To a solution of 43 mg (0.22 mmol) of 5-chloro-1H-indole-7-carboxylic acid and 70 mg of TBTU (0.22 mmol) in 3 ml DMF, were added 0.19 ml (1.1 mmol) of N,N-diisopropylethyl amine. After stirring for 5 min at rt, 81 mg (0.22 mmol) of [rac]-(4-tert-butyl-benzyl)-[2-(4-fluoro-phenyl)-2-hydroxy-ethyl]-amine were added. After stirring for 17 h at rt, the reaction mixture was diluted with 30 ml water and extracted with EtOAc (2×). The combined organic phases were washed with water and brine, dried with magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography (8 g silica gel; heptane/EtOAc 2:1) to give 63 mg (55%) of a light yellow foam. MS (ISP) 479.4 (M+H)+.
