Methyl iodide → Methyl 4-bromo-3-methoxythiophene-2-carboxylate

HRID 639295Notes

Reaction equation

HRID 639295 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[C:8]([Br:11])[C:9]=1[OH:10])=[O:4].[C:12](=O)([O-])[O-].[K+].[K+].IC>CC(C)=O>[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[C:8]([Br:11])[C:9]=1[O:10][CH3:12])=[O:4]

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 2777611Methyl 4-bromo-3-hydroxythiophene-2-carboxylate

Product 1

HCID 2736824Methyl 4-bromo-3-methoxythiophene-2-carboxylateYield 106.2%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

Methyl-4-bromo-3-hydroxy-2-thiophenecarboxylate (20 g, 84.36 mmol) was dissolved in 400 mL of acetone. Potassium carbonate (58 g, 420.3 mmol) was added followed by iodomethane (45 mL, 424 mmol). The resulting mixture was heated at reflux for 4.5 h. After cooling, the mixture was filtered through a thin Celite pad, rinsing with methylene chloride. The filtrate was concentrated in vacuo to give 22.5 g of methyl-4-bromo-3-methoxy-2-thiophenecarboxylate (crude, 100%, MH+=251.0) as a dark green solid.

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureat reflux for 4.5 h
  3. temperatureAfter cooling
  4. filtrationthe mixture was filtered through a thin Celite pad
  5. washrinsing with methylene chloride
  6. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-2b16a1a8c2ce426d896744619769074b
Source dataset
uspto-grants-2010_04
Patent number
US07691856B2

Reaction notes

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