反应详情

7β-Amino-3-(3-oxobutyryloxymethyl)-3-cephem-4-carboxylic acid, 157 g, is suspended in a mixture consisting of 500 ml of tetrahydrofuran and 500 ml of water, and to this, 141 g of sodium hydrogen carbonate is added in small portions with stirring. With stirring at 5° C., 150 g of 2-(2-chloroacetamidothiazol-4-yl)-2(Z)-methoxyiminoacetylchloride hydrochloride is added over 20 minutes, and the reaction mixture is stirred for further 1 hour at the same temperature. After completion of the reaction, the pH is adjusted to 3.0 with 10% hydrochloric acid, and the reaction mixture is extracted twice with 1 liter each of a mixture of ethyl acetate-tetrahydrofuran (1:1). The extract is dried over anhydrous magnesium sulfate, the solvent is evaporated off under reduced pressure to leave colorless powder, which is washed with 200 ml of ethyl acetate and filtered, to give 253 g of the desired compound.

1. stirringWith stirring at 5° C.
2. stirringthe reaction mixture is stirred for further 1 hour at the same temperature
3. customAfter completion of the reaction
4. extractionthe reaction mixture is extracted twice with 1 liter each of a mixture of ethyl acetate-tetrahydrofuran (1:1)
5. dry with materialThe extract is dried over anhydrous magnesium sulfate
6. customthe solvent is evaporated off under reduced pressure
7. customto leave colorless powder, which
8. washis washed with 200 ml of ethyl acetate
9. filtrationfiltered