Ethanol → 3',4-Difluoro-[1,1'-biphenyl]-3-carboxylic acid

Temperature

80 °C

A 50 mL Schlenk tube was charged with (3-fluorophenyl)boronic acid (140 mg, 1.0 mmol), 5-bromo-2-fluorobenzoic acid (263 mg, 1.2 mmol), tetrakis(triphenylphosphine)palladium (0) (58 mg, 0.05 mmol) and cesium carbonate (1.3 g, 4.0 mmol). Ethanol (5 mL) and toluene (5 mL) were added and the tube was sealed and heated at 80° C. for 3 h. The cooled mixture was transferred to a flask, washing with ethanol, and concentrated in vacuo. The residue was diluted with water (10 mL) and extracted with EtOAc (2×10 mL). The aqueous phase was acidified with 1.0 N aqueous HCl (10 mL) and extracted with EtOAc (3×10 mL). The extracts were dried (Na2SO4), filtered and concentrated in vacuo. 1H-NMR showed the desired product, 3′,4-difluoro-[1,1′-biphenyl]-3-carboxylic acid, was slightly contaminated with 2-fluorobenzoic acid. The impure product (215 mg, ˜92%) was used without further purification.

1. customthe tube was sealed
2. customThe cooled mixture was transferred to a flask
3. washwashing with ethanol
4. concentrationconcentrated in vacuo
5. additionThe residue was diluted with water (10 mL)
6. extractionextracted with EtOAc (2×10 mL)
7. extractionextracted with EtOAc (3×10 mL)
8. dry with materialThe extracts were dried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe impure product (215 mg, ˜92%) was used without further purification

ORD record

ord-e17ba03d914e4f2489dd1bc8a3cd1a26

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09090584B2