Hydrochloric Acid → 2-Methoxy-3-(trifluoromethyl)phenylboronic acid

To a solution of 1-methoxy-2-(trifluoromethyl)benzene (6.30 g, 35.8 mmol) in THF (150 mL) was added n-BuLi (21.0 ml, 2.50 M hexane solution, 53.7 mmol), and the mixture was stirred at room temperature for 1 hr. The solution was cooled to −78° C., tris(1-methylethyl)borate (8.08 g, 43.0 mmol) was added, and the mixture was stirred at −78° C. for 0.5 hr. The reaction solution was allowed to cool to room temperature and stirred for 16 hr. The mixture was acidified with 1M hydrochloric acid and extracted with ethyl acetate (300 mL). The extract was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to give a mixture (6.52 g, yield 83%) of [2-methoxy-3-(trifluoromethyl)phenyl]boronic acid and [3-methoxy-2-(trifluoromethyl)phenyl]boronic acid.

1. temperatureThe solution was cooled to −78° C.
2. stirringthe mixture was stirred at −78° C. for 0.5 hr
3. temperatureto cool to room temperature
4. stirringstirred for 16 hr
5. extractionextracted with ethyl acetate (300 mL)
6. dry with materialThe extract was dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure

ORD record

ord-694e63a1b94743f18cb1119bbb1180c5

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08338622B2