Hydrochloric Acid → 6-Fluoro-2,3-dihydroxybenzaldehyde

To a cold (−78° C.) solution of 6-fluoro-2,3-dimethoxy-benzaldehyde (4.50 g, 24.43 mmol) in anhydrous dichloromethane (30 mL) was added BBr3 (1M in DCM, 48.8 mL, 48.87 mmol) dropwise (duration 30 min). The reaction was warmed to room temperature and stirred for 4 h. Again cooled it to −78° C. and added 2N HCl (60 mL) to it dropwise. The reaction was stirred for overnight at room temperature and extracted with DCM. Combined organic layers were washed with water, sat. NaHCO3 solution, brine and dried over MgSO4. Filtration and removal of solvent provided 2.42 g (15.50 mmol, 64%) of the title compound as a yellow solid. This was used in the next step without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 10.22 (s, 1H), 7.04 (dd, J=8.6, 5.5 Hz, 1H), 6.61 (dd, J=10.4, 8.8 Hz, 1H); 19F NMR (376 MHz, DMSO-d6) δ ppm −131.69-−131.65 (m, 1F).

1. temperatureAgain cooled it to −78° C.
2. stirringThe reaction was stirred for overnight at room temperature
3. extractionextracted with DCM
4. washCombined organic layers were washed with water, sat. NaHCO3 solution, brine
5. dry with materialdried over MgSO4
6. filtrationFiltration and removal of solvent

ORD record

ord-e38acc20fef44d9abce264e85007789d

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08703742B2