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 (75 mg, 0.19 mmol), DMF (0.15 mL), ethanol (0.85 mL), 1M Na2S2O4 (3 eq, 0.57 mmol, 0.57 mL) and 6-methoxy-3-pyridinecarboxaldehyde (1.1 eq, 0.21 mmol, 29 mg). After 6 h, concentration in vacuo and purification by preparative tlc (CH2Cl2-MeOH, 9:1) gave the product (31 mg, 34%) as a colourless solid; δH (500 MHz, DMSO-d6) 2.63 (br s, 4H, piperazine N(CH2)2), 3.62 (s, 2H, NCH2Ar), 3.68 (br s, 4H, piperazine N(CH2)2), 3.95 (s, 3H, OCH3), 7.00 (d, J=8.7 Hz, 1H, methoxypyridine H-5), 7.40 (dd, J=7.8, 4.8 Hz, 1H, pyridine H-5), 7.79 (d, br, J=7.8 Hz, 1H, pyridine H-4), 8.24 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.43 (dd, J=8.7, 2.3 Hz, 1H, methoxypyridine H-4), 8.50 (d, br, J=3.5 Hz, 1H, pyridine H-6), 8.57 (s, 1H, pyridine H-2), 8.96 (d, J=2.3 Hz, 1H, methoxypyridine H-2), 13.53 (s, br, 1H, imidazo[4,5-b]pyridine NH);
