Hydrochloric Acid → 2-(Trifluoromethyl)benzeneboronic acid

Temperature

10 °C

To a solution of 58.8 g (0.261 mol) of 1-bromo-2-(trifluoromethyl)benzene in 250 mL of THF under Ar was added 110 mL (0.275 mol) of 2.5M n-butyllithium in hexane over 35 minutes, keeping the temperature between 0-5° C. The reaction mixture was allowed to warm to 10° C. Triisopropylborate (95 mL, 0.313 mol) was added, keeping the temperature below 35° C. After 1 hour, the reaction mixture was cooled, 1N HCl (425 mL) was added, and the mixture was stirred overnight. The mixture was extracted with 100 mL of ether three times, and the combined organic extracts were extracted with 100 mL of 1N NaOH three times. The aqueous extracts were acidified to pH 1 with 6N HCl, and then extracted with 100 mL ether three times. The combined ether extracts were dried over MgSO4, and the solvents evaporated in vacuo to give 46.1 g (93%) of the desired compound as a light yellow oil. 1H NMR (CDCl3) δ: 7.77 (d, 1H); 7.72 (d, 1H); 7.56 (m, 2H); 4.87 (br s, 2H).

1. custombetween 0-5° C
2. customthe temperature below 35° C
3. temperaturethe reaction mixture was cooled
4. extractionThe mixture was extracted with 100 mL of ether three times
5. extractionthe combined organic extracts were extracted with 100 mL of 1N NaOH three times
6. extractionextracted with 100 mL ether three times
7. dry with materialThe combined ether extracts were dried over MgSO4
8. customthe solvents evaporated in vacuo

ORD record

ord-751da6e3a67d449f97de45f661a5d0ed

Source dataset

uspto-grants-2005_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06962935B2