反应详情

To a solution of benzyl 7β-amino-3-methyl-3-cephem-4-carboxylate (1.2 g) and anisole (5.2 ml) in methylene chloride (100 ml) is dropwise added a solution of aluminum chloride (3.11 g) in nitromethane (40 ml) under ice cooling, and the mixture stirred for 4.5 hours at room temperature, mixed with water (40 ml), and adjusted to pH 0.3 with 1 N-hydrochloric acid. The aqueous layer is separated, washed with ethyl acetate (30 ml), adjusted to pH 2.4 with an aqueous solution of sodium hydroxide and allowed to stand overnight at 0° C. The resulting crystals are collected by filtration to give 7β-amino-3-methyl-3-cephem-4-carboxylic acid (757 mg). Yield: 89.6%. This product was identical with an authentic specimen in NMR and IR spectra.

1. customThe aqueous layer is separated
2. washwashed with ethyl acetate (30 ml)
3. waitto stand overnight at 0° C
4. filtrationThe resulting crystals are collected by filtration