反应详情

6.68 g (0.0305 mol) of 2-methyl-6-trifluoromethyl-nicotinic acid methyl ester (prepared in the manner described in Heterocycles, 46, 129 (1997)) are dissolved in 250 ml of methanol/water (3:1 mixture) and 1.92 g (0.046 mol) of lithium hydroxide hydrate are added in portions at 22° C. After 4 hours at 22° C., the reaction mixture is added to ethyl acetate and 2N hydrochloric acid; the organic phase is washed three times with water, dried with sodium sulfate and concentrated by evaporation, and the residue is triturated with a small amount of hexane. After filtering, 5.69 g (90% of theory) of the expected 2-methyl-6-trifluoromethyl-nicotinic acid having a melting point of 147-149° C. are obtained.

1. washthe organic phase is washed three times with water
2. dry with materialdried with sodium sulfate
3. concentrationconcentrated by evaporation
4. customthe residue is triturated with a small amount of hexane
5. filtrationAfter filtering