Phosphorus oxychloride → HCID 131712600, compound

Participants

Reaction Steps

2-Ethoxyimino-2-(2-formamidothiazol-4-yl)acetic acid (syn isomer) (3.0 g.) and dry ethyl acetate (40 ml.) were added at 0° to 5° C. with stirring to a suspension of Vilsmeier reagent prepared from dry dimethylformamide (1.0 g.) and phosphorus oxychloride (2.1 g.) in dry ethyl acetate (4.0 ml.) by conventional method, and the resulting mixture was stirred for 30 minutes at the same temperature. The solution was added at -10° C. with stirring to a solution of 7-amino-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (3.7 g.), trimethylsilylacetamide (10.3 g.) and bis-(trimethylsilyl)acetamide (6.8 g.) in dry ethyl acetate (80 ml.), and the mixture was stirred for 1.5 hours at the same temperature. After addition of water (50 ml.) to the reaction mixture, an insoluble material was filtered off, the ethyl acetate layer in the filtrate was separated and extracted with an aqueous solution of sodium bicarbonate (50 ml.). The aqueuous extract was washed with ethyl acetate and acidified to pH 2.0 with conc. hydrochloric acid. Precipitates were collected by filtration, washed with water and dried to give powder of 7-[2-ethoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (2.3 g.).

Provenance & Evidence