Hydrochloric Acid → 1-Benzothiophene-2-carbaldehyde

HRID 374520Notes

Reaction equation

HRID 374520 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 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-f4bb1eec6393487ea5df12f92a632c4a
Source dataset
uspto-grants-1996_01
Patent number
US05480902

Reaction notes

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