To a mixture of (2-amino-thiazol-5-ylsulfanyl)-acetic acid methyl ester (416 mg, 2.04 mmol) in CH2Cl2 (30 mL) was added CDI (496 mg, 3.06 mmol) and DMAP (25 mg, 0.21 mmol) at room temperature. The reaction mixture was stirred at rt for 1.5 h, then (4-methyl-cyclohexyl)-(2-methyl-2-phenyl-propyl)-amine (500 mg, 2.04 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-(4-methyl-cyclohexyl)-3-(2-methyl-2-phenyl-propyl)-ureido]-thiazol-5-ylsulfanyl}-acetic acid methyl ester (350 mg).
