The synthesis of 2,4-diarylquinolines is reported by employing arylamine, aryl aldehyde, and aryl acety-lene using 30 mol% p-toluenesulfonic acid monohydrate (p-TSA center dot H2O) as a catalyst at 110 degrees C temperature under solvent-free conditions via a one-pot three-component reaction. The salient features of the present protocol are the nonrequirement of a metal catalyst, additive, solvent, and inert atmospheric reaction conditions, good yield, substrate scope, and shorter reaction time. Using 30 mol% p-toluenesulfonic acid monohydrate (p-TSA center dot H2O) as a catalyst in solvent-free conditions has made the three-component reac-tion efficient enough to form 2,4-diarylquinoline without the involvement of any heavy metal catalyst or additives.(c) 2023 Elsevier Ltd. All rights reserved.