To a mixture of 2-trimethylsilanylethyl (4-amino-3-benzyloxyphenoxy)acetate (4.56 g, 12.2 mmol) and potassium carbonate (3.37 g, 24.4 mmol) in DMF (25 mL) is added methyl bromoacetate (1.87 g, 12.2 mmol). The mixture is stirred at 60° C. for 1 h then is allowed to cool to RT. It is poured into water and extracted with EtOAc and the organic phase is washed with water (1×), brine (5×), and dried over Na2SO4. The solvent is removed under reduced pressure to afford the title compound which is used directly in the next step.
