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

HRID 416742Notes

Reaction equation

[Br:1][C:2]1[C:3]([N:12]2[CH2:17][CH2:16][N:15]([CH2:18][C:19]3[CH:24]=[CH:23][N:22]=[CH:21][CH:20]=3)[CH2:14][CH2:13]2)=[C:4]([N+:9]([O-])=O)[C:5]([NH2:8])=[N:6][CH:7]=1.[CH3:25][N:26]([CH3:35])[C:27]1[CH:34]=[CH:33][C:30]([CH:31]=O)=[CH:29][CH:28]=1.[O-]S(S([O-])=O)=O.[Na+].[Na+]>C(O)C>[Br:1][C:2]1[C:3]([N:12]2[CH2:17][CH2:16][N:15]([CH2:18][C:19]3[CH:24]=[CH:23][N:22]=[CH:21][CH:20]=3)[CH2:14][CH2:13]2)=[C:4]2[N:9]=[C:31]([C:30]3[CH:33]=[CH:34][C:27]([N:26]([CH3:35])[CH3:25])=[CH:28][CH:29]=3)[NH:8][C:5]2=[N:6][CH:7]=1

Participants

Conditions

Temperature: 70 °C

Procedure

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);

Workup

temperatureto cool to room temperature
customthe solvents were removed in vacuo
customThe residue was absorbed on silica gel
washwas eluted with 1 to 4% methanol in ethyl acetate/dichloromethane (v/v; 1:1)

Sources & evidence

ORD record: ord-80ed42876c924864a9d88e9201f21f1a
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08088761B2

Reaction notes

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