Tetrafluoroboric acid → 1-tert-Butyl-3-fluorobenzene

To a vigorously stirred solution of tetrafluoroboric acid (73.26 mL; 0.4 mol; 48% wt % solution in water) in a large beaker at room temperature was slowly added 3-tert-butylaniline (15.0 g; 0.10 mmol). The resulting mixture was stirred at room temperature for 30 minutes, cooled to 0° C. and then a solution of sodium nitrite (11.09 g; 0.16 mol) in water (30 mL) was added. After addition was complete reaction mixture was stirred at 0° C. for 30 minutes, warmed to room temperature and further stirred for 20 minutes. The resulting beige slushy material was filtered, washed with tetrafluoroboric acid (20 mL) and ether (3×20 mL) to yield an off-white solid (13.54 g). The latter was dissolved in dichloromethane (300 mL) and heated at reflux for 2 hours until the solid was dissolved and no more gas (HF) evolution was observed. The reaction mixture was cooled to room temperature and concentrated under reduced pressure to yield a dark oil that was purified by column chromatography eluting with ethyl acetate/hexanes (0 to 5% v/v gradient elution over 1 L) to yield the title compound as a pale yellow liquid (11.80 g).

1. customat room temperature
2. temperaturecooled to 0° C.
3. additionAfter addition
4. stirringwas stirred at 0° C. for 30 minutes
5. temperaturewarmed to room temperature
6. stirringfurther stirred for 20 minutes
7. filtrationThe resulting beige slushy material was filtered
8. washwashed with tetrafluoroboric acid (20 mL) and ether (3×20 mL)

ORD record

ord-aa15968c1f6d49e8ad2ee2e615e09a79

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08178699B2