反应详情

温度

70 °C

To a mixture of 5-bromo-4-(4-isobutylpiperazin-1-yl)-3-nitropyridin-2-amine (0.039 g, 0.11 mmol), ethanol (4 ml), and 4-dimethylaminobenzaldehyde (0.021 g, 0.14 mmol) was added a freshly prepared aqueous solution of Na2S2O4 (1M; 0.44 ml, 0.44 mmol). The reaction mixture was heated at 70° C. for 5 h, then allowed to cool to room temperature and the solvents were removed in vacuo. The residue was absorbed on silica gel and the free running powder was placed on a 10 g isolute silica column which was eluted with 1 to 2.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained as a yellow solid after trituration with diethyl ether (0.013 g, 26%); 1H-NMR (500 MHz, DMSO-d6) 0.91 (d, J=6.55 Hz, 6H, CH(CH3)2), 1.82 (m, 1H, CH(CH3)2), 2.12 (d, J=7.35 Hz, 2H, N—CH2), 2.56 (br s, 4H, piperazine N(CH2)2), 3.00 (s, 6H, N(CH3)2), 3.63 (br s, 4H, piperazine N(CH2)2), 6.82 (d, J=9.01 Hz, 2H) and 8.02 (d, J=8.87 Hz, 2H) (3,5-C6H4NMe2 and 2,6-C6H4—NMe2), 8.14 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.17 (s, 1H, imidazo[4,5-b]pyridine N—H);

1. temperatureto cool to room temperature
2. customthe solvents were removed in vacuo
3. customThe residue was absorbed on silica gel
4. washwas eluted with 1 to 2.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1)