反应详情

温度

80 °C

To a mixture of 2-[4-(2-amino-5-chloro-3-nitro-pyridin-4-yl)-piperazin-1-yl]-N-thiazol-2-yl-acetamide (0.028 g, 0.07 mmol) and EtOH (3.0 ml) was added 4-pyrazol-1-ylmethyl-benzaldehyde (0.017 g, 0.09 mmol) followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.30 ml, 0.30 mmol). The reaction mixture was stirred at 80° C. for 20 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 a gradient of methanol (0 to 5%) in ethyl acetate/dichloromethane (v:v; 1:1) afforded a pale yellow solid. The title compound was obtained as a white solid after trituration with diethyl ether (0.006 g, 16%); 1H-NMR (500 MHz, DMSO-d6) 2.77 (br s, 4H, piperazine N(CH2)2), 3.40 (s, 2H, NCH2CON), 3.73 (br s, 4H, piperazine N(CH2)2), 5.41 (s, 2H, C6H4CH2N), 6.30 (t, J=1.9 Hz, 1H, pyrazole 4-H), 7.23 (d, J=3.5 Hz, 1H, thiazole H), 7.35 (d, J=7.6 Hz, 2H) and 8.14 (d, J=8.3 Hz, 2H) (3,5-C6H4— and 2,6-C6H4—), 7.49 (d, 2H, thiazole-H, and pyrazole-H), 7.86 (d, J=1.84 Hz, 1H, pyrazole-H), 8.11 (s, 1H, imidazo[4,5-b]pyridine 5-H), 11.89 (s, 1H, CONH), 13.48 (br s, 1H, imidazo[4,5-b]pyridine N—H); LC (Method B)-MS (ESI, m/z): Rt=3.89 min—534, 536 [(M+H)+, Cl isotopic pattern]. ESI-HRMS: Found: 534.1595, calculated for C25H25ClN9OS (M+H)+: 534.1591.

1. temperatureto cool to room temperature
2. concentrationconcentrated in vacuo
3. customThe resulting residue was absorbed on silica
4. washElution with a gradient of methanol (0 to 5%) in ethyl acetate/dichloromethane (v:v; 1:1)
5. customafforded a pale yellow solid