Sodium triacetoxyborohydride (118 mg, 0.56 mmol) was added to a solution of 4-(5-amino-benzooxazol-2-yl)-1,4-diaza-bicyclo[3.2.2]nonane (52 mg, 0.20 mmol, prepared as in Example 39) and benzaldehyde (21 μL, 0.204 mmol) in 1,2-dichloroethane. The resulting mixture was allowed to stir at RT for a period of 3 h. at which time 2 mL of 1 N NaOH solution was added. The aqueous layer was extracted with CDCl3 (3×) and the combined organic layers were washed with water and brine and then dried (Na2SO4), filtered and concentrated. The crude residue was purified by chromatography (Biotage, 25M) eluting with 6% MeOH in CDCl3 containing 1 mL of NH4OH per L of eluent to give 37 mg of the title compound as an oil: 1H NMR CDCl3, 400 MHz) δ 7.37-7.29 (m, 3H), 7.25-7.22 (m, 2H), 7.00 (d, 1H, J=8.7 Hz), 6.64 (d, 1H, J=2.1 Hz), 6.27 (dd, 1H, J=8.7, 2.1 Hz), 4.47-4.45 (m, 1H), 4.30 (s, 2H), 3.87 (t, 2H, J=5.8 Hz), 3.16-3.09 (m, 4H), 3.01-2.96 (m, 2H), 2.15-2.08 (m, 2H), 1.81-1.73 (m, 2H): 13C NMR (CDCl3, 100 MHz) δ 146.0, 145.1, 142.0, 139.8, 128.8, 127.7, 127.3, 108.8, 106.0, 100.6, 57.3, 50.1, 49.4, 46.5, 44.1, 27.0; MS (Cl) m/z 349.2 (M+1).
