O-Phenylenediamine → Benzimidazole, 2-trichloromethyl-

HRID 2189470Notes

Reaction equation

HRID 2189470 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].CO[C:11](=N)[C:12]([Cl:15])([Cl:14])[Cl:13]>C(O)(=O)C>[Cl:13][C:12]([Cl:15])([Cl:14])[C:11]1[NH:8][C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=2[N:7]=1

Participants

4

Reactant 2

HCID 7243O-PhenylenediamineHCID 100479Methyl 2,2,2-trichloroacetimidate

Product 1

HCID 77133Benzimidazole, 2-trichloromethyl-

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

1,2-phenylenediamine (1 g, 9.25 mmol) was dissolved in acetic acid (30 ml), methyltrichloroacetimidate (1.26 ml, 10.18 mmol) was added to the solution at 0° C. and then the mixture was stirred at room temperature. After the reaction was completed, the product was washed, filtered, and dried to obtain 2-trichloromethyl-1H-benzoimidazole. 2-trichloromethyl-1H-benzoimidazole thus obtained was added to 2 N aqueous sodium hydroxide solution (50 ml) at 0° C. and the mixture was stirred at the temperature for 2 hours. The mixture was acidified with 2 N aqueous hydrochloric, acid (pH=3) and the resulting crystals were washed and filtered to obtain 1H-benzoimidazole-2-carboxylic acid (1.2 g, 2-step yield: 80%).

Workup

  1. washthe product was washed
  2. filtrationfiltered
  3. customdried

Sources & evidence

ORD record
ord-82ae47e6ced64b60919e90be0ffe598a
Source dataset
uspto-grants-2012_12
Patent number
US08324246B2

Reaction notes

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