1,10-Phenanthroline → 1-Phenyl-1H-benzoimidazole

HRID 1726364Notes

Reaction equation

HRID 1726364 reaction equation
[N:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[NH:3][CH:2]=1.C(=O)([O-])[O-].[Cs+].[Cs+].I[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.N1C2C(=CC=C3C=2N=CC=C3)C=CC=1>[Cu]I.CCCCCC.CN(C)C=O>[C:17]1([N:1]2[C:5]3[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=3[N:3]=[CH:2]2)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

8

Reactant 4

HCID 13181,10-PhenanthrolineHCID 5798BenzimidazoleHCID 10796Cesium carbonateHCID 11575Iodobenzene

Product 1

HCID 6066691-Phenyl-1H-benzoimidazoleYield 45%

Reagents, catalysts & solvents 3

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 6228DimethylformamideSolventHCID 8058HexaneSolvent

Conditions

Temperature
110 °C

Procedure

In the dark, an oven-dried 50 ml round-bottomed flask containing a stir bar was charged with CuI (0.171 g, 0.1 eq.), benzimidazole (1.273 g, 1.2 eq.), and cesium carbonate (6.138 g, 2.1 eq.) respectively. The round-bottomed flask with the contents was sealed with septa and degassed with argon for 15 minutes. Iodobenzene (1 ml, 1 eq.), 1,10-Phenanthroline (0.323 g, 0.2 eq.), and dimethylformamide (25 ml) were then successively added into the round-bottomed flask under a continuous flow of argon. The reaction mixture was degassed with argon for 30 minutes. The reaction was stirred with heating via an oil bath at 110° C. for 24 hours in the dark under nitrogen. The reaction mixture was cooled to ambient temperature and concentrated in vacuo. 10 ml of ethyl acetate was added into the concentrated reaction mixture. It was then filtered and washed with 30 ml of ethyl acetate. The filtrate was concentrated under vacuo to give the crude product. The crude product was purified by column chromatography on silica gel (40% ethyl acetate: 60% hexane as the eluent) providing 0.780 g of 1-Phenyl benzoimidazole (45% yield) as yellow liquid.

Workup

  1. additionIn the dark, an oven-dried 50 ml round-bottomed flask containing a stir bar
  2. customThe round-bottomed flask with the contents was sealed with septa
  3. customdegassed with argon for 15 minutes
  4. customThe reaction mixture was degassed with argon for 30 minutes
  5. temperatureThe reaction mixture was cooled to ambient temperature
  6. concentrationconcentrated in vacuo
  7. addition10 ml of ethyl acetate was added into the concentrated reaction mixture
  8. filtrationIt was then filtered
  9. washwashed with 30 ml of ethyl acetate
  10. concentrationThe filtrate was concentrated under vacuo
  11. customto give the crude product
  12. customThe crude product was purified by column chromatography on silica gel (40% ethyl acetate

Sources & evidence

ORD record
ord-d6599ff00035437d86e9844acd56fe4e
Source dataset
uspto-grants-2009_02
Patent number
US07491823B2

Reaction notes

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