Ethanol → 6-Bromo-7-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-(4-methoxy-phenyl)-3H-imidazo[4,5-b]pyridine

HRID 416801Notes

Reaction equation

HRID 416801 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][C:22]([Cl:25])=[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.CCO.[CH3:29][O:30][C:31]1[CH:38]=[CH:37][C:34]([CH:35]=O)=[CH:33][CH:32]=1.[O-]S(S([O-])=O)=O.[Na+].[Na+]>C(OCC)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][C:22]([Cl:25])=[CH:21][CH:20]=3)[CH2:14][CH2:13]2)=[C:4]2[N:9]=[C:35]([C:34]3[CH:37]=[CH:38][C:31]([O:30][CH3:29])=[CH:32][CH:33]=3)[NH:8][C:5]2=[N:6][CH:7]=1

Participants

6

Reactant 4

HCID 702Ethanol2×HCID 24489Sodium DithioniteHCID 312444-MethoxybenzaldehydeHCID 468687815-Bromo-4-(4-(4-chlorobenzyl)piperazin-1-yl)-3-nitropyridin-2-amine

Product 1

HCID 1784888666-Bromo-7-[4-(4-chloro-benzyl)-piperazin-1-yl]-2-(4-methoxy-phenyl)-3H-imidazo[4,5-b]pyridine

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
70 °C

Procedure

To a mixture of 5-bromo-4-[4-(4-chloro-benzyl)-piperazin-1-yl]-3-nitro-pyridin-2-ylamine (0.051 g, 0.12 mmol) and EtOH (3 ml) was added 4-methoxybenzaldehyde (0.026 g, 0.18 mmol) with the aid of EtOH (1 ml), followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.50 ml, 0.50 mmol). The reaction mixture was stirred at 70° C. for 18 h, then allowed to cool to room temperature and concentrated in vacuo. The residue was absorbed on silica gel, the free-running powder was placed on a 10 g isolute silica column and elution with a gradient of methanol (0 to 3%) in ethyl acetate/dichloromethane (v:v; 2:3) afforded a pale yellow solid. The title compound was obtained as a white solid after trituration with diethyl ether (0.026 g, 42%). 1H-NMR (500 MHz, DMSO-d6) 2.60 (br s, 4H, piperazine N(CH2)2), 3.57 (s, 2H, NCH2—C6H4Cl), 3.66 (br s, 4H, piperazine N(CH2)2), 3.84 (s, 3H, OCH3), 7.10 (d, J=8.1 Hz, 2H) and 8.13 (d, J=8.1 Hz, 2H) (3,5-C6H4OMe and 2,6-C6H4OMe), 7.41 (m, 4H, C6H4Cl), 8.20 (s, 1H, imidazo[4,5-b]pyridine 5-H), 13.37 (br s, 1H, imidazo[4,5-b]pyridine N—H);

Workup

  1. temperatureto cool to room temperature
  2. concentrationconcentrated in vacuo
  3. customThe residue was absorbed on silica gel
  4. washthe free-running powder was placed on a 10 g isolute silica column and elution with a gradient of methanol (0 to 3%) in ethyl acetate/dichloromethane (v:v; 2:3)
  5. customafforded a pale yellow solid

Sources & evidence

ORD record
ord-79aebdcd6dc840538293f4028988d8b5
Source dataset
uspto-grants-2012_01
Patent number
US08088761B2

Reaction notes

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