To a solution of tert-butyl (6R,7R)-6-(aminomethyl)-7-(3,4-dichlorophenyl)-1,4-oxazepane-4-carboxylate (200 mg) in DMF (4 mL) were added potassium carbonate (110 mg) and methyl 2-chloronicotinate (137 mg) at room temperature, and the mixture was stirred at 100° C. for 48 hr. The reaction mixture was diluted with ethyl acetate. The diluted solution was washed with distilled water and brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel chromatography (hexane/ethyl acetate) to give the title compound (120 mg).
