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 (30 mg, 0.076 mmol), DMF (0.15 mL), ethanol (0.85 mL), 1M Na2S2O4 (3 eq, 0.23 mmol, 0.23 mL) and 4-(4-hydroxypiperidin-1-yl)benzaldehyde (1.2 eq, 0.091 mmol, 19 mg). After 6 h, concentration in vacuo and purification by preparative tlc (CH2Cl2-MeOH, 85:15) gave the product (11 mg, 26%) as a colourless solid; δH (500 MHz, DMSO-d6) 1.41-1.49 (m, 2H, 2× piperidine CHAHB), 1.81-1.84 (m, 2H, 2× piperidine CHAHB), 2.62 (s, br, 4H, piperazine N(CH2)2), 2.97-3.02 (m, 2H, 2× piperidine CHAHB), 3.62 (s, 2H, NCH2), 3.64 (t, J=4.7 Hz, 4H, piperazine N(CH2)2), 3.66-3.70 (m, 2H, 2× piperidine CHAHB), 4.68 (d, J=4.2 Hz, 1H, CHOH), 7.04 (d, J=9.0 Hz, 2H, phenyl H-2 & H-6), 7.39 (dd, J=7.6, 4.7 Hz, 1H, pyridine H-5), 7.78 (d, br, J=7.8 Hz, 1H, pyridine H-4), 7.99 (d, J=9.0 Hz, 2H, phenyl H-3 & H-5), 8.16 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.49 (d, br, J=4.5 Hz, 1H, pyridine H-6), 8.56 (s, br, 1H, pyridine H-2), 13.17 (s, br, 1H, imidazo[4,5-b]pyridine NH);
