4-Fluorobenzene-1,2-diamine → 6-Fluoro-2-methyl-1H-benzimidazole

HRID 1197651Notes

Reaction equation

HRID 1197651 reaction equation
Cl.[C:2](=N)(OCC)[CH3:3].[F:8][C:9]1[CH:14]=[CH:13][C:12]([NH2:15])=[C:11]([NH2:16])[CH:10]=1>C(O)C>[CH3:2][C:3]1[NH:16][C:11]2[CH:10]=[C:9]([F:8])[CH:14]=[CH:13][C:12]=2[N:15]=1

Participants

4

Reactant 2

HCID 1645844-Fluorobenzene-1,2-diamineHCID 2724290Ethanimidic acid, ethyl ester, hydrochloride (1:1)

Product 1

HCID 27753756-Fluoro-2-methyl-1H-benzimidazoleYield 51.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl acetimidate hydrochloride (37.1 g, 0.3 mol) was added to a stirred suspension of 4-fluoro-ortho-phenylenediamine (12.6 g, 0.1 mol) in ethanol (150 ml) at 0° C. The mixture was allowed to warm up to room temperature and stirred overnight. The solvent was removed under reduced pressure and the residue extracted into ethyl acetate (100 ml), washed with water (3×100 ml), dried over anhydrous magnesium sulphate, filtered and evaporated. Crystallisation from ethyl acetate gave 2-methyl-5-fluorobenzimidazole (7.7 g, 51%) as a brown crystalline solid.

Workup

  1. customThe solvent was removed under reduced pressure
  2. extractionthe residue extracted into ethyl acetate (100 ml)
  3. washwashed with water (3×100 ml)
  4. dry with materialdried over anhydrous magnesium sulphate
  5. filtrationfiltered
  6. customevaporated
  7. customCrystallisation from ethyl acetate

Sources & evidence

ORD record
ord-3cb2206753f443b79ce6ac3a505d167d
Source dataset
uspto-grants-1994_01
Patent number
US05276153

Reaction notes

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