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

In 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, 2chloroquinoline-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-assistantpurification (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, 1 H, and 13 C NMR analysis.