反应详情

温度

70 °C

To a mixture of 5-chloro-3-nitro-4-(4-(1-phenylethyl)piperazin-1-yl)pyridin-2-amine (0.038 g, 0.10 mmol), ethanol (3 ml), and 4-dimethylamino-benzaldehyde (0.023 g, 0.15 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 6 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 2.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The obtained yellow solid was suspended in dichloromethane (2 ml), and then a solution of HCl in methanol (1.25 M; 0.8 ml) was added. The mixture was stirred for approximately 1 min, and then diethyl ether was added. The yellow precipitate was collected by filtration, washed with ether to afford the title compound as a hydrochloride salt. (0.013 g); 1H-NMR (500 Mz, CD3OD) 1.90 (d, J=5.43 Hz, 3H, CHCH3), 3.43 (m), 3.96 (m), 4.12 (m) (8H, piperazine N(CH2)2), 3.21 (s, 6H, N(CH3)2), 4.65 (m, 1H, NCHCH3), 7.14 (d, J=7.30 Hz, 2H) and 8.14 (d, J=7.32 Hz, 2H) (3,5-C6H4—NMe2 and 2,6-C6H4—NMe2) 7.55 (m, 3H) and 7.66 (m, 2H) (ArH), 8.41 (s, 1H, imidazo[4,5-b]pyridine 5-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 2.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1)
5. additiona solution of HCl in methanol (1.25 M; 0.8 ml) was added
6. additiondiethyl ether was added
7. filtrationThe yellow precipitate was collected by filtration
8. washwashed with ether