Acetic Acid → 1H-Benzimidazole, 2-propoxy-

HRID 1941356Notes

Reaction equation

HRID 1941356 reaction equation
[C:1]1([NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH2:7].[C:9](O)(=O)C.[C:13]([O:16][CH2:17][CH3:18])(=O)C>C([O-])([O-])([O-])OCCC>[CH2:17]([O:16][C:13]1[NH:7][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[N:8]=1)[CH2:18][CH3:9]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 7243O-PhenylenediamineHCID 8857Ethyl Acetate

Product 1

HCID 30406051H-Benzimidazole, 2-propoxy-

Reagents, catalysts & solvents 1

HCID 86586169Propyl orthocarbonateSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of o-phenylenediamine (2 g) in propyl orthocarbonate (5 ml) was added acetic acid (1.1 ml) and the solution was stirred at 80° C. for 3 hours. To the reaction mixture was added ethyl acetate, and the solution was washed with an aqueous solution of sodium hydrogen carbonate and water, then dried (Na2SO4), followed by concentration to dryness. The concentrate was purified by column chromatography on silica gel to give crystals. Recrystallization from ethyl acetate-benzene afforded colorless crystals (1.54 g, 47%), m.p. 163°-164° C.

Workup

  1. washthe solution was washed with an aqueous solution of sodium hydrogen carbonate and water
  2. dry with materialdried (Na2SO4)
  3. concentrationfollowed by concentration to dryness
  4. customThe concentrate was purified by column chromatography on silica gel
  5. customto give crystals
  6. customRecrystallization from ethyl acetate-benzene afforded colorless crystals (1.54 g, 47%), m.p. 163°-164° C.

Sources & evidence

ORD record
ord-0971a54ed8c84ffd83f32d4f8efd0d7a
Source dataset
uspto-grants-1997_12
Patent number
US05703110

Reaction notes

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