Phosphorus oxychloride → HCID 131712610, compound

Participants

Reaction Steps

The Vilsmeier reagent was prepared from dry dimethylformamide (2.6 g.), phosphorus oxychloride (5.4 g.) and dry ethyl acetate (10.4 ml) by the conventional method. Dry ethyl acetate (100 ml) was added thereto and then 2-cyclopentyloxyimino-2-[2-(2,2,2-trifluoroacetamido)thiazol-4-yl]acetic acid (syn isomer) (10.4 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 (9.6 g) and trimethylsilylacetamide (24.8 g) in dry ethyl acetate (192 ml), and the mixture was stirred for 30 minutes at the same temperature. To the reaction mixture was added water. The ethyl acetate layer was separated and extracted with aqueous solution of sodium bicarbonate (pH 7.5). The aqueous layer was washed twice with ethyl acetate and adjusted to pH 2.0 with 10% hydrochloric acid after addition of ethyl acetate and tetrahydrofuran. The organic layer was separated, washed with water, dried over magnesium sulfate, treated with an activated charcoal and concentrated to dryness. The residue was pulverized with diethyl ether and the powder was collected by filtration and washed with diethyl ether to give 7-[2-cyclopentyloxyimino-2-{2-(2,2,2-trifluoroacetamido)thiazol-4-yl}acetamido]-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (18.18 g).

Provenance & Evidence