Hydrochloric Acid → 7-[2-(2-Cyclopenten-1-yl)oxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-(tetrazolo[1,5-b] pyridazin-6-yl)thiomethyl-3-cephem-4-carboxylic acid

Participants

Reaction Steps

A suspension of 7-[2-(2-cyclopenten-1-yl)oxyimino-2-(2-formamidothiazol-4-yl)acetamido]-3-(tetrazolo[1,5-b]pyridazin-6-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (1.7 g) in methanol (12.0 ml) and conc.hydrochloric acid (0.56 g) was stirred and then thereto was added tetrahydrofuran (12.0 ml) to give a homogenous solution, which was stirred for 2 hours and 50 minutes at room temperature. To the reaction mixture were added water and sodium bicarbonate so that the pH was adjusted to 5.0. After the concentration of the mixture, to the concentrate were added ethyl acetate, water and sodium bicarbonate so that the pH was adjusted to 7.5. The aqueous layer was separated, washed with ethyl acetate (×2), concentrated and adjusted to pH 3.0 with 10% hydrochloric acid. The precipitates were collected by filtration, washed with water, dried over phosphorus pentoxide under reduced pressure to give 7-[2-(2-cyclopenten-1-yl)oxyimino-2-(2-aminothiazol-4-yl)acetamido]-3-(tetrazolo[1,5-b] pyridazin-6-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (1.00 g). mp. 178° to 180° C. (dec.).

Provenance & Evidence