Reaction #1810789

Reaction equation

3,4-dihexoxythiophene

thiophene

sulfuric acid

thiodiglycolic acid

→

thiodiglycolic acid diethylester

Yield 90.0%

Solvents

ethanol

Conditions

Workup

1. 1
   Otherto prepare a reaction solution
2. 2
   Temperaturethe reaction solution was refluxing
3. 3
   Temperatureunder heating for 12 hr
4. 4
   OtherSubsequently, substantially 500 mL of water and ethanol was removed from the reaction solution
5. 5
   workup.ADDITIONFurthermore, 400 mL of ethanol was added
6. 6
   Temperatureafter refluxing
7. 7
   Temperatureunder heating for 20 hr
8. 8
   workup.ADDITIONthe reaction solution was added water
9. 9
   Extractionto extract with ether
10. 10
    DryingA layer of ether was dried with magnesium sulfate
11. 11
    Filtrationby filtering
12. 12
    Concentrationconcentrating
13. 13
    workup.DISTILLATIONThe residue was distilled under reduced pressure of 200 Pa

Procedure

An example of synthesizing 3,4-dihexoxythiophene as a thiophene monomer is shown below. 2 mL of sulfuric acid was added in an ethanol solution (800 mL) of thiodiglycolic acid (250 g, 1.67 mol) to prepare a reaction solution, then the reaction solution was refluxing under heating for 12 hr after stirring for 24 hr. Subsequently, substantially 500 mL of water and ethanol was removed from the reaction solution according to azeotropy. Furthermore, 400 mL of ethanol was added and after refluxing under heating for 20 hr, the reaction solution was added water to extract with ether. A layer of ether was dried with magnesium sulfate, followed by filtering and concentrating. The residue was distilled under reduced pressure of 200 Pa and a temperature of 100 to 110 degree centigrade, and thereby thiodiglycolic acid diethylester was obtained at a yield of 90 percent.

Source