Diglyme → 2-(2,2-Difluorocyclopropyl)-acetic acid 2-(4-phenoxyphenoxy)-ethyl ester

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Reaction Steps

14.8 g of 3-butenoic acid 2-(4-phenoxyphenoxy)-ethyl ester are dissolved in 30 ml of diethylene glycol dimethyl ether (diglyme), and the solution is heated to +165° C. with stirring. A solution of 15.25 g of the sodium salt of chlorodifluoroacetic acid in 30 ml of diglyme is then added dropwise at that temperature over a period of 8 hours. The mixture is stirred for a further one hour at +165° C. and then cooled to room temperature. The reaction mixture is filtered, the residue is washed with 20 ml of diglyme and the filtrate is concentrated completely by evaporation and then taken up in 40 ml of diethyl ether, washed twice with 20 ml of water each time and dried over sodium sulfate. The solvent is concentrated by evaporation and the oily residue is then purified by column chromatography on silica gel with hexane/ethyl acetate (9:1), yielding 12.1 g of 2-(2,2-di-fluorocyclopropyl)-acetic acid 2-(4-phenoxyphenoxy)-ethyl ester in the form of a colourless oil having a refractive index of nD22 : 1.5309.

Provenance & Evidence