A round bottom flask was charged with 4-(3-(4-fluoro-phenyl)-3-oxopropyl)-1-tert-butoxycarbonyl-piperidine (614 mg, 1.83 mmol, from Step C), LiI, (294 mg, 2.2 mmol), KCN (358 mg, 5.5 mmol), and K2CO3 (3 grams, 22 mmol) in 30 mL DMSO. The mixture was heated to 135° C. for 72 h. The solution was cooled to room temperature and di-tert-butyl dicarbonate (500 mg, 2.3 mmol) was added. After 1 h the mixture was diluted with 100 mL EtOAc and the organic phase washed with water (50 mL) and sat'd NaCl (2×50 mL), then dried over Na2SO4 and concentrated. Flash chromatography (3/1 hexane/EtOAc eluant) afforded 75 mg (12%) of the title compound.
