Hydrochloric Acid → (3-Ethoxy-4-methoxyphenyl)boronic acid

Temperature

-78 °C

A mixture of 4-Bromo-2-ethoxy-1-methoxybenzene (4.00 g, 17.3 mmol) in THF (75 mL) was cooled to −78° C.; during cooling, a precicipitate formed. t-BuLi (22.4 mL, 1.7 M in pentane, 38.1 mmol) was added dropwise, while maintaining the temperature at −78° C. The mixture was stirred at −78° C. for 1 hour following completion of the addition. B(Oi-Pr)3 (9.76 g, 51.9 mmol) was added. The mixture was allowed to gradually warm to room temperature, and then stirred under nitrogen for 16 hours. 3N HCl (20 mL) was added, and the mixture stirred for 10 minutes. The mixture was poured into water (100 mL) and extracted with diethyl ether (3×75 mL), and the combined ethereal layers were washed with water (3×75 mL), dried (MgSO4) and evaporated, providing 3.15 g of the product in 93% yield: 1H NMR (DMSO-d6) δ 1.32 (t, J=7.0 Hz, 3H), 3.75 (s, 3H), 3.99 (q, J=7.0 Hz, 2H), 6.90 (d, J=8.3 Hz, 1H), 7.35-7.37 (m, 2H).

1. temperatureduring cooling
2. customa precicipitate formed
3. temperaturewhile maintaining the temperature at −78° C
4. additioncompletion of the addition
5. temperatureto gradually warm to room temperature
6. stirringstirred under nitrogen for 16 hours
7. stirringthe mixture stirred for 10 minutes
8. extractionextracted with diethyl ether (3×75 mL)
9. washthe combined ethereal layers were washed with water (3×75 mL)
10. dry with materialdried (MgSO4)
11. customevaporated

ORD record

ord-68573e4d0b664df698720a25c393cd8b

Source dataset

uspto-grants-2013_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08481568B2