A mixture of N-(1-azabicyclo[2.2.2]oct-3-yl)-2-(4-trimethylsilylethynylphenyl)benzoxazole-4-carboxamide (20 mg, 0.045 mmol), potassium carbonate (20 mg, 0.14 mmol) and methanol (1 mL) was stirred at room temperature for 2 h, and then was diluted with ethyl acetate, washed with water and brine, dried (Na2SO4), filtered and concentrated. The crude material was purified by column chromatography (silica gel, 90:10:1 ethyl acetate/methanol/concentrated ammonium hydroxide) to afford N-(1-azabicyclo[2.2.2]oct-3-yl)-2-(4-ethynylphenyl)benzoxazole-4-carboxamide (14 mg, 84%) as a white solid: 1H NMR (500 MHz, CDCl3) δ 9.49 (d, J=7.0 Hz, 1H), 8.22-8.18 (m, 3H), 7.73 (dd, J=8.0, 1.0 Hz, 1H), 7.68 (d, J=8.5 Hz, 2H), 7.48 (t, J=8.0 Hz, 1H), 4.35-4.31 (m, 1H), 3.53 (ddd, J=14.0, 9.5, 2.0 Hz, 1H), 3.30 (s, 1H), 3.15-2.82 (m, 5H), 2.20-2.03 (m, 2H), 1.80-1.62 (m, 3H); MS (ESI+) m/z 372 (M+H); HPLC>99% (AUC), tR=12.77 min.
