The general procedure for the synthesis of 2,5-dichlorophenylacetic acid from 2,5-dichlorophenylacetonitrile was as follows: concentrated sulfuric acid (8 mL) was added dropwise to a stirring solution of 2-(2,5-dichlorophenyl)acetonitrile (700 mg, 3.76 mmol, 1.00 equiv.) in water (6 mL). The reaction mixture was stirred in an oil bath at 110 °C for 3 hours. Upon completion of the reaction, the reaction solution was diluted with distilled water (100 mL) and subsequently extracted with dichloromethane (3 x 50 mL). The organic layers were combined, washed with saturated saline (3 x 100 mL) and dried with anhydrous sodium sulfate. Finally, the solvent was removed by concentration under reduced pressure to give 700 mg (91% yield) of 2,5-dichlorophenylacetic acid as a white solid.
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