Sulfuric Acid → HCID 178516021, compound

Temperature

150 °C

2-Chloro-6-trifluoromethylpyridine (10.0 g; 55.1 mmol; 1 equiv) was charged to a 100 ml Hastelloy C Parr reactor, the reactor sealed and pressure tested with nitrogen. When a sealed system had been achieved, the pressure was released, the reactor resealed, and heated to 150° C. Potassium hydroxide solution (10% strength; 68.0 g; 121.1 mmol; 2.2 equiv) was added via an HPLC pump over 1 hour, while the mixture was maintained at 150° C. Addition of base caused the pressure to rise to 5 bar. The reaction mixture was held at this temperature and pressure for a further 5 hours. Following this period the reactor was cooled, dismantled and sodium chloride (5 g) added. The solution was cooled to 5° C., acidified to pH 5-6 by the addition of concentrated sulphuric acid, filtered and pulled dry. The filter cake was washed with water (10 g), pulled dry, discharged and allowed to dry overnight to afford 2-hydroxy-6-trifluoromethylpyridine as a colourless powder (9.5 g; 95% strength; 92% isolated yield).

1. customthe reactor sealed
2. temperaturewas maintained at 150° C
3. additionAddition of base
4. waitFollowing this period
5. temperaturethe reactor was cooled
6. temperatureThe solution was cooled to 5° C.
7. filtrationfiltered
8. custompulled dry
9. washThe filter cake was washed with water (10 g)
10. custompulled dry
11. customto dry overnight
12. customto afford

ORD record

ord-44c57c9e111f4d979f933f36fbacc467

Source dataset

uspto-grants-1999_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05973159