4-(Dimethylamino)Benzaldehyde → (4-(6-Chloro-2-(4-(dimethylamino)phenyl)-3H-imidazo[4,5-b]pyridin-7-yl)piperazin-1-yl)(4-methoxyphenyl)methanone

Participants

Reaction Conditions

Reaction Steps

To a mixture of (4-(2-amino-5-chloro-3-nitropyridin-4-yl)piperazin-1-yl)(4-methoxyphenyl)methanone (0.034 g, 0.09 mmol), ethanol (3 ml), and 4-dimethylamino-benzaldehyde (0.018 g, 0.12 mmol) was added a freshly prepared aqueous solution of Na2S2O4 (1M; 0.35 ml, 0.35 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 first with ethyl acetate/dichloromethane (v/v; 6:4) and then 2% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was isolated as a pale yellow solid after trituration with diethyl ether (0.008 g, 20%); 1H-NMR (500 Mz, DMSO-d6) 3.00 (s, 6H, N(CH3)2), 3.68 (br s), and 3.72 (br s) (8H, piperazine N(CH2)2), 3.81 (s, 3H, OCH3), 6.82 (d, J=8.93 Hz, 2H), and 8.01 (d, J=8.85 Hz, 2H) (2,6-C6H4—NMe2 and 3,5-C6H4—NMe2), 7.02 (d, J=8.64 Hz, 2H) and 7.45 (d, J=8.62 Hz, 2H) (2,6-C6H4—OMe and 3,5-C6H4—OMe), 8.06 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.15 (s, 1H, imidazo[4,5-b]pyridine N—H);

Provenance & Evidence