acetate, and the aqueous layer was separated. The aqueous layer was adjusted to pH 5 to 6 with 10% hydrochloric acid and then washed with ethyl acetate. To the aqueous layer was added ethyl acetate, and the mixture was adjusted to pH 1 to 2 with 10% hydrochloric acid. The ethyl acetate layer was separated, washed with water, dried over magnesium sulfate and then treated with activated charcoal. After distillation of the solvent from the ethyl acetate layer, the remaining residue was pulverized in diethyl ether, collected by filtration and then dried to give pale yellow powder of 3-(1,3,4-thiadiazol-2-yl)thiomethyl-7-[2-hydroxy-2-(2-tert-pentyloxycarbonylamino-1,3-thiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid, which can be represented as 3-(1,3,4-thiadiazol-2-yl)thiomethyl-7-[2-hydroxy-2-(2-tert-pentyloxycarbonylimino-2,3-dihydro-1,3-thiazol-4-yl)acetamido]-3-cephem-4-carboxylic acidc (2.2 g.).

1. temperaturecooling
2. stirringthe mixture was stirred for 30 minutes at the same temperature
3. customAfter the reaction
4. concentrationthe reaction mixture was concentrated under reduced pressure
5. additionTo the residue were added water and ethyl acetate
6. customthe aqueous layer was separated
7. washwashed with ethyl acetate
8. additionTo the aqueous layer was added ethyl acetate
9. customThe ethyl acetate layer was separated
10. washwashed with water
11. dry with materialdried over magnesium sulfate
12. additiontreated with activated charcoal
13. distillationAfter distillation of the solvent from the ethyl acetate layer
14. filtrationcollected by filtration
15. customdried