Triphenylphosphine → 4-(4-(Trifluoromethyl)phenyl)pyridine 1-oxide

A solution of 4-(trifluoromethyl)phenylboronic acid (1.78 g, 9.37 mmol) in DME (10 mL) and aqueous K2CO3 (12 mL, 1.8 M) was degassed with argon for 20 minutes. Triphenylphosphine (797 mg, 3.04 mmol), palladium(II)acetate (174 mg, 0.775 mmol), and 4-chloropyridine 1-oxide (1.00 g, 7.72 mmol) were added sequentially, and the mixture was heated to reflux under an argon atmosphere. After stirring at reflux for 14 h, the mixture was allowed to cool and then filtered. The filtrate was diluted with H2O (25 mL) and extracted with EtOAc (3×25 mL). The organics were dried over Na2SO4, filtered and concentrated to dryness. Purification by flash column chromatography (silica gel, CH2Cl2/MeOH, 95:5) gave the title compound (465 mg, 25%) as white crystals: 1H NMR (500 MHz, CDCl3) δ 8.29 (d, J=7.2 Hz, 2H), 7.75 (d, J=8.3 Hz, 2H), 7.69 (d, J=8.2 Hz, 2H), 7.52 (d, J=7.2 Hz, 2H); ESI MS m/z 240 [M+H]+.

1. temperaturethe mixture was heated
2. temperatureto reflux under an argon atmosphere
3. temperatureat reflux for 14 h
4. temperatureto cool
5. filtrationfiltered
6. additionThe filtrate was diluted with H2O (25 mL)
7. extractionextracted with EtOAc (3×25 mL)
8. dry with materialThe organics were dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated to dryness
11. customPurification by flash column chromatography (silica gel, CH2Cl2/MeOH, 95:5)

ORD record

ord-cfeede2c30e745a99b7ebc5896d63fd7

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08273770B2