反应详情

21.3 g of potassium carbonate powder, 1.5 g of finely powdered potassium iodide and 16 g of 2-chloroethylcarbamic acid methyl ester are added to a solution of 17.1 g of 4-(3,5-difluorophenoxy)-phenol in 100 ml of dimethylformamide, and the reaction mixture is heated at +95° C. for 15 hours. The reaction mixture is then cooled, poured onto ice-water and extracted repeatedly with ether. The combined ether phases are washed with water and dried over sodium sulfate. The solvent is distilled off completely. The crude product is purified further by chromatography over silica gel (eluant: petroleum ether (40° C.-65° C.)/diethyl ether, 5:1), yielding 2-[4-(3,5-difluorophenoxy)-phenoxy]-ethylcarbamic acid methyl ester, n21D : 1.5394.

1. temperaturethe reaction mixture is heated at +95° C. for 15 hours
2. temperatureThe reaction mixture is then cooled
3. additionpoured onto ice-water
4. extractionextracted repeatedly with ether
5. washThe combined ether phases are washed with water
6. dry with materialdried over sodium sulfate
7. distillationThe solvent is distilled off completely
8. customThe crude product is purified further by chromatography over silica gel (eluant: petroleum ether (40° C.-65° C.)/diethyl ether, 5:1)