Boron tribromide → 2-Fluoro-5-hydroxybenzaldehyde

Temperature

0 °C

2-Fluoro-5-methoxy-benzaldehyde (4 g, 26 mmol) was dissolved in dry DCM (25 mL) under an argon atmosphere, cooled to 0° C. and slowly added boron tribromide (26 mL, 1.0 M in DCM, 26 mmol). On completion of the addition the reaction mixture was allowed to warm to RT and stirred for 16 h under an argon atmosphere. The reaction was carefully quenched with water (10 mL), added sat. NaHCO3 (30 mL), then shaken and the layers were separated. The aqueous phase was extracted with two more portions of DCM. The organic phases were combined, extracted with 2N NaOH (2×100 mL). The combined NaOH-phases were acidified with HCl (konc.) and extracted with DCM (4×150 mL). The organic phases were combined, dried (MgSO4), filtered, and concentrated in vacuo to afford the crude product. Purified by chromatography using EtOAc/petroleum ether (40-60)(v:v=1:5) as the eluent, affording the title compound as a white solid.

1. additionOn completion of the addition the reaction mixture
2. temperatureto warm to RT
3. customThe reaction was carefully quenched with water (10 mL)
4. additionadded sat. NaHCO3 (30 mL)
5. stirringshaken
6. customthe layers were separated
7. extractionThe aqueous phase was extracted with two more portions of DCM
8. extractionextracted with 2N NaOH (2×100 mL)
9. extractionextracted with DCM (4×150 mL)
10. dry with materialdried (MgSO4)
11. filtrationfiltered
12. concentrationconcentrated in vacuo
13. customto afford the crude product
14. customPurified by chromatography

ORD record

ord-5776025649f947aa8bdc7702642d95e3

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07977387B2