A mixture of 2-amino-5-benzoylbenzaldehyde (0.007 mol) and cyclohexanecarboxylic acid (2-amino-ethyl)-amide (0.007 mol) in methanol was hydrogenated at 50° C. with 10% Pd/C (0.5 g) as a catalyst in the presence of thiophene solution (1 mL). After uptake of H2 gas (1 equiv.) the catalyst was filtered off and the solvent evaporated. The residue was purified by column chromatography over silica gel (Biotage column) (eluent:CH2Cl2:methanol gradient). The desired fractions were collected and the solvent evaporated to yield the title compound as a residue.
