Preparation and Characterization of Substituted 3-Benzothiazol-2-ylcoumarins

A series of substituted 3-benzothiazolylcoumarins was prepared from condensation of 2-hydroxybenzaldehyde and 2-cyanomethylbenzothiazole to investigate the effect of the nature and position of substituents on their absorption and fluorescent behavior Compounds with a substituent containing a heteroatom which attached at the C6 position showed a split broad absorption band Solutions of these compounds in various solvents exhibited brilliant blue fluorescence. The emission intensity for compounds with an alkoxy group at the C6 or C7 position in DMF was approximately 7- and 15-fold higher than for the corresponding precursor and quinine sulfate solution, respectively These compounds also exhibit high thermal stability in solid state.