Methanol → Methyl 5-methyl-2-thiophenecarboxylate

HRID 1972103Notes

Reaction equation

HRID 1972103 reaction equation
S(Cl)(Cl)=O.[CH3:5][C:6]1[S:10][C:9]([C:11]([OH:13])=[O:12])=[CH:8][CH:7]=1.[CH3:14]O>CCOC(C)=O>[CH3:14][O:12][C:11]([C:9]1[S:10][C:6]([CH3:5])=[CH:7][CH:8]=1)=[O:13]

Participants

5

Reactant 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 747135-Methylthiophene-2-carboxylic acid

Product 1

HCID 580756Methyl 5-methyl-2-thiophenecarboxylateYield 97%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

Add thionyl chloride (153 ml, 2.1 mol) dropwise over 20 min to a solution of 5-methylthiophene-2-carboxylic acid (100 g, 0.703 mol) in MeOH (1 L) at 0° C. and stir. After the addition is complete, heat the reaction mixture to reflux for 3.5 hours. Cool and concentrate in vacuo to give a thick oil. Dilute the oil with EtOAc (500 ml) and sequentially wash with water (300 ml) then brine (300 ml). Dry the organic layer over sodium sulfate. Remove the solids by filtration. Collect the filtrate and concentrate under reduced pressure to give the title compound (106 g, 97%), which is used without further purification. ESI (m/z) 156(M+H).

Workup

  1. additionAfter the addition
  2. temperatureheat the reaction mixture
  3. temperatureto reflux for 3.5 hours
  4. temperatureCool
  5. concentrationconcentrate in vacuo
  6. customto give a thick oil
  7. washsequentially wash with water (300 ml)
  8. dry with materialDry the organic layer over sodium sulfate
  9. customRemove the solids
  10. filtrationby filtration
  11. customCollect the filtrate
  12. concentrationconcentrate under reduced pressure

Sources & evidence

ORD record
ord-5e174aa2d7504487a1c27dc3a6307fd2
Source dataset
uspto-grants-2013_04
Patent number
US08431706B2

Reaction notes

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