Synthesis of Novel 1<i>H</i>‐Imidazol[1,2‐a]Indeno[2,1‐e]Pyridine‐6(5<i>H</i>)‐Ones Derivatives via a One‐Pot Four‐Component Condensation Reaction

Abstract

1 H ‐imidazol[1,2‐a]indeno[2,1‐e]pyridine‐6(5 H )‐ones derivatives were synthesized in a one‐pot four‐component condensation of corresponding aldehydes, 1,3‐indandione, diamine, and nitro ketene dithioacetal using KAl(SO 4 ) 2 ·12H 2 O (alum) as nontoxic, reusable, inexpensive and easily available catalyst in good to excellent yields. This green protocol provides a powerful entry into fused polycyclic structures related to bioactive heterocycles.