]quinoline derivatives from aromatic anilines, salicylaldehydes, and cinnamaldehydes under (±)-camphorsulfonic acid catalysis. The optimised protocol offers significant potential for atom economy under mild conditions over the pre-existing multistep approaches. This method is operationally simple and well compatible with a wide range of substrates, with most derivatives forming a precipitate in the reaction mixture. This new approach is followed to perform gram-scale synthesis, achieve smooth results, and demonstrate its industrial applicability. Moreover, chromeno-quinoline frameworks have demonstrated significant potential as pharmacophores and functional materials. The aggregation behaviour of one of the compounds, 4o, was also studied in a THF/hexane solvent, along with concentration-dependent fluorescence spectroscopy. Absolute quantum yield was also measured in both THF and hexane.
Kumar et al. (2026) studied this question.