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

Temperature

-60 °C

To a solution of 6-fluoro-2,3-dimethoxy-benzaldehyde (18.0 g, 97.74 mmol) in anhydrous dichloromethane (100 mL) under nitrogen at −60° C. was added dropwise BBr3.OEt2 (195 mL, 195.48 mmol) over 30 min and the solution was allowed to warm up to r.t and stirred for 4 h. The reaction mixture was cooled to −60° C. and 2N HCl (250 mL) was carefully added drop wise. The mixture was stirred at r.t overnight. The two layers were separated and the aqueous layer extracted with DCM. The combined organic layers were washed with water, sat. NaHCO3 solution, water and brine and dried over MgSO4. The solvent was removed in vacuo to provide the title compound which was used in the next step without further purification. Yield 11.15 g (74%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 11.53 (s, 1H), 10.23 (s, 1H), 7.11 (dd, J=8.8, 5.3 Hz, 1H), 6.57 (t, J=9.6 Hz, 1H), 5.48 (s, 1H). 19F NMR (376 MHz, CHLOROFORM-d): −132 ppm.

1. temperatureto warm up
2. stirringThe mixture was stirred at r.t overnight
3. customThe two layers were separated
4. extractionthe aqueous layer extracted with DCM
5. washThe combined organic layers were washed with water, sat. NaHCO3 solution, water and brine
6. dry with materialdried over MgSO4
7. customThe solvent was removed in vacuo

ORD record

ord-48adcc12381a414aa9d56da37f2d3eb8

Source dataset

uspto-grants-2014_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08703742B2