Hydrochloric Acid → 3-Amino-2-thiophenecarboxylic acid

HRID 2378094Notes

Reaction equation

HRID 2378094 reaction equation
[OH-].[Na+].[NH2:3][C:4]1[CH:8]=[CH:7][S:6][C:5]=1[C:9]([O-:11])=[O:10].Cl>CO>[NH2:3][C:4]1[CH:8]=[CH:7][S:6][C:5]=1[C:9]([OH:11])=[O:10]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 22256629HCID 22256629, compound

Product 1

HCID 15124973-Amino-2-thiophenecarboxylic acidYield 82%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
60 °C

Procedure

Add 5 N NaOH (50 ml) to a solution of metlhyl 3-aminothiophene-2-carboxylate (7.86, 50.0 mmole) in methanol (250 ml). Heat the reaction mixture at 60° C. overnight. Adjust the pH to about 6 to 7 by adding 1 N HCl. Extract with ethyl acetate (5×200 ml). Combine the organic layers, dry over Na2SO4. Filter and concentrate to provide 3-amino-thiophene-2-carboxylic acid (5.84 g, 82%) as a white powder, which was used immediately for the next step. MS (ES+): 144 (M+H); (ES−): 142 (M−H).

Workup

  1. extractionExtract with ethyl acetate (5×200 ml)
  2. dry with materialCombine the organic layers, dry over Na2SO4
  3. filtrationFilter
  4. concentrationconcentrate

Sources & evidence

ORD record
ord-faa43355bde84261ba6b73bb635a8c50
Source dataset
uspto-grants-2008_12
Patent number
US07470705B2

Reaction notes

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