4-Nitrobenzyl 7-[2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetamido]-3-cephem-4-carboxylate → 7-[2-(2-Amino-4-thiazolyl)-2-hydroxyiminoacetamido]-3-cephem-4-carboxylic acid

Participants

Reaction Steps

10% Palladium carbon (0.35 g.) was added to a solution of 4-nitrobenzyl 7-[2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetamido]-3-cephem-4-carboxylate (syn isomer: 0.7 g.) in methanol (70 ml.), and the mixture was subjected to catalytic reduction at room temperature under atmospheric pressure for 1.5 hours. The resultant mixture was filtered, and the filtrate was concentrated under reduced pressure. To the residue was added an aqueous solution of sodium bicarbonate and the insoluble substance was filtered out. The filtrate was washed with ethyl acetate and methylene chloride in turn, bubbled with nitrogen gas and then lyophilized. The residue was dissolved in water (30 ml.) and adjusted to pH 3.8 with 10% hydrochloric acid. The solution was subjected to column chromatography on macroporous, nonionic adsorption resin "Diaion HP-20" (Trade mark; manufactured by Mitsubishi Chemical Industries, Ltd., 20 ml.), washed with water, and then eluted with 40% aqueous acetone. After acetone was removed from the eluate under reduced pressure, the residue was lyophilized to give 7-[2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetamido]-3-cephem-4-carboxylic acid (syn-isomer: 0.25 g.)

Provenance & Evidence