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

HRID 1646535Notes

Reaction equation

HRID 1646535 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-de6ba547270f47dd97159849458bd8d6
Source dataset
uspto-grants-1993_01
Patent number
US05180723

Reaction notes

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