Sodium Hydroxide → thiophene-2,3-dicarboxylic acid

HRID 1465961Notes

Reaction equation

HRID 1465961 reaction equation
[CH3:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:7]([OH:9])=[O:8].[O-:10][Mn](=O)(=O)=O.[K+].[OH-:16].[Na+]>>[S:4]1[CH:5]=[CH:6][C:2]([C:1]([OH:10])=[O:16])=[C:3]1[C:7]([OH:9])=[O:8]

Participants

4

Reactant 3

HCID 14798Sodium HydroxideHCID 902693-Methyl-2-thenoic acidHCID 516875Potassium Permanganate3×

Product 1

HCID 255852thiophene-2,3-dicarboxylic acid

Procedure

A solution of 3-Methyl-thiophene-2-carboxylic acid (0.5 mol; 71.09 g) in aqueous 15% NaOH (2300 ml) was heated to 75-80° C. before KMnO4 (0.42 mol; 67.05 g) was added with stirring. After stirring at 75-80° C. for 30 min another portion of KMnO4 (0.42 mol; 67.05 g) was added. This was repeated another three times. After adding the last portion of KMnO4, stirring was continued at 75-80° C. for 30 min before the mixture was refluxed for 3 h with stirring. The hot mixture was submitted to vacuum filtration and the filtrate was acidified by addition on conc. aqueous HCl. The formed precipitate was separated, washed with water and dried in vacuo at 80° C. to give the title compound as a slightly yellowish solid (43.9 g). 1H NMR (d6-DMSO, 200 MHz): δ=7.78 (d, 1H), 7.37 (d, 1H).

Workup

  1. additionwas added
  2. additionwas added
  3. stirringstirring
  4. temperaturewas refluxed for 3 h
  5. stirringwith stirring
  6. filtrationThe hot mixture was submitted to vacuum filtration
  7. additionthe filtrate was acidified by addition on conc. aqueous HCl
  8. customThe formed precipitate was separated
  9. washwashed with water
  10. customdried in vacuo at 80° C.

Sources & evidence

ORD record
ord-e35df5cfa933436c9818eaaa620d4b9e
Source dataset
uspto-grants-2015_04
Patent number
US09000006B2

Reaction notes

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