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-methyl-N-phenyl-acetamide (0.037 g, 0.09 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 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 first with ethyl acetate/dichloromethane (v/v; 1:1), and then 1-2% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained after trituration with diethyl ether as a pale yellow solid (0.008 g, 18%); 1H-NMR (500 Mz, DMSO-d6) 2.58 (br s, 4H, piperazine N(CH2)2), 3.00 (s, 6H, N(CH3)2), 3.21 (s, 3H, NCH3), 3.61 (br s, 4H, piperazine N(CH2)2), 6.82 (d, J=9.87 Hz, 2H, 3,5-C6H4—NMe2 or 2,6-C6H4—NMe2), 7.30-7.50 (m, 5H, N-Ph), 8.00 (m, 3H, 3,5-C6H4—NMe2 or 2,6-C6H4—NMe2 and imidazo[4,5-b]pyridine 5-H); 13.09 (s, 1H, imidazo[4,5-b]pyridine N—H); LC-MS (ESI, m/z) 5.10 min—504, 506 [(M+H)+, Cl isotopic pattern]; ESI-HRMS Found: 504.2278, calculated for C27H31N7ClO (M+H)+: 504.2279.

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