One‐Pot Three‐Component Synthesis of Pyrido[2,3‐c]carbazole Derivatives in EtOH under Catalyst‐Free Conditions

A three‐component reaction of aromatic aldehydes, 9‐ethyl‐9H‐carbazol‐3‐amine, and cyclopentane‐1,3‐dione or tetronic acid was carried out in EtOH at refluxing and gave two series of 2,3,7,12‐tetrahydrocyclopenta5,6]pyrido2,3‐c ]carbazol‐1(4H )‐one and 3,4,7,12‐tetrahydro‐1H‐furo3′,4′:5,6]pyrido2,3‐c ]carbazol‐1‐one derivatives, respectively. This procedure approach to pyrido2,3‐c ]carbazoles has the advantages of milder reaction conditions, one‐pot, catalyst free, and high yields.