反应详情

To a solution of 7β-[(Z)-2-(2-t-butoxycarbonylaminothiazol-4-yl)-2-trityloxyiminoacetamido]-3-(1-methyl-1,2,3-triazol-4-yl)thiomethylthio-3-cephem-4-carboxylic acid diphenylmethyl ester (708 mg: 0.683 mMol.) in a mixture of anisole (2 ml) and nitromethane (8 ml) is added dropwise a solution of aluminum chloride (727 mg: 5.47 mMol.) in anisole (2 ml) at -40° C., and the mixture is stirred for 1 hour at -30°--40° C. The reaction mixture is diluted with 1N-hydrochloric acid (5.5 ml) and water and washed with ethyl acetate. The aqueous layer is concentrated under reduced pressure to remove organic solvent and passed through a column of styrene-divinylbenzene copolymer adsorbent. The product is eluted with methanol-water (4:1) to give 7β-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-3-(1-methyl-1,2,3-triazol-4-yl)thiomethylthio-3-cephem-4carboxylic acid as pale yellow powder (96.3 mg). Yield: 27%.

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