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-chloro-3-nitro-4-(4-(pyrimidin-5-ylmethyl)piperazin-1-yl)pyridin-2-amine (25 mg, 0.071 mmol), DMF (0.15 mL), ethanol (0.85 mL), 1M Na2S2O4 (3 eq, 0.21 mmol, 0.21 mL) and tert-butyl 4-(4-formylbenzyl)piperazine-1-carboxylate (1.2 eq, 0.085 mmol, 28 mg). After 6 h, concentration in vacuo and purification by preparative tlc (CH2Cl2-MeOH, 95:5) gave the product (19 mg, 44%) as a colourless solid; δH (500 MHz, DMSO-d6) 1.39 (s, 9H, C(CH3)3), 2.34 (t, J=4.9 Hz, 4H, piperazine N(CH2)2), 2.64 (t, J=4.4 Hz, 4H, piperazine N(CH2)2), 3.32 (s, br, 4H, piperazine N(CH2)2), 3.55 (s, 2H, NCH2), 3.65 (s, 2H, NCH2), 3.71 (s, br, 4H, piperazine N(CH2)2), 7.46 (d, J=8.2 Hz, 2H, phenyl H-3 & H-5), 8.11 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.13 (d, J=8.1 Hz, 2H, phenyl H-2 & H-6), 8.80 (s, 2H, pyrimidine H-4 & H-6), 9.12 (s, 1H, pyrimidine H-2), 13.34 (s, br, 1H, imidazo[4,5-b]pyridine NH);
