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 (0.85 mL), ethanol (0.15 mL), 1M Na2S2O4 (3 eq, 0.57 mmol, 0.57 mL) and 3-[(4-methylpiperazin-1-yl)methyl]benzaldehyde (1.1 eq, 0.21 mmol, 46 mg). After 6 h, concentration in vacuo and preparation by preparative tlc (CH2Cl2-MeOH, 9:1) gave the product (19 mg, 18%) as a colourless solid; 1H-NMR (500 MHz, DMSO-d6) 2.15 (s, 3H, NCH3), 2.50 (hidden by DMSO peak, 4H, piperazine N(CH2)2), 2.64 (br, 4H, piperazine N(CH2)2), 3.30 (hidden by watert-in-DMSO peak, 4H, piperazine N(CH2)2), 3.56 (s, 2H, CH2), 3.63 (s, 2H, CH2), 3.68 (t, J=4.8 Hz, 4H, piperazine N(CH2)2), 7.40 (dd, J=7.8, 4.8 Hz, 1H, pyridine H-5), 7.43 (d, J=7.8 Hz, 1H, phenyl H-4 or H-6), 7.50 (t, J=7.8 Hz, 1H, phenyl H-5), 7.79 (d, br, J=7.7 Hz, 1H, pyridine H-4), 8.07 (d, br, J=8.5 Hz, 1H, phenyl H-4 or H-6), 8.14 (s, br, 1H, phenyl H-2), 8.25 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.50 (dd, J=4.8, 1.5 Hz, 1H, pyridine H-6), 8.57 (d, J=1.6 Hz, 1H, pyridine H-2), 13.52 (br s, 1H, imidazo[4,5-b]pyridine NH);
