5-Chloro-2-nitrobenzoic acid

73033-58-6

2516-95-2

Fe(NO3)3-9H2O (40.6 mg, 0.1 mmol), TEMPO (15.8 mg, 0.1 mmol), KCl (7.5 mg, 0.1 mmol) and 5-chloro-2-nitrobenzenemethanol (108.5 mg, 1.0 mmol) were added sequentially to the Schlenk tube. Under oxygen atmosphere, DCE (4.0 mL) was added (using a gas bag, commercial size: 2 L, expandable to 5 L). The reaction mixture was stirred at 25 °C and the progress of the reaction was monitored by TLC (unfolding agent: petroleum ether/EtOAc = 5:1) until the reaction was complete (~48 h). After completion of the reaction, the crude reaction mixture was filtered through a short silica gel column (height: 2 cm, diameter: 3 cm) and eluted with Et2O (3 × 25 mL). After evaporation of the solvent, the residue was purified by silica gel column chromatography [eluent: petroleum ether/EtOAc = 15:1 (500 mL) to 2:1 (300 mL)] to afford 5-chloro-2-nitrobenzoic acid (69.9 mg, 57% yield) as a pale yellow solid. The yield of 5-chloro-2-nitrobenzoic acid in the crude product was determined to be 57% by NMR analysis, using CH2Br2 as an internal standard and comparing the spectral data with those reported in the literature, while 5-chloro-2-nitrobenzaldehyde was detected in 38% yield.