Ethanol → 2-(4-((1H-Pyrazol-1-yl)methyl)phenyl)-6-bromo-7-(4-(4-chlorobenzyl)piperazin-1-yl)-3H-imidazo[4,5-b]pyridine

Participants

Reaction Conditions

Reaction Steps

To a mixture of 5-bromo-4-[4-(4-chloro-benzyl)-piperazin-1-yl]-3-nitro-pyridin-2-ylamine (0.043 g, 0.10 mmol) and EtOH (4.0 ml) was added 4-pyrazol-1-ylmethyl-benzaldehyde (0.024 g, 0.13 mmol) followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.40 ml, 0.40 mmol). The reaction mixture was stirred at 80° C. for 22 h, then allowed to cool to room temperature and concentrated in vacuo. The resulting residue was absorbed on silica, and the free-running powder was placed on a 10 g isolute silica column. Elution with a gradient of methanol (0 to 2%) in ethyl acetate/dichloromethane (v:v; 1:1) afforded a yellow solid. The title compound was obtained as a white solid after trituration with diethyl ether (0.023 g, 40%); 1H-NMR (500 MHz, DMSO-d6) 2.66 (br s, 4H, piperazine N(CH2)2), 3.56 (s, 2H, NCH2C6H4Cl), 3.66 (br s, 4H, piperazine N(CH2)2), 5.42 (s, 2H, C6H4CH2N), 6.30 (t, J=1.9 Hz, 1H, pyrazole 4-H), 7.35 (d, J=7.6 Hz, 2H) and 8.14 (d, J=8.3 Hz, 2H) (3,5-C6H4CH2N and 2,6-C6H4CH2N), 7.40 (m, 4H, C6H4Cl), 7.49 (d, J=1.5 Hz, 1H, pyrazole-H), 7.86 (d, J=1.8 Hz, 1H, pyrazole-H), 8.23 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.54 (br s, imidazo[4,5-b]pyridine N—H);

Provenance & Evidence