trans-4-[2-(4-Furo[3,2-c]pyridin-4-yl-piperazin-1-yl)-ethyl]-cyclohexylamine trihydrochloride (intermediate A) (150 mg, 0.34 mmol) was dissolved in CH2Cl2 (1.5 ml) and the solution was cooled to 0° C. Et3N (139 mg, 1.37 mmol) and methanesulfonyl chloride (78 mg, 0.68 mmol) were added and the reaction mixture was stirred over night at room temperature. H2O was added and the product was extracted with CH2Cl2. The organic layer was dried (Na2SO4) and the solvent was evaporated. Purification by flash chromatography over silica gel (CH2Cl2/MeOH/25% NH3 aq 140:10:1) yielded the title compound as a white solid (78 mg, 56%), MS (ISP) m/z=407.2 [(M+H)+].
