To a solution of spiro[3.5]nonan-7-ylmethanol (0.58 g, 3.76 mmol) in anhydrous dimethyl sulfoxide (20 mL) was added potassium t-butoxide (1.05 g, 9.35 mmol) at ambient temperature. After stirring at ambient temperature for 30 minutes, N-(azetidin-1-ylsulfonyl)-5-chloro-2,4-difluorobenzamide (1.17 g, 3.76 mmol) was added to the reaction mixture; stirring was continued at ambient temperature for 2 hours. The mixture was cooled to 0° C. and quenched with 5% aqueous hydrochloride acid (10 mL) followed by extraction with ethyl acetate (100 mL). The organic layer was washed with water (2×40 mL) and brine, dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated in vacuo, the crude product was purified by silica gel column chromatography using 10-40% ethyl acetate (containing 0.2% acetic acid) in hexanes to afford the title compound as a colorless solid (0.60 g, 36%): 1H NMR (300 MHz, CDCl3) δ 8.60 (d, J=15.6 Hz, 1H), 8.10 (d, J=8.4 Hz, 1H), 6.66 (d, J=13.8 Hz, 1H), 4.23 (t, J=7.8 Hz, 4H), 3.82 (d, J=6.3 Hz, 2H), 2.32-2.20 (m, 2H), 1.88-1.66 (m, 11H), 1.35-1.24 (m, 2H), 1.18-1.05 (m, 2H); MS (ES+) m/z 445.1, 447.1 (M+1), MS (ES−) m/z 443.2, 445.2 (M−1).
