反应详情

70% Perchloric acid (1.09 ml.) was added to a solution of 7-(2-methoxyimino-3,3-ethylenedioxybutyramido)-3-cephem-4-carboxylic acid (syn isomer, 10.9 g.) in acetone (270 ml.) and stirred at room temperature for 3 hours. Water (150 ml.) was added to the resultant solution and acetone was removed in vacuo. Ethyl acetate (300 ml.) was added to the residue and the ethyl acetate layer was separated. The aqueous layer was extracted with ethyl acetate (400 ml.) and then the ethyl acetate extract was combined with ethyl acetate layer. The organic solution was washed with a sodium chloride saturated aqueous solution, allowed to stand in refrigerator overnight and dried over magnesium sulfate. The solution was concentrated in vacuo and the residue was pulverized with diisopropyl ether to give 7-(2-methoxyimino-3-oxobutyramido)-3-cephem-4-carboxylic acid (syn isomer, 5.75 g.).

1. customwas removed in vacuo
2. additionEthyl acetate (300 ml.) was added to the residue
3. customthe ethyl acetate layer was separated
4. extractionThe aqueous layer was extracted with ethyl acetate (400 ml.)
5. extractionthe ethyl acetate extract
6. washThe organic solution was washed with a sodium chloride saturated aqueous solution
7. customto stand in refrigerator overnight
8. dry with materialdried over magnesium sulfate
9. concentrationThe solution was concentrated in vacuo