(E)-3-(benzo[b]thienyl)-2-propenoic acid ethyl ester → Benzo[b]thiophene-2-propanoic acid ethyl ester

HRID 653956

Reaction equation

HRID 653956 reaction equation
[CH2:1]([O:3][C:4](=[O:16])/[CH:5]=[CH:6]/[C:7]1[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=2[CH:8]=1)[CH3:2]>[Pd].CCO>[CH2:1]([O:3][C:4](=[O:16])[CH2:5][CH2:6][C:7]1[S:11][C:10]2[CH:12]=[CH:13][CH:14]=[CH:15][C:9]=2[CH:8]=1)[CH3:2]

Participants

4

Reactant 1

HCID 10633343(E)-3-(benzo[b]thienyl)-2-propenoic acid ethyl ester

Product 1

HCID 54301546Benzo[b]thiophene-2-propanoic acid ethyl esterYield 96.8%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalyst2×HCID 702EthanolSolvent

Procedure

A mixture of (E)-3-(benzo[b]thienyl)-2-propenoic acid ethyl ester (3.65 g, 15.7 mmol), absolute EtOH (200 mL) and 5% Pd/C (800 mg) was hydrogenated at 1 atm for 3 h. An additional 200 mg of 5% Pd/C was added and the mixture was again hydrogenated for 1.5 h. The mixture was filtered through a pad of Celite washing thoroughly with CH2Cl2. The combined filtrates were concentrated to dryness and the resulting glass was purified by flash chromatography, eluting with 15% EtOAc/hexane to give benzo[b]thiophene-2-propanoic acid ethyl ester (3.55 g, 15.2 mmol) in 96.5% as a glass.

Workup

  1. waitthe mixture was again hydrogenated for 1.5 h
  2. filtrationThe mixture was filtered through a pad of Celite
  3. washwashing thoroughly with CH2Cl2
  4. concentrationThe combined filtrates were concentrated to dryness
  5. customthe resulting glass was purified by flash chromatography
  6. washeluting with 15% EtOAc/hexane

Sources & evidence

ORD record
ord-be618066bc7b4bd98ea3e3a1eb6f5632
Source dataset
uspto-grants-1992_07
Patent number
US05128448

Linked notes

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