Hydrochloric Acid → 3-Amino-2-thiophenecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence