反应详情

To a solution of 8.1 g. of ethyl α-methoxyimino-[2-(β,β,β-trichloroethoxycarbonylamino)thiazol-4-yl]acetate in 50 ml. of ethanol is added a solution of 11.2 g. of KOH in a mixture of 30 ml. of water and 150 ml. of ethanol. The whole mixture is stirred at room temperature for 1 hour, and then concentrated under reduced pressure. The residue is extracted with ethyl acetate. The water layer is made acidic with 10% aq. HCl and the separated solid is collected. Recrystallization of the solid from aq. methanol gives α-methoxyimino-[2-(β,β,β-trichloroethoxycarbonylamino)thiazol-4-yl]acetic acid. 4.1 g. Melting point: 162°-163° C.

1. concentrationconcentrated under reduced pressure
2. extractionThe residue is extracted with ethyl acetate
3. customthe separated solid is collected
4. customRecrystallization of the solid from aq. methanol