1.2 mL (7.43 mmol, 2 eq) of heptyl isocyanate are added to a solution of 1.0 g (3.7 mmol, 1 eq) of methyl 3-(3′-methylaminobiphenyl-4-yl)propanoate (obtained as in 4c) in 15 mL of a 4/1 tetrahydrofuran/triethylamine mixture. The reaction mixture is stirred for 12 hours at 40° C. The reaction is stopped by addition of 10 mL of water and then extracted with ethyl acetate. The organic phases are combined and dried over sodium sulfate. The solvents are evaporated off and the residue is then chromatographed on silica gel (70/30 heptane/ethyl acetate). 1.15 g of methyl 3-[3′-(1-methyl-3-heptyl-ureido)biphenyl-4-yl]propanoate are obtained. Yield=76%
