Sodium Chloride → HCID 131712612, compound

Participants

Reaction Conditions

Reaction Steps

To dimethylformamide (0.4 g) was added dropwise phosphorus oxychloride (0.84 g) under stirring and ice-cooling, and the mixture was stirred for 30 minutes at 40° C. and then suspended in ethyl acetate (10 ml). To the suspension was added 2-(2-propynyloxyimino)-2-(2-formylaminothiazol-4-yl)acetic acid (syn isomer) (1.27 g) under stirring and ice-cooling and then stirred for 30 minutes under ice-cooling. Thus obtained solution was added to a solution, which was prepared by stirring a mixture of 2-methyl-7-amino-3-cephem-4-carboxylic acid (1.44 g) and trimethylsilylacetamide (5.2 g) in tetrahydrofuran (40 ml), under cooling to -25° C. The mixture was stirred for 1 hour at -20° C. to -10° C., and a saturated aqueous solution of sodium chloride (100 ml) was added thereto. Thus obtained mixture was adjusted to pH 7.5 with 20% aqueous solution of sodium carbonate, and the aqueous layer was separated. To the aqueous layer was added ethyl acetate, and adjusted to pH 2 with 10% hydrochloric acid, and then extracted with ethyl acetate. The ethyl acetate layer was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and then evaporated. The residue was pulverized in diethyl ether, collected by filtration and then dried to give 2-methyl-7-[2-(2-propynyloxyimino)-2-(2-formylaminothiazol-4-yl)acetamido]-3-cephem-4-carboxylic acid (syn isomer) (2.2 g).

Provenance & Evidence