Hydrochloric Acid → 1-Benzothiophene-2-carbaldehyde

HRID 2396540Notes

Reaction equation

HRID 2396540 reaction equation
C([Li])CCC.CN(C)CCN(C)C.[S:14]1[C:18]2[CH:19]=[CH:20][CH:21]=[CH:22][C:17]=2[CH:16]=[CH:15]1.CN(C)[CH:25]=[O:26].Cl>O1CCCC1.CCCCCC.C(OCC)(=O)C>[S:14]1[C:15]([CH:25]=[O:26])=[CH:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][C:18]1=2

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 6228DimethylformamideHCID 7221Benzo(B)ThiopheneHCID 8037N,N,N',N'-Tetramethylethylenediamine2×HCID 178418339Butyllithium2×

Product 1

HCID 7365001-Benzothiophene-2-carbaldehydeYield 69%

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

Butyllithium (54 mL, 134 mmol) is added dropwise to a solution of N,N,N',N'-tetramethylethylenediamine (15.57 g, 134 mmol) in tetrahydrofuran under nitrogen at 0° C. The reaction mixture is treated dropwise with a solution of benzothiophene (15.00 g, 112 mmol) in tetrahydrofuran, warmed to room temperature, treated with additional N,N,N',N'-tetramethylethylenediamine (15.57 g, 134 mmol) and butyllithium (54 mL, 134 mmol), stirred at room temperature for 13 hours, cooled to 0° C., treated with N,N-dimethylformamide (24.40 g, 336 mmol), warmed to room temperature, stirred for five hours, poured into one molar hydrochloric acid and extracted with ether. The combined organic extracts are washed sequentially with water and brine, dried over Na2SO4 and concentrated in vacuo to obtain an orange oil. Flash chromatography of the oil using silica gel and a 15% ethyl acetate in hexane 25 solution gives the title product as an orange oil (12.51 g, 69%).

Workup

  1. temperaturecooled to 0° C.
  2. temperaturewarmed to room temperature
  3. stirringstirred for five hours
  4. extractionextracted with ether
  5. washThe combined organic extracts are washed sequentially with water and brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated in vacuo
  8. customto obtain an orange oil

Sources & evidence

ORD record
ord-9fe06debe1234fe299b43b2f8ae54c5c
Source dataset
uspto-grants-1996_02
Patent number
US05492925

Reaction notes

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