Phosphorus oxychloride → HCID 131712240, compound

Participants

Reaction Steps

A mixture of 2-methoxyimino-2-(5-amino-1,2,4-thiadiazol-3-yl)acetic acid (syn isomer) (1.21 g) and phosphorus oxychloride (3.67 g) in methylene chloride (30 ml) was stirred for two hours at ambient temperature, cooled to 0° C. and thereto was added N,N-dimethylformamide (2.4 ml), followed by stirring for an additional 45 minutes at 0° C. A mixture of 7-amino-2-methyl-3-cephem-4-carboxylic acid (3.0 g) and trimethylsilylacetamide (10 g) in methylene chloride (50 ml) was warmed to make a clear solution. The solution was cooled to -15° C. and added to the above obtained solution, followed by stirring for 30 minutes at 0° C. The reaction mixture was poured into a cold aqueous solution of sodium bicarbonate. The aqueous layer was separated and thereto was added ethyl acetate. The resulting mixture was adjusted to pH 2 with 10% hydrochloric acid and the ethyl acetate layer was separated, dried over anhydrous magnesium sulfate and then evaporated. The residue was triturated with diethyl ether to give a crude product of the title compound (2.2 g). The crude material was dissolved in an aqueous solution of sodium bicarbonate, adjusted to pH 2 with 10% hydrochloric acid. The precipitates were collected by filtration, washed with ice-water and dried to give the title compound (1.6 g), mp. 175° to 180° C. (dec.).

Provenance & Evidence