반응 #79291

반응 방정식

B(OiPr)3

3-bromo-o-xylene

tert-butyl lithium

HCl

pentane

→

2,3-dimethylphenylboronic acid

수율 185.2%

용매

THF

반응 조건

후처리

1. 1
   기타at −78° C.
2. 2
   온도the reaction mixture was raised to 20° C.
3. 3
   workup.STIRRINGstirred for 2 h
4. 4
   workup.STIRRINGthe acidic solution was stirred for 90 m
5. 5
   추출The reaction mixture was extracted
6. 6
   추출the organic solution was extracted
7. 7
   세척The aqueous solution was washed with Et2O (2×50 mL)
8. 8
   추출extracted
9. 9
   세척The organic solution was then washed with brine (100 mL)
10. 10
    건조dried over MgSO4
11. 11
    농축concentrated in vacuo

실험 절차

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.

출처