Synthesis and Florescent Properties of 5-Aryl-3-(3-coumarinyl)-1-benzothiazolyl-2-pyrazolines

A series of novel 5-Aryl-3-(3-coumarinyl)-1-benzothiazolyl-2-pyrazolines have been synthesized by the reaction of 3-coumarinyl chalcones with 2-hydrazinobenzothiazole in hot ethanol. And the structures of these new compounds have been characterized by (HNMR)-H-1, MS and elemental analysis. The fluorescence spectra of these compounds were also measured. All the compounds showed up strong green light emissions (lambda em: 557-570nm). The results showed that the absorption maxima of the compound vary from 415 to 420nm depending on the group bonded to pyrazolines rings.