To a solution of 3-(1H-indol-3-yl)propanoic acid (5 g, 0.026 mol) in DMF (20 mL) was added at 0° C. sodium hydride (2.11 g, 0.088 mol), the mixture was stirred some minutes at 0° C. and (2-bromoethoxy)(tert-butyl)dimethylsilane (5.67 mL, 0.026 mol) was added. The reaction mixture was stirred overnight at room temperature. The crude mixture was poured into a sodium sulphate saturate solution and extracted with ethyl acetate. The solvent was removed under reduced pressure and the crude obtained was purified over silica gel eluting with hexane:ether (100/0 to 0/100) to obtain the title compound (4g, 43%).
