2-Nitro-3-(trifluoromethoxy)pyridine (370 mg, 1.78 mmol) was used as a raw material and dissolved in ethanol (5 mL) under stirring. Subsequently, aqueous ammonium chloride (951 mg, 17.78 mmol, dissolved in 10 mL of water) and iron powder (993 mg, 17.78 mmol) were added to this solution. The reaction mixture was heated to 70 °C and maintained at this temperature for 2 hours. Upon completion of the reaction, the mixture was cooled to room temperature, filtered to remove the solids, and the solids were washed with ethyl acetate. The filtrate was concentrated to dryness under vacuum. The residue was diluted with water and extracted with ethyl acetate (3 x 15 mL). The organic layers were combined and dried over anhydrous sodium sulfate and subsequently concentrated to dryness under vacuum. The resulting residue was used directly in the next step of the reaction without further purification (yield: 250 mg, yield: 79%). The product was confirmed by NMR hydrogen spectrum (400 MHz, DMSO-d6): δ 7.93-7.91 (m, 1H), 7.48-7.46 (m, 1H), 6.59-6.56 (m, 1H), 6.35 (brs, 2H).
