Study On Synthesis And Fluorescence Properties Of Indolylmaleimide Hetero-Cycle Derivatives

Indolylamaleimide is a family of pigments produced from Streptomyces, including Staurosporine. Taking advantage of their remarkable biologically active and novel structure, consequently, many derivatives of the parent indolylamaleimides structure had been synthesized and tested to explore as a lead structure. Recently years, the research conducted on indolymaleimide derivatives have two goals. In the pharmaceutical area, some of these derivatives are selective inhibitors of protein kinase(PKC) can show promising therapy agents for changing microcirculation. In the area of photonic functional materials application, indolylmaleimide compounds have a strong conjugated structer and bisindolylmaleimides yielded bright red luminescenc-e both in solutions and in the solid state. Especially recently, bisindolylmaleimides were successful applied in the red-emitting light emitting diodes (LEDs). Researcher caused great interest for this class of compounds. This article summarizes the research progressed on indolylmaleimide compounds. On the base of the research, twelve compounds were designed, synthesized and evaluated for their ultraviolet and fluorescent properties. The main contents of this paper are as follows:1. Bisindolylmaleimides were synthesized from succiminide by bromination and indole addition in the prescence of magnesium and ethyl bromide.3,4-bis (1H-indole-3-yl)-1-amino-1H-pyrrole-2,5-dione and by-product 2,3-bis(indol-3-yl) succinohydrazide were made by hydrazine reaction, connection with amino as activity site, respectively 72% and 82%.2. Four novel N-benzamidobisindolylmaleimide derivatives and a N-acetamidebi-sindolylmaleimide were synthesized from 3,4-bis(1H-indole-3-yl)-1-amino-1H-pyrro- le-2,5-dione, via acetylation with acyl chlorides. T04 and T05 were synthesized from N-Benzamidobisindolylmaleimide by alkylation. They were not reported in the literature. Their structures had been confirmed by IR,1H NMR, ESI-MS and HRMS techniques.3. The ultraviolet and fluorescence spectra of the target compounds T01, T02, T03, T04, T05 show that theλabs ranged from 360 to 400 nm and from 450 to 500 nm, and the maximumλem ranged from 560 to 620 nm, which show that these compounds have good fluorescence with strong fluorescence intensity. When the methyl and benzyl group was introduced into T04 and T05, the fluorescent emission wavelength took place Einstein shift. Using Rhoda Mine B as a reference, the fluorescence quantum yields were all tested, and T04 has the largest fluorescence quantum yield. The fluorescence quantum yields of representative T04 in different solvents at maximum excitation wavelength were also measured and the results showed that the polarity of the solvents hardly had any relation to the fluorescence quantum yields of the target compounds. Thermal behavior of the compounds T04 and T05 had been investigated by DSC and TGA. Glass-transition temperature(Tg) of T04 and T05 appeared at 80℃and 116℃, respectively. The high thermal stability was confirmed by TGA experiments. No sign of decomposition appeared upon heating below 400℃.4.3-bromo-4-(1-methylindole-3-yl)-1H-pyrrole-2,5-dione was prepared from 3,4-dibromo-1H-pyrrole-2,5-dione by indole addition, alkylation, and so on.3-bromo-4-(1-methylindole-3-yl)-1-methylpyrrole-2,5-dione was synthesized by further alkylation with methyl iodide. They were reacted with substituted aminothiophenols to provide five 1H-pyrrolo[3,2-b][1,4] benzothiazine -2-one derivatives. All of the compounds were not reported in the literature. Their structures had been identified by IR,1H NMR, ESI-MS and HRMS techniques.