Sodium Bicarbonate → 7-[2-(2-Amino-4-thiazolyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid

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Reaction Steps

A solution of 7-[2-(2-amino-4-thiazolyl)glyoxyloylamino]-3-cephem-4-carboxylic acid hydrochloride (1.78 g) in water (100 ml) was adjusted to pH 6.0 with sodium bicarbonate under ice-cooling with stirring. Sodium acetate (0.38 g) and methoxylamine hydrochloride (1.37 g) were added to the solution adjusted to pH 7.0 with sodium bicarbonate and then stirred at 48° C. for an hour. The resultant solution was washed with ethyl acetate (200 ml) and diethyl ether (100 ml) in turn, and then nitrogen gas was bubbled into the solution to remove diethyl ether. The aqueous solution was adjusted to pH 3.5 with 10% hydrochloric acid under ice-cooling with stirring. The precipitates were collected by filtration, washed with water and dried over phosphorus pentoxide under reduced pressure to give 7-[2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 120 mg). The mother liquor was subjected to column chromatography on macroporous, nonionic adsorption resin "Diaion HP-20" (Trademark: manufactured by Mitsubishi Chemical Industries Ltd.) and eluted with 40% aqueous acetone. The eluate was concentrated under reduced pressure, lyophilized, and then dried over phosphorus pentoxide to give the same object compound (950 mg). Total yield 1070 mg.

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