To a solution of (R)-(1-(5,6-diaminopyridin-2-yl)piperidin-3-yl)(pyrrolidin-1-yl)methanone (0.4 g, 1.36 mmol) in ethanol was added ethyl 1-(2H-1,2,3-triazol-2-yl)cyclopropanecarbimidate (600 mg, crude), triethylamine (5 mL) and acetic acid (6 mL). The reaction mixture was heated to reflux for 12 h. The solvent was evaporated and the residue was dissolved in ethyl acetate. The solution was dried over sodium sulfate and concentrated. The crude material was purified via preparative TLC to afford the title compound (16 mg). MS (ES+) (M+H) 407.3; LCMS retention time 1.793 min (Method N1).
