Reaction Steps
This was prepared using the same procedure as for 4-(6-bromo-2-(4-(dimethylamino)phenyl)-3H-imidazo[4,5-b]pyridin-7-yl)-N-phenylpiperazine-1-carboxamide, but here using 5-bromo-3-nitro-4-(4-(pyridin-3-ylmethyl)piperazin-1-yl)pyridin-2-amine (20 mg, 0.051 mmol), DMF (0.15 mL), ethanol (0.85 mL), 1M Na2S2O4 (3 eq, 0.15 mmol, 0.15 mL) and 4-(1H-imidazol-1-ylmethyl)benzaldehyde (1.1 eq, 0.056 mmol, 11 mg). After 6 h, concentration in vacuo and purification by preparative tlc (CH2Cl2-MeOH, 9:1) gave the product (6 mg, 22%) as a colourless solid; δH (500 MHz, DMSO-d6) 2.62 (s, br, 4H, piperazine N(CH2)2), 3.61 (s, 2H, CH2), 5.28 (s, 2H, PhCH2), 6.93 (s, br, 1H, imidazole H-2), 7.21 (s, br, 1H, imidazole H-4 or H-5), 7.39 (dd, J=7.8, 4.8 Hz, 1H, pyridine H-5), 7.40 (d, J=8.1 Hz, 2H, phenyl H-2 & H-6), 7.78 (td, J=7.7, 1.5 Hz, 1H, pyridine H-4), 7.79 (s, br, 1H, imidazole H-4 or H-5), 8.15 (d, J=8.2 Hz, 2H, phenyl H-3 & H-5), 8.24 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.49 (dd, J=4.7, 1.4 Hz, 1H, pyridine H-6), 8.56 (d, J=1.5 Hz, 1H, pyridine H-2), 13.51 (s, br, 1H, imidazo[4,5-b]pyridine NH);
