A general and convenient practical approach for the synthesis of polyhydroquinoline derivatives has been achieved via one-pot four-component Hantzsch condensation of aromatic aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of a catalytic amount of gallium (III) chloride, in ethanol solvent at ambient temperature. The UV-Visible and photoluminescence (PL) spectra of Ethyl-1,4,7,8-tetrahydro-2,7,7-trimethyl-4-(4-chlorophenyl)-5(6H)- oxoquinolin-3-carboxylate is also reported. The interaction of synthesized compound and salicylic acid was studied by using steady state emission spectroscopy. The fluorescence quenching of salicylic acid showed red shift with increasing concentration of polyhydroquinolines (acceptor) is in accordance with Stern–Volmer relation. The quenching rate constant 3.8x10-6M-1S-1 was obtained from the fluorescence lifetime of salicylic acid measured on time resolved fluorimeter (TRF) in absence of polyhydroquinolines.