反应详情

2-Amino-5-bromo-4-fluoro-3-methoxy-6-methylbenzonitrile (I-45) (8.63 g, 33.30 mmol) was dissolved in methylene chloride (270 ml), and at −20° C., boron tribromide (1 M methylene chloride solution, 100 ml, 100.00 mmol) was gradually dropwise added. With gradually heating, this was stirred at room temperature for 15 hours. After the reaction, water with ice was added, followed by neutralization to pH of 7 with an aqueous saturated sodium hydrogencarbonate solution. Adding methylene chloride for fractionation was tried, but resulted in suspension, and therefore, this was dissolved in ethyl acetate, washed with saturated brine. The obtained organic layer was dried over anhydrous sodium sulfate, the solvent was evaporated away under reduced pressure. The resulting residue was recrystallized and purified with n-hexane/methylene chloride to obtain the entitled compound (7.86 g, 96%) as a pale brown solid.

1. temperatureWith gradually heating
2. additionwas added
3. customresulted in suspension
4. washwashed with saturated brine
5. dry with materialThe obtained organic layer was dried over anhydrous sodium sulfate
6. customthe solvent was evaporated away under reduced pressure
7. customThe resulting residue was recrystallized
8. custompurified with n-hexane/methylene chloride