Hydrochloric Acid → 1-(3,4-Difluoro-2-hydroxyphenyl)propan-1-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

30.1 g (161 mmol) of 2,3-difluorophenyl propionate in 16 ml of 1,2-dichlorobenzene are added dropwise to 21.5 g (161 mmol) of aluminum trichloride in 16 ml of 1,2-dichlorobenzene and the mixture is subsequently stirred at 100° C. for 6 hours. It is cooled, diluted with dichloromethane and poured cautiously onto a mixture of 2 M hydrochloric acid and ice. The phases are separated, extraction is carried out with dichloromethane and the extracts are washed with saturated sodium chloride solution and dried over sodium sulphate. The crude product is purified by column chromatography on silica gel (hexane/ethyl acetate 10-20%) to give 21.5 g of 1-(3,4-difluoro-2-hydroxyphenyl)propan-1-one. 21.4 g (115 mmol) of 1-(3,4-difluoro-2-hydroxyphenyl)propan-1-one are dissolved in 170 ml of acetone, and the solution is admixed with 29.5 g of potassium carbonate and 13 ml (209 mmol) of methyl iodide. The mixture is boiled under reflux for 4 hours and stirred at room temperature for 12 hours and then the solvent is largely removed. The residue is poured into water and subjected to extraction with diethyl ether. The extracts are washed with water, dried over sodium sulphate and, following the removal of the solvent in vacuo, give 21.2 g of 1-(3,4-difluoro-2-methoxyphenyl)propan-1-one.

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