Step 1. Synthesis of methyl 3-methoxyphenylacetate
Trimethylmethylsilyl chloride (182 g, 1.68 mol) was slowly added dropwise to a solution of 3-methoxyphenylacetic acid (127 g, 0.77 mol) in methanol (1.0 L) over 1.1 hours. The reaction mixture was stirred at room temperature for 17.25 hours. Upon completion of the reaction, the mixture was concentrated under vacuum, dissolved in ethyl acetate and dried with anhydrous magnesium sulfate. Subsequently, the solution was concentrated under vacuum to afford the brown oily product methyl 3-methoxyphenylacetate (133 g, 97% yield). The structure of the product was confirmed by 1H NMR (CDCl3, 300 MHz): δ 7.24 (t, 1H, J = 7.5 Hz), 6.83 (m, 3H), 3.80 (s, 3H), 3.69 (s, 3H), 3.60 (s, 2H).