Benzanilide → 1H-Benzimidazole, 1,2-diphenyl-

HRID 1028373Notes

Reaction equation

HRID 1028373 reaction equation
I[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[N+:8]([O-])=O.[C:11]1([NH:17][C:18](=O)[C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.CNCCN.P([O-])([O-])([O-])=O.[K+].[K+].[K+]>C1(C)C=CC=CC=1.[Cu]I.[Fe].C(O)(=O)C>[C:3]1([N:8]2[C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=3[N:17]=[C:18]2[C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH:4]=[CH:5][CH:6]=[CH:7][CH:2]=1

Participants

9

Reactant 4

HCID 7168BenzanilideHCID 8014N-MethylethylenediamineHCID 62657Potassium Phosphate, TribasicHCID 69115o-Iodonitrobenzene

Product 1

HCID 1376611H-Benzimidazole, 1,2-diphenyl-Yield 67%

Reagents, catalysts & solvents 4

HCID 23925IronCatalyst2×HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 176Acetic AcidSolventHCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

A reaction tube containing 1-iodo-2-nitrobenzene (124 mg, 0.5 mmol), N-phenylbenzamide (118 mg, 0.6 mmol), CuI (4.8 mg, 0.025 mmol), N-methylethylenediamine (4.4 μL, 0.05 mmol), potassium phosphate (212 mg, 1 mmol) in dry toluene (1.5 mL) was purged with dry argon for 3 min. After heating at 100° C. for 18 h, the iron powder (10 mol.-eq.) and glacial acetic acid (5 mL) are directly added. Then the reaction mixture is heated at reflux for 30 min. An additional 10 mol.-eq. of iron powder are added and the reaction mixture is heated at reflux for further 30 min. The solvents were removed under reduced pressure and the crude was extracted with ethyl acetate against saturated sodium bicarbonate solution. The organic phase was dried and the solvent was removed on a rotary evaporator. Then the residue was purified by preparative HPLC, affording the title compound as a solid (90 mg, 67% yield).

Workup

  1. customwas purged with dry argon for 3 min
  2. temperatureThen the reaction mixture is heated
  3. temperatureat reflux for 30 min
  4. temperaturethe reaction mixture is heated
  5. temperatureat reflux for further 30 min
  6. customThe solvents were removed under reduced pressure
  7. extractionthe crude was extracted with ethyl acetate against saturated sodium bicarbonate solution
  8. customThe organic phase was dried
  9. customthe solvent was removed on a rotary evaporator
  10. customThen the residue was purified by preparative HPLC

Sources & evidence

ORD record
ord-dfbaa61ba4c74fe79b2e41d931bfd021
Source dataset
uspto-grants-2014_05
Patent number
US08735586B2

Reaction notes

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