Ethanol → 3,4-Dihydroxythiophene-2,5-dicarboxylic acid

HRID 984761

Reaction equation

HRID 984761 reaction equation
CCO.[C:4]([C:9]1[S:10][C:11]([C:16]([O:18]CC)=[O:17])=[C:12]([OH:15])[C:13]=1[OH:14])([O:6]CC)=[O:5].[OH-].[Na+]>O>[C:16]([C:11]1[S:10][C:9]([C:4]([OH:6])=[O:5])=[C:13]([OH:14])[C:12]=1[OH:15])([OH:18])=[O:17]

Participants

5

Reactant 3

HCID 702Ethanol2×HCID 14798Sodium HydroxideHCID 2455033,4-Dihydroxy-thiophene-2,5-dicarboxylic acid diethyl ester

Product 1

HCID 3162693,4-Dihydroxythiophene-2,5-dicarboxylic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

EtOH (30 mL) was added to 2,5-dicarbethoxy-3,4-dihydroxythiophene (1 g). A solution of NaOH (4.0 g) in H2O (20 mL) was added and refluxed under N for 20 h. Upon cooling to ambient temperature the EtOH was removed by distillation and the residue was redissolved in H2O then acidified with 15% HClaq when a white ppt was obtained This product was collected by filtration and washed with cold H2O then crystallized from dilute MeOH to give colorless needles.

Workup

  1. temperaturerefluxed under N for 20 h
  2. customwas removed by distillation
  3. dissolutionthe residue was redissolved in H2O
  4. customwas obtained This product
  5. filtrationwas collected by filtration
  6. washwashed with cold H2O
  7. customthen crystallized from dilute MeOH
  8. customto give colorless needles

Sources & evidence

ORD record
ord-0e1c8a71196d4753a61e5b592f8c8adb
Source dataset
uspto-grants-2005_03
Patent number
US06869729B1

Linked notes

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