Hydrochloric Acid → 3,4-Dihydroxy-thiophene-2,5-dicarboxylic acid diethyl ester

HRID 984760

Reaction equation

HRID 984760 reaction equation
[C:1](OCC)(=[O:7])[C:2](OCC)=[O:3].[CH2:11]([O:13][C:14](=[O:21])[CH2:15][S:16][CH2:17][C:18]([O-:20])=[O:19])[CH3:12].O.Cl.[CH3:24][CH2:25]O>>[C:18]([C:17]1[S:16][C:15]([C:14]([O:13][CH2:11][CH3:12])=[O:21])=[C:1]([OH:7])[C:2]=1[OH:3])([O:20][CH2:24][CH3:25])=[O:19]

Participants

6

Reactant 5

HCID 313Hydrochloric AcidHCID 702EthanolHCID 962WaterHCID 7268Diethyl OxalateHCID 86604148Thiobisacetate ethyl ester

Product 1

HCID 2455033,4-Dihydroxy-thiophene-2,5-dicarboxylic acid diethyl ester

Procedure

Diethyl oxalate (6.58 g. 45 mmol) was added to 2.2° thiobisacetate ethyl ester (4.66 g. 23 mmol) to produce a yellow-orange solution. A solution of Na (1.56 g, 68 mmol) in EtOH (24 mL) was added to produce a white/yellow precipitate, this was mixed well for 10 minutes. H2O (50 mL) was added to the reaction mass with cooling in an ice bath. Concentrated HCl was added dropwise until acidified. This was allowed to stand in the refrigerator for 12 days. At this point a cold filtration was done to isolate a white solid.

Workup

  1. customto produce a yellow-orange solution
  2. customto produce a white/yellow precipitate
  3. additionthis was mixed well for 10 minutes
  4. temperaturewith cooling in an ice bath
  5. filtrationAt this point a cold filtration
  6. customto isolate a white solid

Sources & evidence

ORD record
ord-51a03ac9c6464e8e91808ce3614aae87
Source dataset
uspto-grants-2005_03
Patent number
US06869729B1

Linked notes

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