반응 단계
To a mixture of 5-bromo-4-(4-((1-methyl-1H-imidazol-5-yl)methyl)piperazin-1-yl)-3-nitropyridin-2-amine (0.050 g, 0.126 mmol, 1 eq), EtOH (2.2 mL), and DMF (0.3 mL), 4-(1H-pyrazol-1-ylmethyl)-benzaldehyde (0.026 g, 0.14 mmol, 1.1 eq) was added followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.38 mL, 0.38 mmol). The reaction mixture was heated at 85° C. for 24 h, then allowed to cool to room temperature and diluted with DCM and a few drops of aqueous NH3 until complete dissolution was observed. This solution was deposited on two preparative silica TLC plates and eluted with DCM/MeOH (v/v; 92:8). The title compound was obtained as a solid after trituration with diethyl ether (0.008 g, 12%); 1H-NMR (500 Mz, DMSO-d6): 2.55-2.62 (m, 4H, piperazine N(CH2)2), 3.53 (s, 2H, NCH2), 3.61-3.67 (m, 4H, piperazine N(CH2)2), 3.68 (s, 3H, imidazole Me), 5.41 (s, 2H, NCH2), 6.30 (t, J=2.0 Hz, 1H, pyrazole H-4), 6.81 (s, 1H, imidazole H-4), 7.34 (d, J=8.0 Hz, 2H, ArH, C6H4), 7.49 (d, J=1.5 Hz, 1H, pyrazole H-3), 7.58 (s, 1H, imidazole 2-H), 7.85 (d, J=2.0 Hz, 1H, pyrazole H-3), 8.13 (d, J=8.5 Hz, 2H, ArH, C6H4), 8.23 (s, 1H, imidazo[4,5-b]pyridine 5-H); LC (Method B)-MS (ESI, m/z) 2.71 min—532/534 [(M+H)+], Br isotopic pattern]. ESI-HRMS: Found: 532.1567, calculated for C25H27BrN9 (M+H)+: 532.1573.
