3-Bromo-5-(trifluoromethyl)benzoic acid → [3-Bromo-5-(trifluoromethyl)phenyl]methanol

To a solution of 3-bromo-5-(trifluoromethyl)benzoic acid (2.13 gm, 7.92 mmol) in anhydrous THF under nitrogen was added borane dimethylsulfide complex (15.83 mmol, 7.91 mL) and the mixture was stirred at room temperature for 16 hours. A further aliquot of borane dimethylsulfide complex (15.83 mmol, 7.91 mL) was then added and stirring was continued at room temperature for a further 4 hours. LC-MS indicated complete consumption of starting material. Methanol was added cautiously until effervescence ceased then 2N hydrochloric acid (20 mL) was added. The mixture was stirred at room temperature for 20 hours then concentrated to dryness under reduced pressure. The residue was extracted with diethyl ether and the solution washed with water. The organic layer was dried with anhydrous sodium sulfate and the solvent removed under vacuum. The residue was dissolved in a mixture of dichloromethane and methanol, silica gel was added and the solvent removed under vacuum. The solid was placed on a column of silica gel (50 gm) and eluted with hexane-ethyl acetate (85:15) to give the title compound as a yellow oil which crystallized on standing (1.16 gm, 57%).

1. additionA further aliquot of borane dimethylsulfide complex (15.83 mmol, 7.91 mL) was then added
2. stirringstirring
3. waitwas continued at room temperature for a further 4 hours
4. customconsumption of starting material
5. additionMethanol was added cautiously until effervescence
6. addition2N hydrochloric acid (20 mL) was added
7. stirringThe mixture was stirred at room temperature for 20 hours
8. concentrationthen concentrated to dryness under reduced pressure
9. extractionThe residue was extracted with diethyl ether
10. washthe solution washed with water
11. dry with materialThe organic layer was dried with anhydrous sodium sulfate
12. customthe solvent removed under vacuum
13. dissolutionThe residue was dissolved in a mixture of dichloromethane and methanol, silica gel
14. additionwas added
15. customthe solvent removed under vacuum
16. washeluted with hexane-ethyl acetate (85:15)

ORD record

ord-1f6d7743036d46869687275ec57cebfa

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07919506B2