4-(4-Hydroxyphenyl)-N-benzyloxycarbonylbutylamine (29) (1.0 g, 3.3 mmol), 1-bromo-2-(2-methoxyethoxy)ethane (0.67 g, 3.7 mmol), and potassium carbonate (0.60 g, 4.3 mmol) were combined in acetone (20 mL), and stirred at reflux overnight. The reaction was allowed to cool, and then filtered and evaporated. The residue was re-subjected in methyl ethyl ketone (10 mL), 1-bromo-2-(2-methoxyethoxy)ethane (0.91 g, 5.0 mmol), potassium carbonate (0.74 g, 5.3 mmol), and sodium iodide (0.5 g, 3.3 mmol) with stirring at reflux for 2.5 h. The reaction was allowed to cool, and was filtered and evaporated. The residue was re-subjected in DMF (10 mL), with 1-bromo-2-(2-methoxyethoxy)ethane (1.8 g, 9.8 mmol), potassium carbonate (1.60 g, 11.6 mmol), and sodium iodide (0.4 g, 2.7 mmol), overnight with stirring at 70° C. The reaction was evaporated to remove the solvent and then was dissolved in ethyl acetate (70 mL). The organic extract was washed with water (3×20 mL), dried over potassium carbonate and filtered. Evaporation afforded 1.1 g of an oil which was purified by column chromatography (silica gel, 2:1 hexanes/ethyl acetate) to afford 800 mg (70%) of pure product 106. 1H NMR (300 MHz, CDCl3) δ 1.42-1.68 (m, 4H), 2.55 (t, J=7.5 Hz, 2H), 3.20 (q, J=6.2 Hz, 2H), 3.39 (s, 3H), 3.55-3.60 (m, 2H), 3.69-3.74 (m, 2H), 3.82-3.87 (m, 2H), 4.11 (t, 5.3 Hz, 2H), 4.71 (br s, 1H), 5.09 (s, 2H), 6.82 (d, J=8.5 Hz, 2H), 7.05 (d, J=8.5 Hz, 2H), 7.34 (s, 5H). CI MS m/z=402 [C23H31NO5+H]+.
