Ethyl 2-(5-chloro-6-(2,2,2-trifluoroethoxy)-4′-(trifluoromethyl)biphenyl-3-yl)acetate (0.8 g, 1.81 mmol) was dissolved in anhydrous DMF (30 mL), NaH (60% wt. in paraffin oil, 0.109 g, 4.5 mmol) was added at 0° C. The reaction mixture was stirred for 30 min at room temperature and 1,4-dibromobutane (0.432 g, 1.99 mmol) was added drop wise at 0° C. The reaction mixture was stirred an additional 1 h at 0° C. upon which saturated NH4Cl solution (10 mL) was added. The reaction mixture was extracted with EtOAc (3×20 mL) and the combined organic phases were washed with water (3×20 mL) and brine (20 mL), and dried over MgSO4. The volatiles were removed under reduced pressure and the residue was purified by flash column chromatography to yield compound ethyl 1-(5-chloro-6-(2,2,2-trifluoroethoxy)-4′-(trifluoromethyl)biphenyl-3-yl)-cyclo pentane carboxylate (400 mg) as a thick liquid.
