31891-06-2

40018-26-6

105-56-6

31891-06-2

The general procedure for the synthesis of ethyl 2-aminothiophene-3-carboxylate from 1,4-dithio-2,5-diol and ethyl cyanoacetate was as follows: in a 2-5 mL microwave reaction flask, ethyl cyanoacetate (0.22 mmol, 1.0 equiv.) and trifluoroethanol (2 mL) were added, and stirred for 2 min until complete dissolution. Subsequently, 1,4-dithio-2,5-diol (0.11 mmol, 0.5 eq.) was added and stirring was continued for 5 min. Next, triethylamine (0.242 mmol, 1.1 eq.) was added and the reaction mixture was stirred for another 2 minutes. The reaction flask was sealed and placed in a microwave reactor and heated at 60 °C for 390 min. After completion of the reaction, the solvent was removed by vacuum evaporation. The crude product was purified by silica gel fast column chromatography (eluent: ethyl acetate/hexane mixed solvent) to afford the target product ethyl 2-aminothiophene-3-carboxylate.