Oxalyl chloride → 3-(1-Pyridinio)methyl-3-cephem-4-carboxylate

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Reaction Steps

0.57 g of oxalyl chloride is added at -5° to 0° C. to 15 ml of chloroform containing 0.35 g of dimethylformamide, and the mixture is stirred at the same temperature for 15 minutes. A mixture of 1.54 g of (Z)-2-(2-tritylaminothiazol-4-yl)-2-[(2-pyrrolidon-3-yl)oxyimino]acetic acid, 0.3 g of triethylamine and 15 ml of chloroform is added to said mixture at -30° to -35° C., and the mixture is further stirred at the same temperature for 5 minutes. Then, a solution of 7β-amino-3-(1-pyridinio-methyl)-3-cephem-4-carboxylate in chloroform (said solution is prepared by suspending 1.82 g of the dihydrochloride of said cephem compound in 10 ml of chloroform and adding 4 ml of N,O-bis(trimethylsilyl)acetamide thereto to dissolve said salt therein) is added to said mixture at -35° to -30° C., and the mixture is stirred at the same temperature for 10 minutes and at -30° to -10° C. for one hour. The mixture is concentrated to dryness under reduced pressure. 60 ml of 80% aqueous formic acid are added to the residue, and the aqueous mixture is stirred at room temperature for one hour. 50 ml of water are added to said aqueous mixture. Then, insoluble materials are filtered off, and the filtrate is washed with ethyl acetate and concentrated to dryness under reduced pressure. The residue thus obtained is dissolved in water and chromatographed on a column of non-ionic polymer resin Diaion HP-20 (registered trade mark, manufactured by Mitsubishi Chemical Industries Ltd., Japan). The column is washed with water, followed by elution with 20% methanol. The fractions containing the cephalosporin compound are collected and concentrated to dryness under reduced pressure. Acetone is added to the residue thus obtained, and the resulting powder is collected by filtration. 0.84 g of 7β-{)(Z)-2-(2-aminothiazol-4-yl)-2- [(2-pyrrolidon-3-yl)oxyimino]acetamido}-3-(1-pyridiniomethyl)-3-cephem-4-carboxylate is obtained.

Provenance & Evidence