Hydrochloric Acid → 2,3-Dimethylphenylboronic acid

Temperatur

-78 °C

To a solution of 3-bromo-o-xylene (500 mg, 2.7 mmol) in THF (15 mL) at −78° C. under N2 was slowly added 1.7 M tert-butyl lithium in pentane (1.77 mL, 3.0 mmol). This was stirred at −78° C. for 30 m. To the reaction mixture was added B(OiPr)3 (2.05 g, 11 mmol), and the reaction mixture was raised to 20° C. and stirred for 2 h. 3 N HCl (10 mL) was added to the reaction mixture and the acidic solution was stirred for 90 m. The reaction mixture was extracted using EtOAc (4×50 mL), and the organic solution was extracted using a 1 N solution of NaOH (100 mL). The aqueous solution was washed with Et2O (2×50 mL), acidified to pH 1 using concentrated HCl, and then extracted using EtOAc (4×50 mL). The organic solution was then washed with brine (100 mL), dried over MgSO4 and concentrated in vacuo to afford 2,3-dimethylphenylboronic acid compound (750 mg, 45%) as a white solid.

1. customat −78° C.
2. temperaturethe reaction mixture was raised to 20° C.
3. stirringstirred for 2 h
4. stirringthe acidic solution was stirred for 90 m
5. extractionThe reaction mixture was extracted
6. extractionthe organic solution was extracted
7. washThe aqueous solution was washed with Et2O (2×50 mL)
8. extractionextracted
9. washThe organic solution was then washed with brine (100 mL)
10. dry with materialdried over MgSO4
11. concentrationconcentrated in vacuo

ORD-Eintrag

ord-4ebf32fe053649d997731f91acab588c

Quelldatensatz

uspto-grants-2004_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06713471B1