p-Nitrobenzyl 7-{2-(1,2,3-thiadiazol-4-yl)-2-methoxyiminoacetamido}-3-cephem-4-carboxylate → 7-{2-(1,2,3-Thiadiazol-4-yl)-2-methoxyiminoacetamido}-3-cephem-4-carboxylic acid

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Reaction Steps

10% Palladium carbon (0.85 g.) was added to a solution of p-nitrobenzyl 7-{2-(1,2,3-thiadiazol-4-yl)-2-methoxyiminoacetamido}-3-cephem-4-carboxylate (syn isomer, 1.65 g.) in methanol (70 ml.) and tetrahydrofuran (90 ml.), and the mixture was subjected to catalytic reduction at room temperature under atmospheric pressure for 3.5 hours. After removing the catalyst from the reaction mixture by filtration, the filtrate was concentrated under reduced pressure. Water was added to the residue, and the mixture was adjusted to pH 7 to 8 with sodium bicarbonate, washed with ethyl acetate, adjusted to pH 1.5 with 10% hydrochloric acid, and then extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate, and then filtered. The filtrate was concentrated under reduced pressure, and the residue was pulverized with diethyl ether. The precipitates were collected by filtration and the dried to give yellow powder of 7-{2-(1,2,3-thiadiazol-4-yl)-2-methoxyiminoacetamido}-3-cephem- 4-carboxylic acid (syn isomer, 0.3 g.), m.p. 200° to 210° C. (dec.).

Provenance & Evidence