General procedure for the synthesis of 2-chloro-4-methoxynitrobenzene from 5-methoxy-2-nitrobenzoic acid: to a Silak reaction tube equipped with a magnetic stirrer, 6.2 mg of silver sulfate, 36.3 mg of copper acetate, 12.5 mg of 2,9-dimethyl-1,10-o-phenanthroline, 39.4 mg of 5-methoxy-2-nitrobenzoic acid and 17.5 mg of NaCl, dissolved in 4 mL of dimethyl sulfoxide. The reaction system was heated at 160°C for 24 hours under oxygen atmosphere. After completion of the reaction, the reaction was quenched by addition of distilled water and extracted with ethyl acetate three times at 10 mL each. the organic phases were combined and concentrated to give 25.1 mg of 2-chloro-4-methoxynitrobenzene in 67% yield.
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