A Green Synthesis of 2-Amino-4-(9H-carbazole-3-yl)thiophene-3-carbonitriles by a Step-wise and One-pot Three-component Gewald Reaction

作者：Avula Vijay Kumar Reddy; Vallela Swetha; Anireddy Jaya Shree; Chamarthi Naga Raju^*

来源：Journal of Heterocyclic Chemistry, 2017, 54(4): 2471-2482.

DOI：10.1002/jhet.2847

An eco-friendly method has been developed for the synthesis of 2-amino-4-(9H-carbazole-3-yl)thiophene-3-carbonitriles from preliminary carbazole (1) through an intermediate of 2-(1-(9H-carbazole-3-yl)ethylidene)malononitriles using the Knoevenagel condensation followed by the Gewald reaction. On the other hand, the target compounds could also be prepared in a one-pot three-component manner by treating equimolar quantities of 1-(9H-carbazole-3-yl)ethanone (3), malononitrile, and elemental sulfur. The merits of this preparation are mild reaction conditions. The Gewald reaction is executed with inorganic base NaHCO3 (H2O) in tetrahydrofuran, easy work-up procedure with good yields.

• 出版日期2017-7