NaBH(OAc)3 (0.014 mol) was added to a mixture of 2-amino-ethanesulfonic acid cyclohexyl-methyl-amide (0.0091 mol) and 5-benzoyl-2-nitro-benzaldehyde (0.0091 mol) in DCE (150 mL). The reaction mixture was then stirred overnight at room temperature and then washed with saturated NaHCO3 solution. The organic layer was separated, dried (MgSO4), and filtered, and the solvent was evaporated. The residue was purified by column chromatography (eluent: 100% CH2Cl2). The purest product fractions were collected and the solvent was evaporated to yield the title compound as a residue.
