反应详情

6N Hydrochloric acid (2 ml) was added to a solution of 7-(2-methoxyimino-3,3-diethoxy-4-bromobutyramido)-3-hydroxycepham-4-carboxylic acid (syn isomer, 500 mg) in methylene chloride (5 ml) under ice-cooling and stirred at room temperature for 70 minutes. The precipitates were collected by filtration, washed with a saturated aqueous solution of sodium chloride (5 ml) and methylene chloride (1 ml) successively, and dried over phosphorus pentachloride to give 7-(2-methoxyimino-3-oxo-4-bromobutyramido)-3-hydroxycepham-4-carboxylic acid (syn isomer, 517 mg), purity: 57.8%.

1. temperaturecooling
2. filtrationThe precipitates were collected by filtration
3. washwashed with a saturated aqueous solution of sodium chloride (5 ml) and methylene chloride (1 ml) successively
4. dry with materialdried over phosphorus pentachloride