3-Benzyl-9-oxa-3,7-diaza-bicyclo[3.3.1]nonane (0.18 g, 0.82 mmol; see WO 01/28992) and toluene-4-sulfonic acid 2-{1-[2-(4-cyanophenoxy)ethyl]-ureido}ethyl ester (0.50 g, 1.24 mmol; see Preparation D above) were mixed in dry acetonitrile (15 mL) and stirred at 60° C. overnight. DCM (10 mL) was added, together with 0.5 g of PS—NCO (polymer-supported isocyanate). The mixture was stirred for 2 h, then filtered and evaporated. The crude product was put on a SCX-II (cation exchanger)-plug, which plug was then eluted with DCM:MeOH (NH3-saturated), 80:20. The product was further purified on a Horizon prep. column (40 g, A: DCM(1% MeOH), B: DCM/MeOH(NH3-sat.), 80:20. Gradient 0-30% B over 1080 mL). The product was then further purified by prep. HPLC and finally extracted with DCM/Na2CO3 (aq.) to give 193 mg (51.9%) of the title compound.
