Synthesis
General procedure: Preparation of 3-hydroxy-2-methylbenzonitrile (Compound 74): 3-methoxy-2-methylbenzonitrile (1 g, 6.79 mmol) and tetra-n-butylammonium iodide (4.12 g, 17 mmol) were dissolved in dichloromethane (15 mL), the solution was cooled to -78 °C and purged with nitrogen. Boron trichloride (1 M solution in dichloromethane, 17 mL, 17 mmol) was added dropwise at -78 °C and the mixture was then stirred at -78 °C for 15 min, followed by warming to room temperature and continued stirring for 3 hours. Upon completion of the reaction, the reaction mixture was quenched with water, stirred for 30 minutes and subsequently concentrated under vacuum. The aqueous residue was extracted with ether, the organic phases were combined and washed five times with water, dried with magnesium sulfate and finally concentrated under vacuum to give 3-hydroxy-2-methylbenzonitrile as a brown solid in 91% yield (826 mg). The product was confirmed by 1H NMR (400 MHz, CDCl3): δ 2.20 (s, 3H), 7.10 (m, 1H), 7.20 (d, 1H), 10.10 (s, 1H); LRMS APCI m/z 132 [M-H]-.
