Sodium Acetate → Ethyl 7-(Acetyloxy)-2-methyl-1-benzothiophene-5-carboxylate

HRID 1177303Notes

Reaction equation

HRID 1177303 reaction equation
[C:1]([O-:4])(=[O:3])[CH3:2].[Na+].[CH2:6]([O:8][C:9]([C:11](=[CH:16][C:17]1[CH:21]=[C:20]([CH3:22])[S:19][CH:18]=1)[CH2:12][C:13](O)=O)=[O:10])[CH3:7]>C(OC(=O)C)(=O)C.ClCCl>[C:1]([O:4][C:13]1[C:18]2[S:19][C:20]([CH3:22])=[CH:21][C:17]=2[CH:16]=[C:11]([C:9]([O:8][CH2:6][CH3:7])=[O:10])[CH:12]=1)(=[O:3])[CH3:2]

Participants

5

Reactant 2

HCID 517045Sodium AcetateHCID 667555563-(Ethoxycarbonyl)-4-(5-methyl-3-thienyl)but-3-enoic Acid

Product 1

HCID 59560166Ethyl 7-(Acetyloxy)-2-methyl-1-benzothiophene-5-carboxylateYield 42%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 7918Acetic AnhydrideSolvent

Procedure

Sodium acetate (30 g, 0.36 mol) was added under vigorous stirring to a solution of 3-(ethoxycarbonyl)-4-(5-methyl-3-thienyl)but-3-enoic acid (30 g, 0.12 mol) in 300 mL of acetic anhydride. The reaction mixture was refluxed for 3 h and evaporated in vacuum (˜20 mmHg) at 70° C. until the solvent distillation ceased. The obtained crude product was suspended in 500 mL of dichloromethane. The suspension was filtered. The precipitate was washed by 250 mL of dichloromethane. The combined solutions were washed by 350 mL of a saturated aqueous solution of NaHCO3 and evaporated in vacuum to dryness. The obtained crude product was chromatographed on a layer of silica gel (250×150 mm) with hexane/ethyl acetate mixture (3:1) to give the desired product 14 g (50 mmol, 42%) as a solid.

Workup

  1. temperatureThe reaction mixture was refluxed for 3 h
  2. customevaporated in vacuum (˜20 mmHg) at 70° C. until the solvent distillation
  3. customThe obtained crude product
  4. filtrationThe suspension was filtered
  5. washThe precipitate was washed by 250 mL of dichloromethane
  6. washThe combined solutions were washed by 350 mL of a saturated aqueous solution of NaHCO3
  7. customevaporated in vacuum to dryness
  8. customThe obtained crude product
  9. customwas chromatographed on a layer of silica gel (250×150 mm) with hexane/ethyl acetate mixture (3:1)

Sources & evidence

ORD record
ord-95b5845e610347c3a94b4e8da639cd59
Source dataset
uspto-grants-2010_11
Patent number
US07842713B2

Reaction notes

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