2,6-Diaza-spiro[3.3]heptane-2-carboxylic acid 2,4-dichloro-benzylamide (245 mg, 416 μmol) and triethylamine (200 mg, 198 mmol) were dissolved in dichloromethane (5 mL) followed by benzoyl chloride (70 mg, 499 μmol) and the reaction mixture was stirred for 1 h at ambient temperature. The crude reaction mixture was concentrated under reduced pressure. The residue was purified by chromatography (SiO2; methanol:dichloromethane 0:1 to 1:19) to give the title compound (106 mg, 63%) as a colorless solid. MS (EI) m/e: 404.1 (M+H)+.
