To a solution of 4-(((1S,2S)-1-hydroxy-2,3-dihydro-1H,1′H-[2,2′-biinden]-2-yl)methyl)benzoic acid (100 mg, 0.26 mmol) and K2CO3 (72 mg, 0.52 mmol) in DMF (2.5 mL), was added EtI (81 mg, 0.52 mmol) and then stirred at room temperature for 4 h. The reaction mixture was diluted with 1.5 N HCl (50 mL) and extracted with ethyl acetate (3×25 mL). The organic layer was washed with 10% aq. NaHCO3 (25 mL), brine (25 mL), dried over anhydrous Na2SO4 and evaporated under reduced pressure. The residue was purified by CombiFlash using 20% ethyl acetate in chloroform as an eluent to yield 55 mg (50%) of the title compound as an off white solid.
