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

Temperatur

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 600mL 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-Eintrag

ord-b466c0005f0b47ee8e84103baa622dc7

Quelldatensatz

uspto-grants-1997_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05599816