反应详情

The solution of Vilsmeier reagent was prepared from dry N,N-dimethylformamido (0.475 g) and phosphoryl chloride (0.997 g) in dry tetrahydrofuran (1 ml) in a usual manner. A solution of 2-(2-cyclopenten-1-yl)oxyimino-2-(2-formamidothiazol-4-yl)acetic acid (syn isomer) (1.91 g) in dry tetrahydrofuran (12 ml) was added to the stirred suspension of the solution of Vilsmeier reagent at 0° to 5° C. and the mixture was stirred for 20 minutes. The resulting mixture was added to a solution of 7-amino-3-(4-carboxypyridin-2-yl)thiomethyl-3-cephem-4-carboxylic acid (1.84 g) and sodium bicarbonate (0.84 g) in a mixture of acetone (12 ml) and water (12 ml) at -3° to 0° C. and the mixture was stirred at the same temperature for 40 minutes. The reaction mixture was evaporated under reduced pressure. The residue was adjusted to pH 6.5 with 10% hydrochloric acid, washed with ethyl acetate, concentrated to a small volume and then adjusted to pH 2.9 with 10% hydrochloric acid. The precipitates were collected by filtration, washed with water and dried over phosphorus pentoxide to give 7-[2-(2-cyclopenten-1-yl)oxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(4-carboxypyridin-2-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (2.74 g).

1. stirringthe mixture was stirred at the same temperature for 40 minutes
2. customThe reaction mixture was evaporated under reduced pressure
3. washwashed with ethyl acetate
4. concentrationconcentrated to a small volume
5. filtrationThe precipitates were collected by filtration
6. washwashed with water
7. dry with materialdried over phosphorus pentoxide