2-(4-Fluorophenyl)acetic acid → 4-Fluorophenylacetyl chloride

Temperatur

60 °C

4-Fluorophenylacetic acid [starting compound B] (15 g) was dissolved in thionyl chloride (15 ml) to prepare a solution which was then heated at 60° C. for one hr. Excess thionyl chloride was removed by evaporation under the reduced pressure to give 4-fluorophenylacetyl chloride. The acid chloride was dissolved in acetone (200 ml). Ammonium acetate (112 g) was added to the solution, and the mixture was stirred at room temperature for 17 hr. An aqueous saturated sodium hydrogencarbonate solution (150 ml) was added thereto, and the mixture was stirred at room temperature for one hr. The reaction solution was then extracted with chloroform, and the solvent in the extract was removed by evaporation to give a crude crystal. The resultant crude crystal was washed with a hexane/ethyl acetate (2/1) mixed solution to give 4-fluorophenylacetamide (10.5 g, yield 70%).