反应详情

Methyl 2,6-dimethyl-4-trifluoromethylpyridine-3-carboxylate (23.30 g, 99.9 mmol) was dissolved in ethanol (50 mL). A 5-mol/L aqueous potassium hydroxide solution (50 mL, 250 mmol) was added to the solution, followed by refluxing for 2 days. The reaction mixture was allowed to stand for cooling, and concentrated hydrochloric acid (15 mL) was added to the resultant mixture, followed by concentration under reduced pressure. To the obtained residue, ethanol was added, and the mixture was heated for dissolution. Insoluble matter was removed through filtration, and the filtrate was concentrated under reduced pressure. Ether was added to the thus-obtained residue, and the solid was collected through filtration, to thereby yield 2,6-dimethyl-4-trifluoromethylpyridine-3-carboxylic acid hydrochloride as a colorless powder (25.24 g, 99%).

1. temperatureby refluxing for 2 days
2. temperaturefor cooling
3. concentrationfollowed by concentration under reduced pressure
4. additionTo the obtained residue, ethanol was added
5. temperaturethe mixture was heated for dissolution
6. customInsoluble matter was removed through filtration
7. concentrationthe filtrate was concentrated under reduced pressure
8. additionEther was added to the thus-obtained residue
9. filtrationthe solid was collected through filtration