反应详情

To a suspension of 2-methyl-7-[2-methoxyimino-2-(2-formylaminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), which can be represented as 2-methyl-7-[2-methoxyimino-2-(2-formylimino-2,3-dihydrothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer), (9.0 g.) in methanol (90 ml.) was added concentrated hydrochloric acid (2.12 ml.) with stirring at room temperature, and the mixture was stirred for 7 hours at the same temperature. To the reaction mixture was gradually added diethyl ether till crystals started to precipitate. The mixture was allowed to stand for 30 minutes, and the precipitated crystals were collected by filtration, washed with diethyl ether and then dried to give white crystals of 2-methyl-7-[2-methoxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid hydrochloride (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 hydrochloride (syn isomer), (7.9 g.) The remaining filtrate was concentrated till the total volume became half. To the concentrated filtrate was gradually added diethyl ether till crystals started to precipitate, and the mixture was allowed to stand for 1 hour. The precipitated crystals were collected by filtration, washed with diethyl ether and then dried to give further the same object compound (0.5 g.).

1. stirringthe mixture was stirred for 7 hours at the same temperature
2. customto precipitate
3. filtrationthe precipitated crystals were collected by filtration
4. washwashed with diethyl ether
5. customdried