反应详情

To a solution of 5 g of 5-fluoro-2-methylaniline in 30 mL of pyridine was added 4.6 mL of acetic anhydride, and stirred at room temperature for 4 hours. After distilling off the pyridine under reduced pressure, the residue was dissolved in 250 mL of ethyl acetate, and washed successively with water, 1N hydrochloric acid, water, saturated aqueous sodium hydrogen carbonate and saturated brine. The solution was dried over anhydrous magnesium sulfate, allowed to pass though a silica gel pad, and then the solvent was evaporated. The residue was recrystallized from ethyl acetate-diethyl ether, to afford 5.34 g of the title compound as white needle crystals. The mother liquor was further concentrated, and triturated with diethyl ether, to afford 907 mg of the title compound as purple needle crystals.

1. distillationAfter distilling off the pyridine under reduced pressure
2. dissolutionthe residue was dissolved in 250 mL of ethyl acetate
3. washwashed successively with water, 1N hydrochloric acid, water, saturated aqueous sodium hydrogen carbonate and saturated brine
4. dry with materialThe solution was dried over anhydrous magnesium sulfate
5. customthe solvent was evaporated
6. customThe residue was recrystallized from ethyl acetate-diethyl ether