Efficient Synthesis of Highly Substituted N‐Arylamino quinolone‐based Pyrrolo[3,4‐b]pyridines and Pyrazolone‐based Pyrrolo[3,4‐b]pyridines Through a One‐Pot Three‐Component Reaction

Abstract

AbstractIn this research, a simple and efficient strategy for the straightforward synthesis of multisubstituted N‐arylamino quinolone‐based pyrrolo[3,4‐b]pyridine derivatives and pyrazolone‐based pyrrolo[3,4‐b]pyridine derivatives is presented by a sequential three‐component reaction of α‐aminomaleimides, 2‐chloroquinoline‐3‐carbaldehyde/5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde and malononitrile/ethyl 2‐cyanoacetate as readily available starting materials in EtOH at room temperature. The merit of this sequential Michael addition/intramolecular cyclization is highlighted by its high energy conserving (short reaction times at room temperature) excellent yields, metal‐free catalyst, and green and mild conditions in a one‐pot reaction. With this synthesis, group‐assistant‐purification (GAP) chemistry can be simplified by eliminating chromatography and recrystallization, and the pure products can be obtained by washing the crude products with 95 % ethanol. Their structures were characterized by spectroscopic data IR, MS, 1H, and 13C NMR analysis.