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 benzaldehyde (0.015 g, 0.14 mmol) was added a freshly prepared aqueous solution of sodium dithionite (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 with 70% dichloromethane in ethyl acetate and then 2% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained as an off white solid after trituration with diethyl ether (0.011 g, 24%); 1H-NMR (500 MHz, DMSO-d6) 2.73 (br s, 4H, piperazine N(CH2)2), 3.40 (s, 2H, CH2CO), 3.75 (br s, 4H, piperazine N(CH2)2), 7.23 (d, J=3.46 Hz, 1H) and 7.49 (d, J=3.46 Hz, 1H) (thiazole 4-H, 5-H), 8.12 (s, 1H, imidazo[4,5-b]pyridine 5-H), 7.60 (m, 3H) and 8.19 (d, J=7.00 Hz, 2H) (ArH), 11.92 (s, 1H, CONH), 13.49 (s, 1H, imidazo[4,5-b]pyridine N—H); LC-MS (ESI, m/z) Rt=6.16 min—454, 456 [(M+H)+, Cl isotopic pattern]. ESI-HRMS: Found: 454.1230, calculated for C21H21N7OSCl (M+H)+: 454.1217.

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 70% dichloromethane in ethyl acetate