Sodium Dithionite → US9447092, Comparator 1, Example 56

Beteiligte Stoffe

Reaktionsschritte

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 1-methyl-1H-pyrazole-4-carboxaldehyde (1.1 eq, 0.21 mmol, 23 mg). After 6 h, concentration in vacuo and preparation by preparative tlc (CH2Cl2-MeOH, 9:1) gave the product (23 mg, 24%) as a colourless solid; 1H-NMR (500 MHz, DMSO-d6) 2.60 (br s, 4H, piperazine N(CH2)2), 3.60 (t, J=4.5 Hz, 4H, piperazine N(CH2)2), 3.61 (s, 2H, CH2), 3.93 (s, 3H, NCH3), 7.40 (dd, J=7.6, 4.8 Hz, 1H, pyridine H-5), 7.78 (d, br, J=7.7 Hz, 1H, pyridine H-4), 8.06 (s, 1H, pyrazole H-2 or H-4), 8.19 (s, 1H, imidazo[4,5-b]pyridine H-5), 8.35 (s, 1H, pyrazole H-2 or H-4), 8.50 (d, br, J=4.7 Hz, 1H, pyridine H-6), 8.57 (s, br, 1H, pyridine H-2), 13.21 (br s, 1H, imidazo[4,5-b]pyridine NH);

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