Microwave-assisted synthesis of 2-amino-thiophene-3-carboxylic derivatives under solvent-free conditions

Under microwave irradiation and solvent-free conditions, cyanoacetates (cyanoacetamides) react with ketones and sulphur in the presence of a small amount of morpholine to give 2-amino-thiophene-3-carboxylic derivatives. In particular, tetrahydro-benzo[b]thiophene-3-carboxylic acid N-aryl amides were synthesized in high yields of 84-95%.