4-(6-chloro-4-(ethoxycarbonyl) chroman-7-yloxy)benzoic acid (Preparation 1) (50 mg, 0.133 mmol), suspended in 1.3 ml of dichloromethane, was treated sequentially with (2,3-dihydro-1H-inden-2-yl)methanamine hydrochloride (26.8 mg, 0.146 mmol), N-ethyl-N-isopropylpropan-2-amine (32.4 μl, 0.186 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (30.5 mg, 0.159 mmol), and 1-hydroxy-7-azabenzotriazole (5.42 mg, 0.0398 mmol) at ambient temperature. After 16 hours, the reaction was applied directly to a silica gel column and eluted with a gradient (20% to 80%) of ethyl acetate-hexanes to provide the title compound (67 mg, 0.132 mmol, 99.8% yield) as a white solid.
