Abstract
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%.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (Grants 20472094, 20372069, 20102007, and 29725203), the Qi Ming Xing Foundation of Shanghai Ministry of Science and Technology (Grant 03QD14065), and the 863 Hi‐Tech Program of China (Grants 2003AA235030, 2002AA233061).