4-(4-Biphenylylmethoxy)phenylacetic acid (1.51 g), tert-butyl 2-aminoethyl(methyl)carbamate (826 mg), WSC (1 g), 1-hydroxybenzotriazole (798 mg), and triethylamine (2.2 ml) were added to THF (90 ml). The reaction mixture was stirred at room temperature for 20 hr and poured onto water, followed by extraction with ethyl acetate-THF (1:1). The organic layer was washed with water, saturated aqueous sodium bicarbonate, and saturated aqueous sodium chloride sequentially, dried with sodium sulfate, and concentrated. The residue was purified by alumina column chromatography (eluent; methanol:THF=1:1) followed by recrystallization from THF-IPE gave the titled compound (888 mg).
