General procedure for the synthesis of 2-amino-3-chlorophenol from 2-nitro-3-chlorophenol: 3-chloro-2-nitrophenol (2.5 g, 14.5 mmol) was dissolved in ethanol (30 mL) at room temperature, followed by the addition of tin chloride dihydrate (SnCl2-2H2O, 13 g, 57.8 mmol). The reaction mixture was heated to 90°C and stirred continuously for 2 hours. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming the completion of the reaction, the reaction mixture was cooled to room temperature and concentrated under reduced pressure. Ice water (50 mL) was added to the concentrated residue and the pH was adjusted with ammonia solution to 7. Subsequently, extraction was performed with ethyl acetate (3 x 50 mL). The organic layers were combined, washed with saturated saline (50 mL), dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The residue obtained was ground with hexane (25 mL) to give 2-amino-3-chlorophenol as an off-white solid. Yield: 1.8 g (80% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6) and mass spectrometry (ESI+): 1H NMR δ 9.58 (broad single peak, 1H), 6.69 (double peaks, J = 8.0 Hz, 1H), 6.63 (double peaks, J = 8.0 Hz, 1H), 6.38-6.48 (multiple peaks, 1H), 4.05 (broad single peaks, 2H); mass spectra ( ESI+) m/z 144.09 [M + H]+.
