Triisopropyl borate → 4-Chloro-3-(5-(trifluoromethyl)pyridin-2-yloxy)phenylboronic acid

Temperature

-40 °C

To a solution of 2-(5-bromo-2-chlorophenoxy)-5-(trifluoromethyl)pyridine (2.6 g, 7.3 mmol) and triisopropylborate (2.0 mL, 8.76 mmol) in toluene (15 mL) and THF (7 mL) under a N2 atmosphere was added n-BuLi (6.8 mL, 10.95 mmol) while maintaining the reaction at −70° C. The reaction was stirred for 1 h at −40° C. Gradually the temperature was increased to −20° C. and then 0° C. The reaction was quenched with 2N HCl and allowed to warm to RT. The reaction mixture was concentrated and extracted with EtOAc. The organic extract was dried over Na2SO4 and concentrated under reduced pressure to give the title compound (2.8 g). 1H NMR (500 MHz, DMSO-d6): δ 8.56 (s, 1H), 8.29 (m, 3H), 7.94 (s, 1H), 7.81 (d, J=7.9 Hz, 1H), 7.36 (d, J=8.05 Hz, 2H); m/z (316.4, M− H−).

1. temperaturewhile maintaining
2. customthe reaction at −70° C
3. temperatureGradually the temperature was increased to −20° C.
4. custom0° C
5. customThe reaction was quenched with 2N HCl
6. temperatureto warm to RT
7. concentrationThe reaction mixture was concentrated
8. extractionextracted with EtOAc
9. extractionThe organic extract
10. dry with materialwas dried over Na2SO4
11. concentrationconcentrated under reduced pressure

ORD record

ord-2387065bed744819acdf172bff9cdf73

Source dataset

uspto-grants-2011_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08044052B2