Acetic Acid → 1-(prop-2-en-1-yl)-1H-1,3-benzodiazole-2-carbaldehyde

HRID 2231235Notes

Reaction equation

HRID 2231235 reaction equation
[CH2:1]([N:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[N:6]=[CH:5]1)[CH:2]=[CH2:3].C([Li])CCC.[CH:18](OCC)=[O:19].C(O)(=O)C>O1CCCC1.CCCCCC>[CH2:1]([N:4]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[N:6]=[C:5]1[CH:18]=[O:19])[CH:2]=[CH2:3]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 8025Ethyl formateHCID 5941171-AllylbenzimidazoleHCID 178418339Butyllithium

Product 1

HCID 9625211-(prop-2-en-1-yl)-1H-1,3-benzodiazole-2-carbaldehyde

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Conditions

Temperature
-20 °C

Procedure

To a solution of 10 g (0.053 mole) of 1-allylbenzimidazole in 75 ml of tetrahydrofuran cooled to -78° C. was added 20.68 ml (0.053 mole) of 2.6M n-butyllithium in hexane over a period of 15 minutes. After 30 minutes of stirring 4.28 ml (0.053 mole) of ethyl formate was added and the reaction allowed to stir for one hour. Acetic acid (3.03 ml, 0.053 mole) was added, the cooling bath removed and the mixture allowed to warm to -20° C. The mixture was poured into water and the product extracted (3×100 ml) with ethyl acetate. The extracts were combined, dried over magnesium sulfate and concentrated to a brown oil which was chromatographed on 350 g of silica gel using ethyl acetate-chloroform as the eluent, 2.3 g.

Workup

  1. additionwas added
  2. customthe cooling bath removed
  3. additionThe mixture was poured into water
  4. extractionthe product extracted (3×100 ml) with ethyl acetate
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated to a brown oil which
  7. customwas chromatographed on 350 g of silica gel

Sources & evidence

ORD record
ord-370b222dd28145c58223e588287097fa
Source dataset
uspto-grants-1988_11
Patent number
US04782050

Reaction notes

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