4-(Dimethylamino)Benzaldehyde → 4-(6-Bromo-7-(4-(pyridin-4-ylmethyl)piperazin-1-yl)-3H-imidazo[4,5-b]pyridin-2-yl)-N,N-dimethylaniline

Participants

Reaction Conditions

Reaction Steps

To a mixture of 5-bromo-3-nitro-4-(4-(pyridin-4-ylmethyl)piperazin-1-yl)pyridin-2-amine (0.043 g, 0.11 mmol), ethanol (4 ml), and 4-dimethylaminobenzaldehyde (0.021 g, 0.14 mmol) was added a freshly prepared aqueous solution of Na2S2O4 (1M; 0.44 ml, 0.44 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 1 to 4% methanol in ethyl acetate/dichloromethane (v/v; 1:1). The title compound was obtained as a yellow solid after trituration with diethyl ether (0.013 g, 24%); 1H-NMR (500 MHz, DMSO-d6) 2.63 (br s, 4H, piperazine N(CH2)2), 3.00 (s, 6H, N(CH3)2), 3.66 (br s, 4H, piperazine N(CH2)2), 3.62 (s, 2H, NCH2), 6.81 (d, J=9.04 Hz, 2H) and 8.01 (d, J=8.81 Hz, 2H) (3,5-C6H4NMe2 and 2,6-C6H4—NMe2), 7.40 (d, J=5.86 Hz, 2H), and 8.54 (d, J=4.42 Hz, 2H) (pyrid-4-yl protons), 8.15 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.14 (s, 1H, imidazo[4,5-b]pyridine N—H);

Provenance & Evidence