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

HRID 612758Notes

Reaction equation

HRID 612758 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

Sources & evidence

ORD record
ord-3ccc118d67e74ab798db017b63989585
Source dataset
uspto-grants-1999_12
Patent number
US06004989

Reaction notes

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