Phosphorus oxychloride → HCID 131712581, compound

Participants

Reaction Steps

The Vilsmeier reagent was prepared from dry dimethylformamide (0.5 g), phosphorus oxychloride (1.3 g) and dry ethyl acetate (2.0 ml) by the conventional method. Dry tetrahydrofuran (20 ml) was added thereto and then 2-(2-propynyl)oxyimino-2-(2-formamidothiazol-4-yl)acetic acid (syn isomer)(1.6 g) was added thereto at 0° C. The mixture was stirred for 30 minutes at the same temperature. The resulting mixture was added at -10° C. to a stirred solution of 7-amino-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (2.0 g) and trimethylsilylacetamide (5.1 g) in dry ethyl acetate (40 ml), and the mixture was stirred for 1 hour at -10° to -20° C. To the reaction mixture was added water (30 ml). The organic layer was separated and extracted with a saturated aqueous solution of sodium bicarbonate (30 ml). The aqueous layer was adjusted to pH 2.2 with conc. hydrochloric acid. Precipitates were collected by filtration, washed with water and dried to give colorless powder of 7-[2-(2-propynyl)oxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer)(2.40 g).

Provenance & Evidence