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Step 1: A mixture of 4-bromo-2-methoxy-6-methylphenol (146a, 100 mmol) and cuprous cyanide (CuCN, 200 mmol) in dimethylsulfoxide (DMSO, 50 mL) was reacted at 150 °C with stirring overnight. Upon completion of the reaction, the mixture was poured into a mixture of water (200 mL) and ethyl acetate (EtOAc, 200 mL). The precipitate was collected by filtration and the filtrate was separated. The aqueous layer was extracted with ethyl acetate (EtOAc). All organic extracts were combined, dried with anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The residue was purified by silica gel (SiO2) column chromatography to afford the target product 4-hydroxy-3-methoxy-5-methylbenzonitrile (146b, yield: 71.6%).