General procedure for the synthesis of 2-chloro-3-hydroxybenzonitrile from 2-chloro-3-methoxybenzonitrile: Iodocyclohexane (3.86 mL, 29.83 mmol) was slowly added to a solution of DMF (10 mL) containing 2-chloro-3-methoxybenzonitrile (1 g, 5.97 mmol) at 20 °C under nitrogen protection. The reaction mixture was heated to 155 °C with continuous stirring for 7 hours. After the reaction was completed, it was cooled to room temperature and the mixture was poured into water. Extraction was carried out with ethyl acetate (2 x 50 mL), the organic phases were combined and washed with brine (50 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The crude product was ground with dichloromethane and the resulting solid was collected by filtration and dried under vacuum to give 2-chloro-3-hydroxybenzonitrile (0.510 g, 55.7% yield) as a white solid. No additional product was obtained from the filtrate treatment. The product was confirmed by 1H NMR (400 MHz, DMSO): δ 7.25-7.39 (3H, m), 11.00 (1H, s). The mass spectrum (ES-) showed m/z (M-H)- = 152.
