反应详情

To a stirred mixture of 21.6 g (0.11 mol) of 2-(4-hydroxyphenoxy)-propionic acid methyl ester, 15.2 g (0.11 mol) of potassium carbonate, 1.45 g (0.0055 mol) of 18-Crown-6 ether and 100 ml of acetonitrile is added dropwise a solution of 14.95 g (0.10 mol) of 5-chloro-2,3-difluoropyridine in 30 ml of acetonitrile and the mixture is heated at a temperature of 50° to 60° C. during 40 hours. The mixture is then poured into ice/water. The organic material is extracted with ethyl acetate, washed with a saturated salt solution, dried over magnesium sulfate, filtered and evaporated. The oily residue is purified by chromatography over a silica gel column with a hexane/ethyl acetate 3:1 solvent. After evaporation of the solvent one obtain 20.4 g of the above ester (63% of the theory) is obtained in crystalline form. The melting point is 63°-64° C.

1. temperaturethe mixture is heated at a temperature of 50° to 60° C. during 40 hours
2. extractionThe organic material is extracted with ethyl acetate
3. washwashed with a saturated salt solution
4. dry with materialdried over magnesium sulfate
5. filtrationfiltered
6. customevaporated
7. customThe oily residue is purified by chromatography over a silica gel column with a hexane/ethyl acetate 3:1 solvent
8. customAfter evaporation of the solvent one