Boron tribromide → 3-Fluoro-4-hydroxybenzaldehyde

Temperature

-78 °C

To a 25 mL RB flask fitted with magnetic stirrer was charged with 20 mL of dichloromethane. To the stirred solvent was added 3-fluoro-4-methoxybenzaldehyde (2 g, 12.97 mmol). The reaction mixture was cooled to −78° C. and boron tribromide (51 mL) was added drop wise, stirred for 2 h at the same temperature and stirred at RT about 16 h. The reaction mixture was quenched with NaHCO3 solution at 0° C. by slow addition. The reaction mixture was concentrated to distill off the solvent; ethyl acetate (20 mL) was added. The organic layer was washed with saturated NaHCO3 solution (20 mL), followed by brine solution (20 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as white solid (1.0 g, yield: 54.94%). 1H NMR (300 MHz, CDCl3): δ 9.77 (s, 1H), 7.54-7.59 (m, 1H), 7.08-7.12 (t, 1H), 6.40 (s, 1H).

1. customTo a 25 mL RB flask fitted with magnetic stirrer
2. stirringstirred at RT about 16 h
3. customThe reaction mixture was quenched with NaHCO3 solution at 0° C. by slow addition
4. concentrationThe reaction mixture was concentrated
5. distillationto distill off the solvent
6. additionethyl acetate (20 mL) was added
7. washThe organic layer was washed with saturated NaHCO3 solution (20 mL)
8. dry with materialThe organic layer was dried over anhydrous Na2SO4
9. customthe solvent was removed under reduced pressure

ORD record

ord-138769fcfe904d82b35ebfb32fe6dc28

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09278915B2