General procedure for the synthesis of 2-nitro-4,5-difluoroaniline from 2,4,5-trifluoronitrobenzene: Ammonia (15 mL) was added to a solution of 1,2,4-trifluoro-5-nitrobenzene (1) (5.00 g, 28.0 mmol, 1.00 eq.) in methanol (5 mL) and the mixture was transferred to a microwave reaction flask. The reaction mixture was placed in a microwave reactor and heated at 70 °C for 90 min. Upon completion of the reaction, the mixture was cooled to room temperature and the solvent was subsequently evaporated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (eluent: ethyl acetate/hexane, 1:4) to afford the target compound 2 (0.600 g, 12.0% yield) as a yellow solid. Thin layer chromatography (TLC) analytical conditions: 30% ethyl acetate/hexane (Rf value: 0.35); 1H NMR (500 MHz, CDCl3) data: δ 8.00 (t, J = 9.0 Hz, 1H), 6.65-6.58 (m, 1H), 6.08 (br s, 2H).
