Diisopropylamine → 2-(4-Chloro-2-fluoro-3-(1-fluoroethyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Temperatur

-78 °C

A 2.5M solution of n-butyllithium (13 mL, 33 mmol) was added to a stirred solution of diisopropylamine (5.0 mL, 35 mmol) in THF (50 mL) at −78° C. The resulting colorless solution was stirred at −78° C. for 20 min, warmed to 0° C. for 20 min, and then cooled back to −78° C. for 20 min. A solution of 1-chloro-3-fluoro-2-(1-fluoroethyl)benzene (4.8 g, 27 mmol, 1.0 equiv) in THF (20 mL) at −78° C. was transferred to the base solution via cannula. The resulting dark brown solution was stirred at −78° C. for 2 h. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (8.3 mL, 41 mmol, 1.5 equiv) was added and the brown solution was slowly warmed to 23° C. over 20 h. The reaction mixture was diluted with 0.1M hydrochloric acid (300 mL) and extracted with dichloromethane thrice. The combined organic extracts were dried, filtered and concentrated by rotary evaporation to afford the title compound as a brown oil that solidified into a semi-solid upon standing (7.7 g, 94% yield). 1H NMR (300 MHz, CDCl3) δ 7.62 (m, 1H), 7.17 (m, 1H), 6.13 (dq, 1H, J=6, 46 Hz), 1.75 (ddd, 3H, J=1, 7, 23 Hz), 1.36 (s, 12H).

1. temperaturewarmed to 0° C. for 20 min
2. temperaturecooled back to −78° C. for 20 min
3. customat −78° C.
4. stirringThe resulting dark brown solution was stirred at −78° C. for 2 h
5. temperaturethe brown solution was slowly warmed to 23° C. over 20 h
6. extractionextracted with dichloromethane thrice
7. customThe combined organic extracts were dried
8. filtrationfiltered
9. concentrationconcentrated by rotary evaporation

ORD-Eintrag

ord-69b5388fc2d445bd9bd32e0b333f98f9

Quelldatensatz

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07786044B2