Phosphorus oxychloride → 3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-7-[2-(2-propanesulfonylamino-1,3-thiazol-4-yl)glyoxylamido]-3-cephem-4-carboxylic acid

Participants

Reaction Steps

To dimethylformamide (1.59 g.) was dropwise added phosphorus oxychloride (4.16 g.) under stirring and ice-cooling, and the mixture was stirred for 30 minutes at 40° C. To the mixture was added ethyl acetate (20 ml.) with stirring, and the mixture was cooled to -20° to -10° C. with stirring. To the mixture was dropwise added a mixture of 2-(2-propanesulfonylamino-1,3-thiazol-4-yl)glyoxylic acid, which can be represented as 2-(2-propanesulfonylimino-2,3-dihydro-1,3-thiazol-4-yl)glyoxylic acid, (6.0 g.), ethyl acetate (60 ml.) and dimethylformamide (4 ml.) over 10 minutes at -20° to -10° C. with stirring, and then the mixture was stirred for 40 minutes at the same temperature. Thus obtained mixture was dropwise added to the solution prepared in the similar manner as in Example 1 from 3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-7-amino-3-cephem-4carboxylic acid (7.8 g.), bis(trimethylsilyl)acetamide (22.9 ml.) and ethyl acetate (156 ml.), at -40° C. over 5 minutes with stirring. The mixture was stirred for 30 minutes at the same temperature and further stirred for 1 hour at -5° to 0° C. After the reaction, the reaction mixture was poured into 5% sodium bicarbonate aqueous solution (150 ml.), and the aqueous layer was separated. The remaining ethyl acetate layer was further extracted with 5% sodium bicarbonate aqueous solution, and the extract was combined with the separated aqueous layer. The aqueous solution was washed with ethyl acetate, and ethyl acetate was added thereto. The mixture was adjusted to pH 2 with 10% hydrochloric acid and filtered, and then the ethyl acetate layer was separated from the filtrate. The remaining aqueous layer was further extracted with ethyl acetate, and the extract was combined with the separated ethyl acetate layer. The ethyl acetate layer was washed with water, dried and then the solvent was distilled off. The residue was pulverized in diethyl ether, collected by filtration and dried to give 3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-7-[2-(2-propanesulfonylamino-1,3-thiazol-4-yl)glyoxylamido]-3-cephem-4-carboxylic acid, which can be represented as 3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-7-[2-(2-propanesulfonylimino-2,3-dihydro-1,3-thiazol4-yl)glyoxylamido]-3-cephem-4-carboxylic acid, (11.0 g.), m.p. 150° C.(dec.).

Provenance & Evidence