Tetrazole 5-Acetic Acid Catalyzed Synthesis and Photophysical Study of 2-Aryl-2,3-dihydroquinolin-4(1H)-ones

1H-Tetrazole 5-acetic acid (TAA) has been explored as a new organocatalyst for the synthesis of 2-aryl-2,3-dihydroquinolin-4(1H)-ones derivatives from 2'-aminoacetophenone under solvent-free conditions. The method described herein is covenient and the catalyst could be reused. Mechanistic study of the reaction revealed that the reaction passing through initial activation of the aldehyde by the catalyst and the C-C bond formed through the intermolecular pathway. The synthesized compounds exhibit yellowish-white fluorescence when exposed to 350 nm UV light. Optical properties such as absorption and fluorescence emission spectra were monitored in methanol. Fluorescence emission properties in different solvents with different polarity indicate solvatochromic characteristics of the probes.