反应详情

70% Perchloric acid (0.54 ml) was added to a solution of 7-(2-methoxyimino-3,3-diethoxy-4-bromobutyramido)-3-cephem-4-carboxylic acid (syn isomer, 1 g) in methyl isobutyl ketone (4 ml) under ice-cooling, and stirred at the same temperature for 20 minutes. Water (4 ml) was added to the resultant mixture and stirred for 5 minutes. The precipiates were collected by filtration, washed with water and dried over phosphorus pentachloride in vacuo to give 7-(2-methoxyimino-3-oxo-4-bromobutyramido)-3-cephem-4-carboxylic acid (shyn isomer, 502 mg).

1. temperaturecooling
2. stirringstirred for 5 minutes
3. filtrationThe precipiates were collected by filtration
4. washwashed with water
5. dry with materialdried over phosphorus pentachloride in vacuo