To a solution of 5.33 g (18.24 mmol) of (1S,2R)-2-(3-chlorophenyl)-1-(4-chlorophenyl)but-3-en-1-amine (Example 115, Step E) in DCM (45.0 mL) was added N,N-diisopropylethylamine (4.8 mL, 27.5 mmol), followed by trans-beta-styrenesulfonyl chloride (4.17 g, 20.58 mmol). The resulting solution was stirred at ambient temperature under an N2 atmosphere. After being stirred for 3.25 hours, the reaction was diluted with water and extracted with DCM. The combined organic layers were washed with sat. aq. NaCl solution, dried over Na2SO4, filtered and the filtrate was concentrated. Purification by flash chromatography on silica gel (0 to 40% EtOAc in hexanes gradient) provided the title compound as a yellow solid.
