Potassium Carbonate → 4-Phenylpyridin-2-ol

A solution of 4-phenylpyridine-1-oxide (2.00 g, 0.012 mol) in acetic anhydride (6 mL) was heated at reflux for 48 hours. The reaction mixture was cooled to ambient temperature, diluted with ethyl acetate (80 mL) and washed with saturated aqueous sodium bicarbonate (2×15 mL) and brine (15 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was dissolved in methanol (20 mL) and potassium carbonate (0.32 g, 0.002 mol) was added to the solution. The reaction mixture was stirred at ambient temperature for 1 hour, then diluted with chloroform (100 mL) and filtered through Celite. The filtrate was concentrated in vacuo. The residue was dissolved in a mixture of methanol/chloroform 1/10 (30 mL). The title compound was precipitated with the addition of hexanes (30 mL) as a white solid which was collected by filtration (1.20 g, 60%): 1H NMR (300 MHz, DMSO-d6) δ 7.66-7.62 (m, 2H), 7.48-7.37 (m, 4H), 6.51 (d, J=1.2 Hz, 1H), 6.44 (dd, J=6.7, 1.8 Hz, 1H); MS (ES+) m/z 172.5 (M+1).

1. temperatureat reflux for 48 hours
2. washwashed with saturated aqueous sodium bicarbonate (2×15 mL) and brine (15 mL)
3. dry with materialThe organic layer was dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. dissolutionThe residue was dissolved in methanol (20 mL)
7. filtrationfiltered through Celite
8. concentrationThe filtrate was concentrated in vacuo
9. dissolutionThe residue was dissolved in a mixture of methanol/chloroform 1/10 (30 mL)
10. customThe title compound was precipitated with the addition of hexanes (30 mL) as a white solid which
11. filtrationwas collected by filtration (1.20 g, 60%)

ORD record

ord-5410db40f9124c09a86201f5af1b81eb

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08501746B2