Hydrochloric Acid → 2-Chloro-6-methylpyridin-3-ol

Temperatur

80 °C

In 500 ml conc. hydrochloric acid was dissolved 50.0 g (0.46 mole) 6-methyl-3-hydroxypyridine. After heating to 80° C., 150 ml 15% hydrogen peroxide was slowly added over several hours while maintaining the reaction temperature at 80°-85°. The reaction mixture was cooled to 50° C. and concentrated under reduced pressure. The residue was brought to pH 8 by careful addition of 25% sodium hydroxide solution. This mixture was extracted with ether. The solvent was removed and the residue recrystallized one time from water and one time from benzene to provide pure 2-chloro-6-methyl-3-hydroxypyridine, mp 190°-191° C.

1. temperaturewhile maintaining the reaction temperature at 80°-85°
2. temperatureThe reaction mixture was cooled to 50° C.
3. concentrationconcentrated under reduced pressure
4. additionThe residue was brought to pH 8 by careful addition of 25% sodium hydroxide solution
5. extractionThis mixture was extracted with ether
6. customThe solvent was removed
7. customthe residue recrystallized one time from water and one time from benzene

ORD-Eintrag

ord-1a543677da5144988b7c4bf06f929195

Quelldatensatz

uspto-grants-1980_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04220577