Water → 2,3-Difluoro-5-hydroxybenzoic acid

Tetrabutylammonium fluoride trihydrate (191 g, 731.8 mmol) was added in portions to a solution of 2,3-difluoro-5-(triisopropylsilyloxy)benzoic acid (99.13 g, 300.0 mmol) in tetrahydrofuran (500 mL), and the resulting mixture stirred overnight at room temperature. The reaction mixture was poured into water (1000 mL) and extracted with ethyl acetate (2×500 mL). The combined organic layers were washed with brine (2×500 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to afford 2,3-difluoro-5-hydroxybenzoic acid (50 g, 95%) as a light yellow solid. MS (ESI, neg. anion) m/z 173 [M−H]−.

1. extractionextracted with ethyl acetate (2×500 mL)
2. washThe combined organic layers were washed with brine (2×500 mL)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under vacuum

ORD record

ord-a451b73a7ca346ab8b3dfb3a9aaf9b1a

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388161B2