3-Pyridinecarboxaldehyde → 5-bromo-1-methyl-2-(pyridin-3-yl)-1H-benzimidazole-6-carbonitrile

HRID 1048995Notes

Reaction equation

HRID 1048995 reaction equation
[NH2:1][C:2]1[C:9]([NH:10][CH3:11])=[CH:8][C:5]([C:6]#[N:7])=[C:4]([Br:12])[CH:3]=1.[CH:13](=O)[C:14]1[CH:19]=[CH:18][CH:17]=[N:16][CH:15]=1.OOS([O-])=O.[K+]>CN(C=O)C.O>[Br:12][C:4]1[C:5]([C:6]#[N:7])=[CH:8][C:9]2[N:10]([CH3:11])[C:13]([C:14]3[CH:15]=[N:16][CH:17]=[CH:18][CH:19]=3)=[N:1][C:2]=2[CH:3]=1

Participants

6

Reactant 3

HCID 103713-PyridinecarboxaldehydeHCID 23707502Potassium hydroxy sulfiteHCID 666852384-Amino-2-bromo-5-(methylamino)benzonitrile

Product 1

HCID 666925455-bromo-1-methyl-2-(pyridin-3-yl)-1H-benzimidazole-6-carbonitrile

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

To solution of 4-amino-2-bromo-5-(methylamino)benzonitrile (0.2 g, 0.0008 mol) and nicotinaldehyde (0.094 g, 0.0008 mol) in DMF (5 ml) and H2O (2 ml) was added OXONE® monopersulphate (0.43 g, 0.0007 mol). Reaction mass was stirred at room temperature for 3 h. The reaction mixture was quenched with 10% K2CO3 solution to PH˜8-10 and extracted with EtOAc (3×20 ml). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated under vacuum to afford the crude compound, which was purified by column chromatography to obtain title compound 5-bromo-1-methyl-2-(pyridin-3-yl)-1H-benzimidazole-6-carbonitrile. (3971H NMR (400 MHz, DMSO-d6), δ: 9.08 (s, 1H), 8.80-8.79 (d, J=4 Hz, 1H), 8.53 (s, 1H), 8.34-8.32 (d, J=7.2 Hz, 1H), 8.23 (s, 1H), 7.67-7.63 (m, 1H), 3.96 (s, 3H). MS (M+1): 313.12, Purity 93.84%.

Workup

  1. customReaction mass
  2. customThe reaction mixture was quenched with 10% K2CO3 solution to PH˜8-10
  3. extractionextracted with EtOAc (3×20 ml)
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated under vacuum
  7. customto afford the crude compound, which
  8. customwas purified by column chromatography

Sources & evidence

ORD record
ord-0bedaaa24fea4685ab0568adec368ddb
Source dataset
uspto-grants-2016_07
Patent number
US09382226B2

Reaction notes

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