Phosphoric Acid → 7beta-phenylacetamido-3-(1-methyl-1H-tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid

Beteiligte Stoffe

Reaktionsschritte

In water (50 ml) is suspended 7β-phenylacetamido-3-[2-(N-carboethoxysulfamoyl)benzoyloxy]methyl-3-cephem-4-carboxylic acid (3.0 g) together with 5-mercapto-1-methyl-1H-tetrazole (1.0 g). The mixture is adjusted to pH 5.5 with sodium hydrogen carbonate and the resultant solution is heated at 60° C. for 50 minutes. The solution is brought to pH 2.0 with dilute phosphoric acid and extracted with ethyl acetate (100 ml). The extract is rinsed with a saturated aqueous solution of sodium chloride, dried and concentrated. Then, following the addition of ether, the precipitate is recovered by filtration. By the above procedure is obtained 7β-phenylacetamido-3-(1-methyl-1H-tetrazol-5-yl) thiomethyl-3-cephem-4-carboxylic acid (1.8 g).

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