To a mixture of 4-(1-bromo-1-phenyl-methylene)-piperidine-1-carboxylic acid tert-butyl ester (0.115 g, 0.33 mmol) and 3,5-difluorophenylboronic acid (0.052 g 0.33 mmol) in DME (3 mL) was added 2M sodium carbonate (0.65 mL, 1.30 mmol). The reaction vessel was then flushed with Ar for 10 minutes, Pd2 dba3 (0.015 g, 0.016 mmol) was added, the vessel was sealed and the mixture was heated at 90° C. for 16 h. The cooled mixture was filtered (0.45 μm syringe filter) and the filtrate was evaporated. The residue was purified by preparative HPLC to give the title compound (0.080 g, 64%) as a white solid:
