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

Temperature

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 record

ord-1a543677da5144988b7c4bf06f929195

Source dataset

uspto-grants-1980_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04220577