Synthesis of novel trans-stilbene derivatives containing a 4H-pyran-4-one unit and spectroscopic studies of two of their malononitrile derivatives

Abstract

New phosphonium salt was synthesized by treatment of 2-(4-bromomethylphenyl)-6-phenyl-4H-pyran-4-one with triphenylphosphine in toluene in 83 % yield. Treatment of phosphonium salt with substituted benzaldehydes such as C6H5–, p-MeC6H4, p-MeOC6H4, p-NO2C6H4, m-NO2C6H4, o-NO2C6H4, p-ClC6H4, o-ClC6H4, p-BrC6H4CHO in the presence of NaOH in CH3CN:H2O (1:1 v:v) afforded corresponding trans-stilbenes in 29–90 % yields. Two malononitrile derivatives were synthesized and their spectroscopic properties were investigated using UV–Vis and fluorescence spectra. The results showed that these compounds exhibited fluorescence emission.