Study On The Synthesis And Fluorescence Properties Of The New Pyrazoles And Pyrazolines

In this paper, L-proline-catalyzed Aldol condensation reaction of N-methyl and N-benzyl-4-Hydroxy-3-acetyl-2(1H)-quinolinones with different aromatic aldehydes has been developed, which afforded a series of chalcone analogues. Cycloaddition reaction of chalcone analogues with hydrazine hydrate and phenyl hydrazine has been performed subsequently, which gave a series of new pyrazoline containing 4-Hydroxy-2(1H)-quinolinone unit. Oxidation of pyrazolines using MnO2 to produce corresponding pyrazoles derivatives. All of the new compounds were characterized and conformed by IR,1H NMR, MS.The optical properties of some products, such as ultraviolet-visible spectrum and fluorescent spectrum were investigated. It was shown that the kinds of monomers had stronger fluorescence properties, the emitted wavelength of the monomers are about 620nm, 600nm.The optimum reaction conditions were obtained from the experiment. The yields of pyrazolines analogues were 84%-96% when the mole ratio of hydrazine hydrate and chalcone analogues was 3:1, the mole ratio of phenyl hydrazine and chalcone analogues was 2:1, reaction temperature was 100℃, reaction time was 12h. The yields of pyrazoles derivatives were 80%～86% when the mole ratio of MnO2 and pyrazolines analogues was 8:1, reaction temperature was under 30℃, reaction time was 48h.