Propanoic acid, 3-((2-methoxy-2-oxoethyl)thio)-, methyl ester → 2-Thiophenecarboxylic acid, tetrahydro-3-oxo-, methyl ester

HRID 595057Notes

Reaction equation

HRID 595057 reaction equation
[Li].[CH3:2][O:3][C:4](=[O:13])[CH2:5][S:6][CH2:7][CH2:8][C:9](OC)=[O:10]>CO>[O:10]=[C:9]1[CH2:8][CH2:7][S:6][CH:5]1[C:4]([O:3][CH3:2])=[O:13]

Participants

4

Reactant 2

HCID 81891Propanoic acid, 3-((2-methoxy-2-oxoethyl)thio)-, methyl esterHCID 3028194Lithium

Product 1

HCID 1028702-Thiophenecarboxylic acid, tetrahydro-3-oxo-, methyl esterYield 43.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Lithium metal (2.70 g, 390.15 mmol) was added to 500 mL of methanol in an ice-bath. Then at rt methyl 3-(2-methoxy-2-oxoethylthio)propanoate (50.0 g, 260.10 mmol) was added dropwise to the solution. The reaction mixture was stirred overnight. The resulting reaction mixture was evaporated to remove the solvent. The mixture was neutralized to pH=7-8 with 3N HCl and extracted with dichloromethane. The organic layers were combined, washed with brine, dried over anhydrous Na2SO4, filtered and evaporated. The crude residue obtained contained the target as the only isolable product. Purification by column chromatography on silica gel (eluent: PE/EA=20/1-5/1) provided methyl 3-oxo-tetrahydrothiophene-2-carboxylate as a colourless oil (18.0 g, 43%).

Workup

  1. customThe resulting reaction mixture
  2. customwas evaporated
  3. customto remove the solvent
  4. extractionextracted with dichloromethane
  5. washwashed with brine
  6. dry with materialdried over anhydrous Na2SO4
  7. filtrationfiltered
  8. customevaporated
  9. customThe crude residue obtained
  10. customPurification by column chromatography on silica gel (eluent: PE/EA=20/1-5/1)

Sources & evidence

ORD record
ord-35bde052d3db4030a1b345e35d1e13d9
Source dataset
uspto-grants-2016_01
Patent number
US09242993B2

Reaction notes

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