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 (50 mg, 0.13 mmol), DMF (0.3 mL), ethanol (1.2 mL), 1M Na2S2O4 (3 eq, 0.38 mmol, 0.38 mL) and tert-butyl 4-(4-formylbenzyl)piperazine-1-carboxylate (1.1 eq, 0.14 mmol, 45 mg). After 6 h, concentration in vacuo and purification by preparative tlc (CH2Cl2-MeOH, 95:5) gave the product (22 mg, 27%) as a pale yellow solid; δH (500 MHz, DMSO-d6) 1.39 (s, 9H, C(CH3)3), 2.34 (t, J=5.0 Hz, 4H, piperazine N(CH2)2), 2.62 (s, br, 4H, piperazine N(CH2)2), 3.32 (s, br, 4H, piperazine N(CH2)2), 3.55 (s, 2H, CH2), 3.62 (s, 2H, CH2), 3.67 (t, J=4.8 Hz, 4H, piperazine N(CH2)2), 7.39 (dd, J=7.8, 4.8 Hz, 1H, pyridine H-5), 7.46 (d, J=8.1 Hz, 2H, phenyl H-3 & H-5), 7.78 (d, br, J=8.0 Hz, 1H, pyridine H-4), 8.14 (d, J=8.1 Hz, 2H, phenyl H-2 & H-6), 8.23 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.50 (dd, J=4.8, 1.6 Hz, 1H, pyridine H-6), 8.56 (d, J=1.7 Hz, 1H, pyridine H-2), 13.46 (s, br, 1H, imidazo[4,5-b]pyridine NH);
