Sulfuric Acid → 2,2-Bis(4-fluorophenyl)acetic acid

Temperature

80 °C

Fluorobenzene (13.6 g, 0.142 mol) and glyoxylic acid monohydrate (2.35 g, 0.0255 mol) were dissolved in warm acetic acid (30.0 mL). The mixture was cooled in an ice/water bath and concentrated sulfuric acid (20.0 mL) was added dropwise over 0.5 h. The resulting thick red suspension was stirred at 80° C. for 12 h and then cooled to room temperature. Water (300 mL) was added and the pH was adjusted to 3 with potassium hydroxide pellets and 10% KOH solution. The aqueous solution was extracted with ethyl acetate (3×100 mL) and the combined organic extracts were washed with brine (100 mL) and dried over sodium sulfate, filtered and concentrated in vacuo to give the desired product (5.18 g, 82%) as a red solid, which was used in the subsequent step without further purification: 1H NMR (400 MHz, CD3OD) δ 9.45 (br s, 1H), 7.31–7.25 (m, 4H), 7.06–7.0 (m, 4H), 5.01 (s, 1H).

1. temperatureThe mixture was cooled in an ice/water bath
2. temperaturecooled to room temperature
3. extractionThe aqueous solution was extracted with ethyl acetate (3×100 mL)
4. washthe combined organic extracts were washed with brine (100 mL)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo

ORD record

ord-7330a78fa7104f73badf4df37141e16a

Source dataset

uspto-grants-2007_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07199135B2