O-Phenylenediamine → 2-(5-Ethyl-2-pyridyl)benzimidazole

HRID 1449022Notes

Reaction equation

HRID 1449022 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[CH2:9]([C:11]1[CH:12]=[CH:13][C:14]([C:17](O)=O)=[N:15][CH:16]=1)[CH3:10].C(=O)([O-])[O-].[Na+].[Na+]>O>[CH2:9]([C:11]1[CH:12]=[CH:13][C:14]([C:17]2[NH:7][C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=3[N:8]=2)=[N:15][CH:16]=1)[CH3:10]

Participants

5

Reactant 3

HCID 7243O-PhenylenediamineHCID 10340Sodium CarbonateHCID 1203755-Ethylpicolinic acid

Product 1

HCID 497462-(5-Ethyl-2-pyridyl)benzimidazole

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

11.3 g. of o-phenylenediamine, 15.1 g. of 5-ethylpicolinic acid and 80 g. of polyphosphoric acid were heated at 180°-190° C. under a nitrogen gas current for 3 hours with stirring. The reaction mixture was diluted with 1,000 ml. of water and then neutralized with sodium carbonate. The resulting crystals were filtered off, dried and recrystallized from ethyl acetate to give 17.1 g. of colorless needles of the product (78% of theory). M.P. 172.5°-173° C.

Workup

  1. additionThe reaction mixture was diluted with 1,000 ml
  2. filtrationThe resulting crystals were filtered off
  3. customdried
  4. customrecrystallized from ethyl acetate
  5. customto give 17.1 g

Sources & evidence

ORD record
ord-cdd3ddee56b246988693e8ee6b0a7a20
Source dataset
uspto-grants-1980_02
Patent number
US04188486

Reaction notes

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