Phosphorus oxychloride → HCID 131712596, compound

Participants

Reaction Steps

The Vilsmeier reagent was prepared from dry dimethylformamide (0.667 g.), phosphorus oxychloride (1.40 g.) and dry ethyl acetate (4 ml.) by the conventional method. Dry ethyl acetate (16 ml.) was added thereto and then 2-t-butoxycarbonylmethoxyimino-2-(2-formamidothiazol-4-yl)acetic acid (syn isomer) (2 g.) was added thereto at 0° C. The mixture was stirred for 30 minutes at the same temperature. The resulting mixture was added dropwise at -15° C. to a stirred solution of 7-amino-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (3.01 g.) and trimethylsilylacetamide (9.6 g.) in dry ethyl acetate (30 ml.), and the mixture was stirred for 50 minutes at -15° to -5° C. To the reaction mixture was added water (50 ml.). An insoluble material was filtered off and the filtrate was extracted twice with ethyl acetate. The extracts were washed twice with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and evaporated in vacuo. The residue was pulverized with diethyl ether and the powder was collected by filtration and dried to give 7-[2-t-butoxycarbonylmethoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (2.67 g.).

Provenance & Evidence