Reaction #833534

Reaction equation

Iodobenzene

1,10-Phenanthroline

benzimidazole

cesium carbonate

→

1-Phenyl benzoimidazole

Yield 45.0%

Solvents

dimethylformamide

hexane

Conditions

Workup

1. 1
   workup.ADDITIONIn the dark, an oven-dried 50 ml round-bottomed flask containing a stir bar
2. 2
   OtherThe round-bottomed flask with the contents was sealed with septa
3. 3
   Otherdegassed with argon for 15 minutes
4. 4
   OtherThe reaction mixture was degassed with argon for 30 minutes
5. 5
   TemperatureThe reaction mixture was cooled to ambient temperature
6. 6
   Concentrationconcentrated in vacuo
7. 7
   workup.ADDITION10 ml of ethyl acetate was added into the concentrated reaction mixture
8. 8
   FiltrationIt was then filtered
9. 9
   Washwashed with 30 ml of ethyl acetate
10. 10
    ConcentrationThe filtrate was concentrated under vacuo
11. 11
    Otherto give the crude product
12. 12
    OtherThe crude product was purified by column chromatography on silica gel (40% ethyl acetate

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.

Source