Dimethylacetamide → 7beta-[2-(1H-tetrazol-1-yl)acetamido]-3-(3-oxobutyryloxy)methyl-3-cephem-4-carboxylic acid

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Reaction Steps

In dichloromethane (10 ml) was suspended 7β-amino-3-(3-oxobutyryloxy)methyl-3-cephem-4-carboxylic acid (942 mg), followed by the addition of N,N-dimethylacetamide (1 ml). Then, under ice-cooling and stirring, a solution of (1H-tetrazol-1-yl)acetyl chloride (441 mg) in dichloromethane (3 ml) was added. The mixture was further stirred at room temperature for 30 minutes, after which it was poured in an aqueous solution of sodium hydrogen carbonate. The water layer, i.e. aqueous extract, was purified by column-chromatography on Sephadex LH-20. The fractions rich in the desired product were pooled, concentrated, made acidic with phosphoric acid and extracted with ethyl acetate. The extract was dried, concentrated and treated with ether. The procedure provided 7β-[2-(1H-tetrazol-1-yl)acetamido]-3-(3-oxobutyryloxy)methyl-3-cephem-4-carboxylic acid.

Provenance & Evidence