Hydrochloric Acid → 2-(3,4-Dimethoxyphenyl)-1-(thien-2-yl)ethanone

HRID 378241Notes

Reaction equation

HRID 378241 reaction equation
[Li][C:2]1[S:3][CH:4]=[CH:5][CH:6]=1.CN(OC)[C:9](=[O:21])[CH2:10][C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[C:13]([O:19][CH3:20])[CH:12]=1.Cl>C1COCC1.CCOCC>[CH3:20][O:19][C:13]1[CH:12]=[C:11]([CH2:10][C:9]([C:2]2[S:3][CH:4]=[CH:5][CH:6]=2)=[O:21])[CH:16]=[CH:15][C:14]=1[O:17][CH3:18]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 112186512-(3,4-dimethoxyphenyl)-N-methoxy-N-methylacetamideHCID 178418439HCID 178418439, compound

Product 1

HCID 114254962-(3,4-Dimethoxyphenyl)-1-(thien-2-yl)ethanoneYield 50.4%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

2-Lithiothiophene (1.0 M in THF, 33.0 mL, 33.0 mmol, Aldrich Chemical Co.) was added dropwise to N-methyl-N-methoxy-(3,4-dimethoxyphenyl)acetamide (5.26 g, 22.0 mmol) in anhydrous THF at -78° C. The reaction was allowed to proceed 90 min., then diluted with 100 mL Et2O and poured into 1 N aq. HCl. The aqueous phase was extracted with Et2O and the combined organic fraction was washed with brine, dried (Na2SO4), and concentrated in vacuo. Flash chromatography (25% EtOAc/hexanes) yielded 2.91 g (50%) 2-(3,4-dimethoxyphenyl)-1-(thien-2-yl)ethanone as a brown oil. MS 263 (M+H)+, 280 (M+NH4)+.

Workup

  1. extractionThe aqueous phase was extracted with Et2O
  2. washthe combined organic fraction was washed with brine
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d9c70e3175874c2d9820b221a4f1fd47
Source dataset
uspto-grants-2000_02
Patent number
US06030969

Reaction notes

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