A solution of tert-butyl 5-aminomethyl-3,6-dihydro-2H-pyridine-1-carbamate (0.7 g, 3.3 mmol) and 1,4-benzodioxane-6-carbaldehyde (0.54 g, 3.3 mmol) in THF (2 ml) and DCE (4 ml) was stirred at room temperature for 1 hour. Sodium triacetoxyborohydride (0.770 g, 3.81 mmol) was then added thereto. The reaction mixture was stirred at room temperature for 5 hours and filtered through Hydromatrix (wetted with saturated NaHCO3 solution) and the filtrate was concentrated. The residue was purified by chromatography on silica gel (EtOAc/hex 2/1 and then EtOAc/MeOH 9/1).
