Hexane → 5-Ethoxy-2-fluorophenol

Temperatur

-60 °C

To 4-ethoxy-1-fluorobenzene (1.0 g, 7.1 mmol) in THF (8.0 mL) was added freshly distilled N,N,N′,N″,N″-pentamethyldiethylenetriamine (0.8 mL) and 1.6 M n-butyllithium in hexane (5.13 ml, 8.2 mmol) at −78° C. After stirred at −60° C. for 1 h, trimethylborate (0.52 mL, 4.6 mmol) was introduced at −78° C. and the solution was warmed up to rt for 2 h. The reaction was quenched by acetic acid (1.5 ml) at 0° C. After 15 min, 30% hydrogen peroxide (1.2 ml) was introduced and the mixture was stirred from 0° C. to rt overnight. The mixture was extracted by EtOAc (3×30 mL). The combined organic layer was washed by brine, dried over MgSO4, and concentrated. The crude product was purified by column chromatography to give 1.0 g colorless oil of 74A. 1H NMR (400 MHz, CDCl3) δ ppm 1.39 (t, J=6.81 Hz, 3 H) 3.96 (q, J=7.03 Hz, 2H) 5.30 (d, J=2.20 Hz, 1H) 6.28-6.43 (m, 1H) 6.55 (dd, J=7.47, 3.08 Hz, 1H) 6.90-7.01 (m, 1H).

1. temperaturethe solution was warmed up to rt for 2 h
2. customThe reaction was quenched by acetic acid (1.5 ml) at 0° C
3. waitAfter 15 min
4. addition30% hydrogen peroxide (1.2 ml) was introduced
5. stirringthe mixture was stirred from 0° C. to rt overnight
6. extractionThe mixture was extracted by EtOAc (3×30 mL)
7. washThe combined organic layer was washed by brine
8. dry with materialdried over MgSO4
9. concentrationconcentrated
10. customThe crude product was purified by column chromatography

ORD-Eintrag

ord-24aa3e9901cf4bc793e5fc858972cb2d

Quelldatensatz

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07456195B2