Acetic Anhydride → 2-Hydroxy-4-(4-trifluoromethylphenyl)pyridine

Participants

Reaction Steps

A stirred solution of 4-(4-(trifluoromethyl)phenyl)pyridine 1-oxide (465 mg, 1.94 mmol) in Ac2O (10 mL) under nitrogen atmosphere was heated from 110 to 130° C. over 4.5 h. Then the mixture was heated at reflux for 2 h and then allowed to cool. The mixture was concentrated to dryness and then treated with MeOH and water (10 mL, 1:1). After stirring at room temperature for 6 h, the mixture was heated to reflux for 2.5 h. The mixture was allowed to cool and was concentrated to dryness. Purification by flash column chromatography (silica gel, CH2Cl2/MeOH, 95:5) gave the title compound (336 mg, 72%) as a light brown powder: 1H NMR (500 MHz, CDCl3) δ 12.67 (br s, 1H), 7.76 (d, J=8.2 Hz, 2H), 7.69 (d, J=8.3 Hz, 2H), 7.47 (d, J=6.8 Hz, 1H), 6.80 (d, J=1.6 Hz, 1H), 6.54 (dd, J=6.8, 1.8 Hz, 1H); ESI MS m/z 240 [M+H]+.

Provenance & Evidence