To a solution of 6.72 g (20.92 mmol) of (5R,6S)-5-(3-chlorophenyl)-6-(5-chloropyridin-2-yl)piperidin-2-one (Example 121, Step F) in DMF (˜0.5M) at 0° C. was slowly added a dispersion of 60% sodium hydride in mineral oil (2.51 g, 62.8 mmol). The reaction was stirred 0° C. for 30 min, followed by addition of 1-(chloromethyl)-2,4-dimethoxybenzene (7.81 g, 41.8 mmol). Upon completion, the reaction was quenched at 0° C. with a small excess of acetic acid (4.79 mL, 84 mmol). It was neutralized with sat. aq. NaHCO3 solution and extracted with ethyl acetate. The organic layer was dried over Na2SO4, filtered and the filtrate as concentrated under reduced pressure to yield a reddish oil. Purification by flash chromatography on silica gel (eluent: 0 to 30% ethyl acetate/DCM, gradient elution) provided the title compound as a pale yellow oil.
