反应详情

A solution of ethyl 2,6-bis(trifluoromethyl)-4-hydroxy-3-pyridinecarboxylate (product of Example 3, 15 g, 0.0495 mol) in 5% aqueous sodium hydroxide (60 ml, 0.148 mol) was refluxed for 3 hours. The reaction was complete as judged by TLC (10% methanol in ethyl acetate). The mixture was then poured into a mixture of ice in concentrated aqueous hydrochloric acid and extracted with ethyl acetate. The ethyl acetate solution was dried over magnesium sulfate, and concentrated to give a light brown solid (13 g). It was treated with petroleum ether to give 11.9 g of a white solid (83%); mp 168°-172° C.

1. extractionextracted with ethyl acetate
2. dry with materialThe ethyl acetate solution was dried over magnesium sulfate
3. concentrationconcentrated