Hydrochloric Acid → 7-[2-(2-Aminothiazol-4-yl)-2-n-butoxyiminoacetamido]-3-cephem-4-carboxylic acid

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Reaction Steps

A mixture of 7-[2-(2-formamidothiazol-4-yl)-2-n-butoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 12.7 g.), conc. hydrochloric acid (9.6 ml.), methanol (9.5 ml.) and tetrahydrofuran (9.5 ml.) was stirred at room temperature for 3 hours. The resultant solution was concentrated in vacuo, and the residue was suspended in water. The suspension was adjusted to pH 3.5 with sodium bicarbonate under ice cooling, and stirred at same temperature for 30 minutes. The precipitates were collected by filtration and dried over magnesium sulfate to give the powder (10 g.). The powder was suspended in water (300 ml.) and adjusted to pH 7.0 with sodium bicarbonate. The solution was adjusted to pH 6.0 with 10% hydrochloric acid and subjected to column chromatography on nonionic adsorption resin (Diaion HP-20: trademark, manufactured by Mitsubishi Chemical Industries Ltd.) (300 ml.) with 10% aqueous solution of isopropyl alcohol. The eluate was adjusted to pH 3.5 with 10% hydrochloric acid under ice cooling, and the precipitates were collected by filtration, washed with water and dried to give 7-[2-(2-aminothiazol-4-yl)-2-n-butoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 7.2 g.).

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