Sodium Hydroxide → 2-(Trifluoromethoxy)phenylboronic Acid (contains varying amounts of Anhydride)

Temperature

-78 °C

To a stirred solution of 2 g (9.5 mmol) of 1-bromo-2-trifluoromethoxy benzene in 28 mL of tetrahydrofuran (THF) at −78° C., was carefully added 5.9 mL of a 1.7 M solution of t-butyl lithium in hexanes (9.5 mmol). This reaction mixture was stirred at −78° C. for 45 min. To this reaction mixture at −78° C. was added 2.58 mL (11.1 mmol) of tri-isopropyl borate, followed by slow warming of the mixture to room temperature (RT) over a period of 16 h. The reaction mixture was diluted with water and made basic with 2N NaOH solution. The mixture was then washed with EtOAc. The aqueous fraction was acidified with 2N HCl solution and stirred for 1 h at RT. The reaction mixture was extracted with EtOAc and the organic fractions were washed with water and saturated NaCl solution (brine), dried over Na2SO4 and filtered. The filtrate was concentrated to give the title compound as a white solid. 1H NMR (CDCl3) (δ, ppm): 7.96 (dd, J=7.2, 1.6 Hz, 1 H), 7.53 (ddd, J=9.1, 7.3, 1.8 Hz, 1 H), 7.38 (td, J=7.3, 0.7 Hz, 1 H), 7.28 (d, J=8.2 Hz, 1 H), 5.25 (br s, 2H). MS (M+H): 206.9.

1. customat −78° C.
2. temperatureby slow warming of the mixture to room temperature (RT) over a period of 16 h
3. washThe mixture was then washed with EtOAc
4. stirringstirred for 1 h at RT
5. extractionThe reaction mixture was extracted with EtOAc
6. washthe organic fractions were washed with water and saturated NaCl solution (brine)
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationThe filtrate was concentrated

ORD record

ord-ff8774baf8a840e9bb1b589c83eaf6a2

Source dataset

uspto-grants-2008_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07459475B2