Methanol → 4-(2-Thienyl)butanoic acid methyl ester

HRID 1178616Notes

Reaction equation

HRID 1178616 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][CH2:7][CH2:8][C:9]([OH:11])=[O:10].S(=O)(=O)(O)O.[CH3:17]O>>[CH3:17][O:10][C:9](=[O:11])[CH2:8][CH2:7][CH2:6][C:2]1[S:1][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 783864-(2-Thienyl)Butyric Acid

Product 1

HCID 1407664-(2-Thienyl)butanoic acid methyl ester

Procedure

A mixture of 4-(2-thienyl)butyric acid (4.25 g, 25.0 mmol) and 3 mL of concentrated sulfuric acid in 25 mL of methanol is heated at reflux for 2 hours. The reaction mixture is cooled to room temperature and partitioned between ethyl acetate and saturated aqueous sodium carbonate solution. The organic layer is separated and passed through a short pad of silica gel. The filtrate is concentrated and purified by flash column chromatography eluting with 1:5 ethyl acetate:hexane to provide 4.02 g of 4-thiophen-2-yl-butyric acid methyl ester as a yellow oil, 1H NMR (DMSO-d6) δ 1.85 (quintet, J=7 Hz, 2H), 2.35 (t, J=7 Hz, 2H), 2.81 (t, J=7 Hz, 2H), 3.59 (s, 3H), 6.84 (m, 1 H), 6.95 (m, 1 H), 7.32 (dd, J=5, 1 Hz, 1H); MS 185.0 (M+H)+

Workup

  1. temperatureis heated
  2. temperatureat reflux for 2 hours
  3. custompartitioned between ethyl acetate and saturated aqueous sodium carbonate solution
  4. customThe organic layer is separated
  5. concentrationThe filtrate is concentrated
  6. custompurified by flash column chromatography
  7. washeluting with 1:5 ethyl acetate

Sources & evidence

ORD record
ord-e7b935dd302b40d2b1111f08492c7f14
Source dataset
uspto-grants-2007_10
Patent number
US07276519B2

Reaction notes

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