Phosphorus oxychloride → HCID 131712580, compound

Participants

Reaction Steps

The Vilsmeier reagent was prepared from dry dimethylformamide (0.4 g), phosphorus oxychloride (0.9 g) and dry ethyl acetate (1.6 ml) by the conventional method. Dry ethyl acetate (18 ml) was added thereto and then 2-ethoxyimino-2-(2-formamidothiazol-4-yl)acetic acid (syn isomer)(1.3 g) was added thereto at 0° C. The mixture was stirred for 30 minutes at the same temperature. The resulting mixture was added under -10° C. to a stirred solution of 7-amino-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (1.8 g) and trimethylsilylacetamide (4.6 g) in dry ethyl acetate (36 ml), and the mixture was stirred for 1 hour at the same temperature. To the reaction mixture was added water (30 ml). The ethyl acetate layer was separated and extracted with a saturated aqueous solution of sodium bicarbonate (pH 7.5). The aqueous layer was washed three times with ethyl acetate and adjusted to pH 2.0 with conc. hydrochloric acid after addition of ethyl acetate (100 ml). The ethyl acetate layer was separated, washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate, treated with an activated charcoal and concentrated to dryness to give 7-[2-ethoxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (2.56 g).

Provenance & Evidence