反应详情

温度

70 °C

To a mixture of 5-bromo-4-[4-(5-methyl-isoxazol-3-ylmethyl)-piperazin-1-yl]-3-nitro-pyridin-2-ylamine (0.044 g, 0.11 mmol) and EtOH (3 ml) was added 4-methoxybenzaldehyde (0.023 g, 0.17 mmol) with the aid of EtOH (1 ml), followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.44 ml, 0.44 mmol). The reaction mixture was stirred at 70° C. for 18 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 2.5% methanol in ethyl acetate/dichloromethane (v:v; 1:1) afforded a yellow solid. The title compound was obtained as a pale yellow solid after trituration with diethyl ether (0.023 g, 43%); 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), 3.65 (br s, 4H, piperazine N(CH2)2), 3.84 (s, 3H, OCH3), 6.25 (s, 1H, isoxazole 4-H), 7.10 (d, J=8.9 Hz, 2H) and 8.13 (d, J=8.8 Hz, 2H) (3,5-C6H4 OMe and 2,6-C6H4OMe), 8.20 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.35 (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. custom2.5% methanol in ethyl acetate/dichloromethane (v:v; 1:1) afforded a yellow solid