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General procedure for the synthesis of 2-chloro-3-fluoronitrobenzene from 3-fluoronitrobenzene: To a solution of 3-fluoronitrobenzene (2 g, 14.2 mmol) in tetrahydrofuran (THF, 30 mL) was slowly added a solution of N-chlorosuccinimide (5.69 g, 42.6 mmol) in THF (20 mL) at -78 °C. Subsequently, NaHMDS (28.4 mL, 28.4 mmol) in a 1 M solution of THF was added dropwise while ensuring that the internal temperature of the reaction system was maintained below -75 °C. The reaction mixture was stirred continuously at -78 °C for 30 min. Upon completion of the reaction, the mixture was partitioned between 5% hydrochloric acid and ethyl acetate. The organic layers were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and the solvent evaporated. The resulting solid was purified by silica gel column chromatography with the eluent being a hexane solution of 20% ethyl acetate, resulting in the target product 2-chloro-3-fluoronitrobenzene (231 mg, 9.2% yield). The structure of the product was confirmed by EI-MS, m/z 176.5 (M+).