A solution of (2-(benzyloxy)-3-tert-butylphenyl)(3-(pyridin-2-yl)phenyl)methanone (0.96 g, 2.28 mmol) in anhydrous tetrahydrofuran (20 mL) was stirred at −78° C. under nitrogen and 1.8 M phenyllithium (2 mL, 3.6 mmol) was added at such a rate that the temperature did not exceed −70° C. Stirring was continued at −78° C. for 30 min for 1 hr at room temperature. The reaction mixture was poured on saturated ammonium chloride (150 mL) and extracted with ethyl acetate (150 mL). The organic extract was washed with water (2×100 mL), dried over sodium sulfate and stripped. The crude product was purified by chromatography on silica (60 g) with 5% ethyl acetate in heptane (1 L), then 7.5% (2 L) to afford 6 (1.14 g, 100%). This material contains a minor impurity and it was used as such in the next step.
