Methyl iodomethane (23.64 g, 166.5 mmol) was added slowly and dropwise to a tetrahydrofuran (THF, 100 mL) solution of methyl 2-(4-methoxyphenyl)acetate (10.0 g, 55.49 mmol) at -78 °C. Subsequently, potassium tert-butoxide (KOt-Bu, 18.68 g, 166.5 mmol) was added in batches over 30 min, keeping the reaction mixture stirred at -78 °C for 1 h. The reaction was then brought to room temperature and continued to be stirred for 1 h. The reaction was completed by the addition of potassium tert-butoxide (KOt-Bu, 18.68 g, 166.5 mmol). Upon completion of the reaction, the reaction was quenched by the addition of water (25 mL) and extracted with ethyl acetate (EtOAc, 2 x 250 mL). The organic layers were combined, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to give methyl 2-(4-methoxyphenyl)-2-methylpropionate (10.46 g, 91% yield).
