Acetic Acid → 7-[2-(2-Amino-4-thiazolyl)-2-ethoxyiminoacetamido]-3-cephem-4-carboxylic acid

Participants

Reaction Steps

Palladium on carbon (1.0 g.) moistened with water (3 ml.) was added to a solution of 4-nitrobenzyl 7-[2-(2-amino-4-thiazolyl)-2-ethoxyiminoacetamido]-3-cephem-4-carboxylate (syn isomer, 2.3 g.) in a mixture of tetrahydrofuran (30 ml.), methanol (15 ml.) and acetic acid (0.3 ml.), and the suspension was subjected to catalytic reduction at room temperature under ordinary pressure for 2 hours. After removing the catalyst from the resultant mixture by filtration, the filtrate was concentrated under reduced pressure. Ethyl acetate was added to the residue, and the solution was adjusted to pH 7.5 with an aqueous solution of sodium bicarbonate. After removing the insoluble substance by filtration, the aqueous solution was separated, washed with ethyl acetate, adjusted to pH 5.5 and then treated with activated charcoal. The aqueous solution was adjusted to pH 3.2, and the precipitates were collected by filtration and dried to give 7-[2-(2-amino-4-thiazolyl)--2-ethoxyiminoacetamido]-3-cephem-4-carboxylic acid (syn isomer, 0.6 g.).

Provenance & Evidence