To a mixture of (2-amino-thiazol-5-ylsulfanyl)-acetic acid methyl ester (403 mg, 1.98 mmol) in CH2Cl2 (100 mL) was added CDI (480.2 mg, 2.96 mmol) and DMAP (25 mg, 0.20 mmol) at room temperature. The reaction mixture was stirred at room temperature for 1.5 h, and then (2,2-difluoro-2-phenyl-ethyl)-(4-methyl-cyclohexyl)-amine (500 mg, 1.98 mmol) was added. The mixture was stirred for 16 h at room temperature. The solvent was removed at reduced pressure and the residue was purified by preparative HPLC to give {2-[3-(2,2-difluoro-2-phenyl-ethyl)-3-(4-methyl-cyclohexyl)-ureido]-thiazol-5-ylsulfanyl}-acetic acid methyl ester.
