To a solution of piperidine-4-carboxylic acid trifluoroacetate salt (0.20 g, 0.82 mmol) in methanol (10 mL), triethylamine (0.20 mL, 1.6 mmol) and N,N′-bis{[(2-methyl-2-propanyl)oxy]carbonyl}-1H-pyrazole-1-carboximidamide (0.30 g, 0.98 mmol) was added and the reaction mixture stirred at room temperature for 18 h. The solvent was evaporated under reduced pressure and the resulting residue dissolved in ethyl acetate and washed with brine. The organic layer was dried and concentrated to dryness to obtain the title compound (200 mg, 76%) as a white solid.
