反应详情

To a solution of 7β-[(Z)-2-(2-t-butoxycarbonylaminothiazol-4-yl)-2-trityloxyiminoacetamido]-3-(1-trityl-1,2,3-triazol-4-yl)thiomethylthio-3-cephem-4-carboxylic acid diphenylmethyl ester (29 g: 22.9 mMol.) in a mixture of anisole (50 ml) and nitromethane (200 ml) is added dropwise a solution of aluminum chloride (20.7 g: 156 mMol.) in anisole (50 ml) at -30° to -40° C., and the mixture is stirred for 1 hour at the same temperature. The reaction mixture is diluted with 1N-hydrochloric acid (200 ml) and water, and washed with ethyl acetate. The aqueous layer is concentrated to remove organic solvent under reduced pressure and passed through a column of styrene-divinylbenzene copolymer adsorbent. The product is eluted with aqueous methanol (4:1) to give 7β-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-(1,2,3-triazol-4-yl)thiomethylthio-3-cephem-4-carboxylic acid (8.07 g) as pale yellow powder. Yield: 68%.

1. washwashed with ethyl acetate
2. concentrationThe aqueous layer is concentrated
3. customto remove organic solvent under reduced pressure
4. washThe product is eluted with aqueous methanol (4:1)