To a stirred solution of 2-chloro-5-nitrobenzoyl chloride (5.03 g, 22.9 mmol) and triethylamine (3.51 mL, 25.1 mmol) in dichloromethane (CH2Cl2) maintained at 0°C in a nitrogen atmosphere was slowly added aniline (2.19 mL, 24.0 mmol) dropwise. The reaction mixture was continued to be stirred at 0 °C for 5 min, then brought to room temperature and stirred for 15 min. Upon completion of the reaction, the solution was diluted with ethyl acetate (EtOAc, 300 mL) and washed sequentially with 1.0 M HCl, water, 1.0 M NaHCO3 and saturated saline (100 mL each). The organic phase was dried over anhydrous magnesium sulfate (MgSO4) and concentrated by rotary evaporation to give a light yellow solid (5.32 g). The solid was purified by recrystallization from ethyl acetate to give a white solid 2-chloro-5-nitro-N-phenylbenzamide (3.34 g, 53% yield) with a melting point of 155-156 °C. The product was confirmed by 1H NMR (CDCl3, 400 MHz): δ 8.63 (d, 1H, J=2.7 Hz), 8.28 (dd, 1H, J=2.7, 8.9 Hz), 7.81 (br s, 1H), 7.68-7.63 (m, 3H), 7.42 (t, 2H, J=7.9 Hz), 7.23 (t, 1H, J= 7.5 Hz). The mass spectrum (ES-) showed m/z 275.1 ([M-H]-). Elemental analysis (C13H9ClN2O3) calculated values: C, 56.43; H, 3.28; N, 10.13; measured values: C, 56.33; H, 3.30; N, 10.03.
