Hydrochloric Acid → 2-Methoxy-5-(trifluoromethyl)phenylboronic acid

Temperature

-30 °C

A solution of 4-trifluoromethylanisole (8 g; 45 mmol) in dry THF (80 ml) at −30° C. under N2 was added a solution of 2.5 M n-BuLi in hexane (20 ml; 50 mmol). The reaction mixture was stirred for 1 h at −30° C., then cooled to −70° C. and added B(Oi-Pr)3 (14.1 ml; 64 mmol). The reaction mixture was allowed to slowly warm up to rt. over night. The reaction mixture was added 2 M HCl (40 ml) and THF was removed by evaporation. The aqueous remanense was extracted with Et2O (4×20 ml) and the combined organic fractions were extracted with 1 M NaOH (5×17 ml). The combined aqueous fractions were neutralized by 10 M HCl. The precipitate formed was isolated by filtration and washed with 1 M HCl to give 8.1 g (81%) product.

1. temperaturecooled to −70° C.
2. temperatureto slowly warm up to rt
3. waitover night
4. customwas removed by evaporation
5. extractionThe aqueous remanense was extracted with Et2O (4×20 ml)
6. extractionthe combined organic fractions were extracted with 1 M NaOH (5×17 ml)
7. customThe precipitate formed
8. customwas isolated by filtration
9. washwashed with 1 M HCl

ORD record

ord-67183aac018141ab8ad6c4784413459a

Source dataset

uspto-grants-2007_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07235548B2