Trimethyl borate → 5-Ethyl-2-fluorophenol

To a solution of 1-ethyl-4-fluorobenzene (7.2 g, 58 mmol) in THF (30 mL) and N,N,N′,N″,N″-pentamethyldiethylenetriamine (3.0 mL) was added n-BuLi (1.6M in hexane, 42 mL) at −78° C. After 1 h stirring, trimethyl borate (13 mL) was added. The mixture was stirred from −78° C. to rt overnight. It was quenched by acetic acid (5.0 mL) and hydrogen peroxide solution (30% in water) at 0° C. The mixture was stirred for 2 h before extracted with EtOAc. The organic extracts were washed with brine, dried over MgSO4 and concentrate to give 118A (7.6 g, 94% yield) as an oil. 1H NMR (400 MHz, CDCl3) δ ppm 1.19 (t, J=7.69 Hz, 3H) 2.56 (q, J=7.62 Hz, 2H) 6.60-6.71 (m, 1H) 6.83 (dd, J=8.79, 2.20 Hz, 1H) 6.95 (dd, J=10.55, 8.35 Hz, 1H).

1. stirringThe mixture was stirred from −78° C. to rt overnight
2. customIt was quenched by acetic acid (5.0 mL) and hydrogen peroxide solution (30% in water) at 0° C
3. stirringThe mixture was stirred for 2 h
4. extractionbefore extracted with EtOAc
5. washThe organic extracts were washed with brine
6. dry with materialdried over MgSO4
7. concentrationconcentrate

ORD record

ord-95c4824d677f4a9f996a87d3e1c94e40

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07622585B2