反应详情

温度

70 °C

To a mixture of 2-[4-(2-Amino-5-chloro-3-nitro-pyridin-4-yl)-piperazin-1-yl]-N-thiazol-2-yl-acetamide (0.040 g, 0.10 mmol), ethanol (3 ml), and 4-dimethylamino-benzaldehyde (0.019 g, 0.13 mmol) was added a freshly prepared aqueous solution of Na2S2O4 (1M; 0.4 ml, 0.4 mmol). The reaction mixture was heated at 70° C. for 3.5 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 ethyl acetate/dichloromethane (v/v; 1:1), 1.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1) and finally 2% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained after trituration with diethyl ether as a pale yellow solid (0.005 g, 10%); 1H-NMR (250 Mz, DMSO-d6) 2.78 (m, 4H, piperazine N(CH2)2), 3.01 (s, 6H, N(CH3)2), 3.40 (s, 2H, NCH2CO), 3.72 (m, 4H, piperazine N(CH2)2), 6.83 (d, J=8.79 Hz, 2H, 3,5-ArH or 2,6-ArH), 7.25 (d, J=3.42 Hz, 1H) and 7.51 (d, J=3.53 Hz, 1H) (thiazole 4-H, 5-H), 8.03 (d, 3H, J=9.88 Hz, 3,5-ArH or 2,6-ArH, and imidazo[4,5-b]pyridine 5-H); 11.95 (s, 1H, CONH), 13.12 (s, 1H, imidazo[4,5-b]pyridine N—H); LC-MS (ESI, m/z) 6.17 min—497, 499 [(M+H)+, Cl isotopic pattern]; ESI-HRMS Found: 497.1652, calculated for C23H26N8ClOS (M+H)+: 497.1633.

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 ethyl acetate/dichloromethane (v/v; 1:1), 1.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1) and finally 2% methanol in ethyl acetate/dichloromethane (v/v; 1:1)