3,4-DIHYDROXY-THIOPHENE-2,5-DICARBOXYLIC ACID DIETHYL ESTER

3,4-DIHYDROXY-THIOPHENE-2,5-DICARBOXYLIC ACID DIETHYL ESTER Property

Melting point:

132-135 °C(lit.)

Boiling point:

153 °C

Density 

1.017 g/mL at 25 °C

refractive index 

n20/D 1.4589

Flash point:

150 °F

storage temp. 

2-8°C(protect from light)

pka

8.40±0.20(Predicted)

Appearance

Light yellow to yellow Solid

InChI

InChI=1S/C10H12O6S/c1-3-15-9(13)7-5(11)6(12)8(17-7)10(14)16-4-2/h11-12H,3-4H2,1-2H3

InChIKey

YOKOBAHUBJPMGP-UHFFFAOYSA-N

SMILES

C1(C(OCC)=O)SC(C(OCC)=O)=C(O)C=1O

Safety

Hazard Codes 

T,Xi

Risk Statements 

61-20/21-36-36/37/38

Safety Statements 

53-45-36-26-36/37

WGK Germany 

3

HS Code 

2934999090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H314Causes severe skin burns and eye damage

H317May cause an allergic skin reaction

H330Fatal if inhaled

H334May cause allergy or asthma symptoms or breathing difficulties if inhaled

H360May damage fertility or the unborn child

H402Harmful to aquatic life

Precautionary statements

P201Obtain special instructions before use.

P202Do not handle until all safety precautions have been read and understood.

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P271Use only outdoors or in a well-ventilated area.

P272Contaminated work clothing should not be allowed out of the workplace.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P284Wear respiratory protection.

P301+P330+P331IF SWALLOWED: Rinse mouth. Do NOT induce vomiting.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P308+P313IF exposed or concerned: Get medical advice/attention.

P333+P313IF SKIN irritation or rash occurs: Get medical advice/attention.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

P405Store locked up.

P501Dispose of contents/container to..…

3,4-DIHYDROXY-THIOPHENE-2,5-DICARBOXYLIC ACID DIETHYL ESTER Chemical Properties,Usage,Production

Chemical Properties

Pale yellow to white solid

Uses

3,4-Dihydroxythiophene-2,5-dicarboxylic Acid Diethyl Ester is an intermediate used to prepare alkylenedioxythiophene monomers to obtain electrochromic conducting polymers.

Synthesis

GENERAL METHODS: Example B1 10.3 g of diethyl thiodiacetate (product of Example A6) was mixed with 10.96 g of diethyl oxalate (Acros, Belgium) and cooled in a water bath at 0-10 °C. An ethanol solution containing sodium ethanolate (Acros, Belgium) was slowly added dropwise to the mixture with sufficient stirring. Subsequently, the reaction mixture was transferred to a microwave reactor and microwave heated at 100 W power, 2.45 GHz frequency for 60 min, keeping the reaction temperature at 68 °C. Upon completion of the reaction, the pH of the reaction solution was adjusted to 7.0-7.5 with HCl (Scharlau, Australia) to terminate the reaction, followed by removal of ethanol by evaporation. The pH was adjusted to 2.5-3.0 by adding HCl to the dried residue and the product was precipitated by adding 400 mL of deionized water. The precipitate was collected by filtration and dried in an oven to give 8.58 g of diethyl 3,4-dihydroxythiophene-2,5-dicarboxylate in 65.3% yield.

References

[1] RSC Advances, 2015, vol. 5, # 4, p. 2630 - 2639
[2] Patent: EP2548875, 2013, A1. Location in patent: Paragraph 0074-0082
[3] Acta Crystallographica Section C: Crystal Structure Communications, 2004, vol. 60, # 5, p. o338-o340
[4] Journal of Materials Chemistry, 2005, vol. 15, # 45, p. 4783 - 4792
[5] Patent: WO2006/73968, 2006, A2. Location in patent: Page/Page column 22