反应详情

温度

80 °C

To a mixture of 5-bromo-4-[4-(5-methyl-isoxazol-3-ylmethyl)-piperazin-1-yl]-3-nitro-pyridin-2-ylamine (0.040 g, 0.10 mmol) and EtOH (3 ml) was added 3-methoxybenzaldehyde (0.022 g, 0.16 mmol) with the aid of EtOH (1 ml), 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 20 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 ethyl acetate/dichloromethane (v:v; 3:7) and then a gradient of methanol (0 to 2%) in ethyl acetate/dichloromethane (v:v; 1:1) afforded a yellowish solid. The title compound was obtained as a white solid after trituration with diethyl ether (0.010 g, 21%); 1H-NMR (500 MHz, DMSO-d6) 2.40 (s, 3H, isoxazole 5-CH3), 2.64 (br s, 4H, piperazine N(CH2)2), 3.60 (s, 2H, NCH2 isoxazole), 3.67 (br s, 4H, piperazine N(CH2)2), 3.85 (s, 3H, OCH3), 6.25 (s, 1H, isoxazole 4-H), 7.09 (dd, J=1.9, 8.3 Hz, 1H, PhH), 7.45 (t, J=8.3 Hz, 1H, Ph 5-H), 7.76 (s, 1H, Ph 2-H), 7.79 (d, J=8.3 Hz, PhH), 8.24 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.50 (br s, 1H, imidazo[4,5-b]pyridine N—H);

1. temperatureto cool to room temperature
2. concentrationconcentrated in vacuo
3. customThe resulting residue was absorbed on silica
4. washElution with ethyl acetate/dichloromethane (v:v; 3:7)
5. customa gradient of methanol (0 to 2%) in ethyl acetate/dichloromethane (v:v; 1:1) afforded a yellowish solid