反应详情

温度

-20 °C

In 127 ml of methylene chloride was suspended 1.27 g of ethyl 7-bromo-1-cyclopropyl-6-fluoro-8-hydroxymethyl-1,4-dihydro-4-oxoquinoline-3-carboxylate, and 1.33 g of diethylaminosulfur trifluoride was dropwise added to the suspension at -40° C., after which the resulting mixture was stirred at -20° C. for one hour and then at 0° C. for three hours. The reaction mixture was added to 120 ml of ice water and the pH was adjusted to 8 with a saturated aqueous sodium hydrogencarbonate solution. Thereafter, the organic layer formed was separated, washed with a saturated saline solution and then dried over anhydrous magnesium sulfate. The solvent was then removed by distillation under reduced pressure. The residue thus obtained was purified by a column chromatography (eluent: chloroform:ethanol=100:1), to obtain 1.05 g of colorless, crystalline ethyl 7-bromo-1-cyclopropyl-6-fluoro-8-fluoromethyl-1,4-dihydro-4-oxoquinoline-3-carboxylate.

1. additionwas dropwise added to the suspension at -40° C.
2. waitat 0° C. for three hours
3. customThereafter, the organic layer formed
4. customwas separated
5. washwashed with a saturated saline solution
6. dry with materialdried over anhydrous magnesium sulfate
7. customThe solvent was then removed by distillation under reduced pressure
8. customThe residue thus obtained
9. customwas purified by a column chromatography (eluent: chloroform:ethanol=100:1)