2-Chlorobenzoic acid chloride (7.0 g, 40.485 mmol, 10.0 eq.) was added at 0° C. to a solution of methyl 3-(tert-butylamino)-2,3-dihydro-1H-indene-5-carboxylate (A-16) (1.0 g, 4.0485 mmol, 1.0 eq.), DMAP (980 mg, 8.097 mmol, 2.0 eq.) and DIPEA (14 ml, 8.9716 mmol, 20.0 eq.) in acetonitrile (40 ml), and the mixture was then refluxed for 20 hours. After monitoring by TLC, the reaction solution was concentrated and the residue was taken up in ethyl acetate (300 ml), washed with sat. sodium hydrogen carbonate solution (100 ml), water (100 ml) and sat. NaCl solution (100 ml), dried over sodium sulfate, concentrated under reduced pressure and purified by column chromatography (silica gel, 10% ethyl acetate in hexane). Yield: 2.0 g
