反应详情

To a stirred slurry of 100 milligrams of 7-(5-(chloroacetamido)-5-carboxyvaleramido)-3-carbamoyloxymethyl-3-cephem-4-carboxylic acid in 10 milliliters of absolute methylene chloride was added 0.1 milliliters of pyridine and 0.15 milliliters of trimethylchlorosilane. The reaction mixture was stirred for two and one-half hours at room temperature. Then the reaction mixture was cooled to -15° C. and 0.2 milliliter of pyridine (in one lot), and 1.2 milliliter of 10 percent phosphorus pentachloride in absolute methylene chloride added dropwise, and the mixture stirred at -15° C. for two and one-half hours. Then 2 milliliters of absolute methanol were added, and the reaction mixture stirred for thirty minutes at -15° C. and for another thirty minutes at room temperature. Then 0.3 milliliter of 50 percent formic acid was added and the pH adjusted to 2 by adding triethylamine and stirring for forty-five minutes. The reaction mixture became cloudy. Then the pH was adjusted to 3.4, and the reaction mixture stirred for two hours in an ice bath and filtered. There was obtained 15 milligrams of 7-amino-3-carbamoyloxymethyl-3-cephem-4-carboxylic acid. It was identified by bioautogram and UV, which showed λ max. 262 nm (ε 5800).

1. temperatureThen the reaction mixture was cooled to -15° C.
2. stirringthe mixture stirred at -15° C. for two and one-half hours
3. stirringthe reaction mixture stirred for thirty minutes at -15° C. and for another thirty minutes at room temperature
4. stirringstirring for forty-five minutes
5. stirringthe reaction mixture stirred for two hours in an ice bath
6. filtrationfiltered