Hydrochloric Acid → Cefuroxime

Beteiligte Stoffe

Reaktionsschritte

A solution of (6R,7R)-7-[Z-2-(fur-2-yl)-2-methoxyiminoacetamido]-3-hydroxymethylceph-3-em-4-carboxylic acid (3.81 g) in dioxan (20 ml) was added over ca. 1 minute to a stirred solution of dichlorophosphinyl isocyanate (1.46 ml) in 1,2-dichloroethane (30 ml) at 19°, the temperature rising to 28°. The resulting solution was stirred for 15 minutes and then added to a solution of NaHCO3 (5.1 g) in water (70 ml). This mixture was stirred at ca. 30° for 1 hour, and then heated at 40° to 45° for a total of 4.5 hours, the pH being adjusted to 5.0 with hydrochloric acid after 3 hours. The two-phase mixture was adjusted from pH 5.8 to 7.0 with aqueous NaHCO3 solution and the aqueous phase was washed with 1,2-dichloroethane (20 ml) and ethyl acetate (50 ml), and acidified to pH 1.9 with dilute hydrochloric acid in the presence of ethyl acetate. The aqueous phase was re-extracted with ethyl acetate, and the combined ethyl acetate extract washed with 25% aqueous sodium chloride solution and evaporated. The solid residue was slurried with diethyl ether to give the title compound (3.18 g, 75.0%); purity by HPLC 91.6% and by TLC 89.5%.

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