反应详情

97 g (0.6 mole) of 2-methoxy-4,6-dimethylnicotinonitrile and 230 g of solid potassium hydroxide are dissolved in 1000 ml of ethanol and 120 ml of water and the solution is refluxed under nitrogen for 82 hours. The mixture is cooled, the precipitated substance collected by filtration, and the bulk of the ethanol is distilled off from the filtrate in vacuo. The residue is dissolved in 500 ml of water and extracted with methylene chloride. The alkaline aqueous phase is adjusted to pH 3.3 with concentrated hydrochloric acid and the precipitated crude product is collected by filtration. Recrystallisation of this crude product from ethanol yields pure 2-methoxy-4,6-dimethylnicotinic acid (m.p. 210°-215° C).

1. temperatureThe mixture is cooled
2. filtrationthe precipitated substance collected by filtration
3. distillationthe bulk of the ethanol is distilled off from the filtrate in vacuo
4. dissolutionThe residue is dissolved in 500 ml of water
5. extractionextracted with methylene chloride
6. customthe precipitated crude product
7. filtrationis collected by filtration
8. customRecrystallisation of this crude product from ethanol