1,2-Dibromoethane → 1-(4-nitrophenyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazole

HRID 587425Notes

Reaction equation

HRID 587425 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([NH:10][C:11]2[NH:15][C:14]3[CH:16]=[CH:17][CH:18]=[CH:19][C:13]=3[N:12]=2)=[CH:6][CH:5]=1)([O-:3])=[O:2].[H-].[Na+].Br[CH2:23][CH2:24]Br>CN(C=O)C>[N+:1]([C:4]1[CH:5]=[CH:6][C:7]([N:10]2[C:11]3=[N:12][C:13]4[CH:19]=[CH:18][CH:17]=[CH:16][C:14]=4[N:15]3[CH2:24][CH2:23]2)=[CH:8][CH:9]=1)([O-:3])=[O:2]

Participants

5

Reactant 3

HCID 78391,2-DibromoethaneHCID 24758Sodium hydrideHCID 5219340N-(4-nitrophenyl)-1H-benzimidazol-2-amine

Product 1

HCID 585774441-(4-nitrophenyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazoleYield 5.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A mixture of N-(4-nitrophenyl)-1H-benzimidazol-2-amine (1.00 g) in DMF (20 mL) at ambient temperature was treated with a 60% dispersion of sodium hydride in mineral oil (393 mg) then stirred for 5 min. The mixture was treated with a solution of 1,2-dibromoethane (738 mg) in DMF (1 mL) then stirred at ambient temperature for 1 h. After this time, the reaction mixture was quenched with saturated aqueous ammonium chloride (10 mL), diluted with water (80 mL) and extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with 5% aqueous lithium chloride (2×50 mL) then brine (50 mL), dried over sodium sulfate, and filtered and the filtrate was concentrated under reduced pressure. The residue obtained was purified by chromatography (silica, heptane to 1:1 ethyl acetate/heptane) to afford 1-(4-nitrophenyl)-2,3-dihydro-1H-imidazo[1,2-a]benzimidazole (63 mg) as a yellow solid.

Workup

  1. stirringthen stirred at ambient temperature for 1 h
  2. customAfter this time, the reaction mixture was quenched with saturated aqueous ammonium chloride (10 mL)
  3. additiondiluted with water (80 mL)
  4. extractionextracted with ethyl acetate (2×100 mL)
  5. washThe combined organic layers were washed with 5% aqueous lithium chloride (2×50 mL)
  6. dry with materialbrine (50 mL), dried over sodium sulfate
  7. filtrationfiltered
  8. concentrationthe filtrate was concentrated under reduced pressure
  9. customThe residue obtained
  10. customwas purified by chromatography (silica, heptane to 1:1 ethyl acetate/heptane)

Sources & evidence

ORD record
ord-c025645c5d7b4b169a88fdb75e00f4a5
Source dataset
uspto-grants-2016_01
Patent number
US09226921B2

Reaction notes

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