Sodium Dithionite → 2-(4-(6-Chloro-2-(4-methoxyphenyl)-3H-imidazo[4,5-b]pyridin-7-yl)piperazin-1-yl)-N-(thiazol-2-yl)acetamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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 p-methoxybenzaldehyde (0.019 g, 0.14 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 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 50% dichloromethane in ethyl acetate and then 2.5% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained as a pale yellow solid after trituration with diethyl ether (0.012 g, 25%); 1H-NMR (500 MHz, DMSO-d6) 2.76 (br s, 4H, piperazine N(CH2)2), 3.40 (s, 2H, NCH2CO), 3.72 (br s, 4H, piperazine N(CH2)2), 3.83 (s, 3H, OCH3), 7.10 (d, J=8.79 Hz, 2H, 3,5-ArH or 2,6-ArH), 7.24 (d, J=3.51 Hz, 1H) and 7.50 (d, J=3.55 Hz, 1H) (thiazole 4-H, 5-H), 8.09 (s, 1H, imidazo[4,5-b]pyridine 5-H), 8.13 (d, 2H, J=8.76 Hz, 3,5-ArH or 2,6-ArH); 11.95 (s, 1H, CONH), 13.72 (s, 1H, imidazo[4,5-b]pyridine N—H);

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