Hydrochloric Acid → 2-Methyl-7-[2-methoxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid

Participants

Reaction Steps

To a solution of sodium acetate (11.6 g.) in water (43 ml) was added 2-methyl-7-[2-methoxyimino-2-(2-trifluoroacetylaminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), which can be represented as 2-methyl-7-[2-methoxyimino-2-(2-trifluoroacetylimino-2,3-dihydrothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), (2.1 g.) with stirring, and the mixture was adjusted to pH 6 with 5% aqueous sodium bicarbonate solution. The mixture was stirred overnight at room temperature. After the reaction, the reaction mixture was adjusted to pH 2.8 to 3 with 10% hydrochloric acid and then cooled. The precipitates were collected by filtration and then dried to give 2-methyl-7-[2-methoxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), which can be represented as 2-methyl-7-[2-methoxyimino-2-(2-imino-2,3-dihydrothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), (1.1 g.), dp>241° C. The same object compound (0.25 g.) was further obtained from the filtrate by a conventional manner.

Provenance & Evidence