反应详情

温度

50 °C

A mixture of acetic anhydride (15.9 g.) and formic acid (7.15 g.) was stirred at 50° C. for an hour. After cooling, ethyl 2-(2-aminothiazol-4-yl)-2-(2-bromoethoxyimino)acetate (syn isomer, 25 g.) was added to the solution and stirred at room temperature for an hour. The resultant solution was poured into water and extracted with ethyl acetate twice. The extracts were washed with a saturated aqueous solution of sodium chloride, a saturated aqueous solution of sodium bicarbonate (three times) and a saturated aqueous solution of sodium chloride in turn, and dried over magnesium sulfate. After concentrating the solution in vacuo, the oily residue was triturated with a mixture of diisopropyl ether and diethyl ether. The precipitates were collected by filtration to give ethyl 2-(2-formamidothiazol-4-yl)-2-(2-bromoethoxyimino)acetate (syn isomer, 16.75 g.), mp. 95° to 98° C.

1. temperatureAfter cooling
2. stirringstirred at room temperature for an hour
3. extractionextracted with ethyl acetate twice
4. washThe extracts were washed with a saturated aqueous solution of sodium chloride
5. dry with materiala saturated aqueous solution of sodium bicarbonate (three times) and a saturated aqueous solution of sodium chloride in turn, and dried over magnesium sulfate
6. concentrationAfter concentrating the solution in vacuo
7. customthe oily residue was triturated with a mixture of diisopropyl ether and diethyl ether
8. filtrationThe precipitates were collected by filtration