Hydrogen Peroxide → 5-Fluoro-2-methylpyridine 1-oxide

Temperature

50 °C

To the solution of 5-fluoro-2-picoline obtained in Step 4, at 0° C., was added, with vigorous stirring, a cold solution of 40% peracetic acid (prepared by carefully adding 50 mL of 30% hydrogen peroxide solution to 150 mL of glacial acetic acid). The reaction mixture was heated at reflux temperature (50° C.) for 4 days and then poured into 600 mL of ice water. The aqueous mixture was adjusted to pH 9 by the addition of potassium carbonate and then was stirred at ambient temperature for 4 hours. The aqueous solution was continuously extracted with methylene chloride for 24 hours and the methylene chloride extract was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to afford 30.8 g (22% yield) of the title compound; MS DCI-NH3M/Z: 128 (M+H)+ base; 1H NMR (CDCl3) d 2.48 (s, 3H), 7.00 (ddd, 1H), 7.22 (dd, 1H), 8.22 (dd, 1H).

1. temperatureThe reaction mixture was heated
2. extractionThe aqueous solution was continuously extracted with methylene chloride for 24 hours
3. extractionthe methylene chloride extract
4. dry with materialwas dried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo

ORD record

ord-c5f292609ba64fafa75e76f067d6b75e

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05726182