A mixture of racemic trans-(3-methoxy-cyclopentyl)-acetic acid methyl ester [WO 2009/019174] (70 mg, 0.41 mmol) and KOSiMe3 (88 mg, 0.69 mmol) in CH2Cl2 (1.5 ml) was stirred at room temperature over night. The solvent was evaporated and DMF (1.5 ml) was added followed by trans-4-[2-(4-furo[3,2-c]pyridin-4-yl-piperazin-1-yl)-ethyl]-cyclohexylamine trihydrochloride (intermediate A) (150 mg, 0.34 mmol), DIPEA (177 mg, 1.37 mmol) and TBTU (143 mg, 0.44 mmol). After stirring 4 h at room temperature, sat. aq. NaHCO3 sol. was added and the product was extracted with CH2Cl2. The organic layer was dried (Na2SO4), the solvent was evaporated and the crude product was purified by flash chromatography on silica gel (CH2Cl2/MeOH/25% NH3 aq 140:10:1) to yield the title compound as a white solid (125 mg, 78%), MS (ISP) m/z=469.3 [(M+H)+].
