O-Phenylenediamine → Benzimidazole, 2-(6-ethyl-2-pyridyl)-

HRID 1701304Notes

Reaction equation

HRID 1701304 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[N:16]=[C:15]([C:17](O)=O)[CH:14]=[CH:13][CH:12]=1)[CH3:10].C(=O)([O-])[O-].[Na+].[Na+]>O>[CH2:9]([C:11]1[N:16]=[C:15]([C:17]2[NH:7][C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=3[N:8]=2)[CH:14]=[CH:13][CH:12]=1)[CH3:10]

Participants

5

Reactant 3

HCID 7243O-PhenylenediamineHCID 10340Sodium CarbonateHCID 113605646-Ethylpicolinic acid

Product 1

HCID 49747Benzimidazole, 2-(6-ethyl-2-pyridyl)-

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

2.2 g. of o-phenylenediamine, 3 g. of 6-ethylpicolinic acid and 15 g. of polyphosphoric acid were heated at 160°-180° C. under nitrogen gas current for 2 hours with stirring. The reaction mixture was diluted with 200 ml. of water and neutralized with sodium carbonate. The resulting precipitate was filtered off, dried, subjected to silica gel column chromatography (developed with 1:1 by volume mixture of benzene and ethyl acetate) and recrystallized from benzene. 3.3 g. of colorless needles of the product (74% of theory) was obtained. M.P. 161°-161.5° C.

Workup

  1. additionThe reaction mixture was diluted with 200 ml
  2. filtrationThe resulting precipitate was filtered off
  3. customdried
  4. additionsubjected to silica gel column chromatography (developed with 1:1 by volume mixture of benzene and ethyl acetate)
  5. customrecrystallized from benzene
  6. customof colorless needles of the product (74% of theory) was obtained

Sources & evidence

ORD record
ord-522ab668fd9c4ca3bb1cf8c7c3fd37b1
Source dataset
uspto-grants-1980_03
Patent number
US04192880

Reaction notes

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