Sodium Hydroxide → 2-amino-4,5-dimethylthiophene-3-carboxylic acid

HRID 1973411Notes

Reaction equation

HRID 1973411 reaction equation
[NH2:1][C:2]1[S:3][C:4]([CH3:13])=[C:5]([CH3:12])[C:6]=1[C:7]([O:9]CC)=[O:8].[OH-].[Na+]>C(O)C.O.C(O)(=O)C>[NH2:1][C:2]1[S:3][C:4]([CH3:13])=[C:5]([CH3:12])[C:6]=1[C:7]([OH:9])=[O:8]

Participants

6

Reactant 2

HCID 14798Sodium HydroxideHCID 78536Ethyl 2-amino-4,5-dimethyl3-thenoate

Product 1

HCID 37266372-amino-4,5-dimethylthiophene-3-carboxylic acid

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 702EthanolSolventHCID 962WaterSolvent

Procedure

A mixture of 15 parts of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate and 75 parts by volume of 2N solution of sodium hydroxide in 50% aqueous ethanol is refluxed for 2.5 hours. After cooling the solution is diluted with 75 parts by volume of water and neutralized with acetic acid under cooling with ice. The resulting precipitate is collected by filtration to give 2-amino-4,5-dimethylthiophene-3-carboxylic acid as crystals. Recrystallization from chloroform with charcoal gives colorless needles melting at 136°-138° C (decomposition).

Workup

  1. temperatureis refluxed for 2.5 hours
  2. temperatureAfter cooling the solution
  3. temperatureunder cooling with ice
  4. filtrationThe resulting precipitate is collected by filtration

Sources & evidence

ORD record
ord-6688fa80f3c548d984986a4d1100f606
Source dataset
uspto-grants-1976_12
Patent number
US03997545

Reaction notes

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