D-pi-A type red fluorescence labeled chitosan as well as preparation method and application thereof

The invention provides D-pi-A type red fluorescence labeled chitosan as well as a preparation method and application thereof, and belongs to the technical field of medical intermediates and material chemistry, 2, 3-diamino fluorobenzene is taken as a raw material, condensation with selenium dioxide is performed to obtain a selenadiazole intermediate, further nitration is performed to obtain a fluorescent agent precursor SeFN, and the fluorescent agent precursor SeFN is subjected to post-treatment to obtain the D-pi-A type red fluorescence labeled chitosan. And finally, carrying out nucleophilic substitution reaction with amino groups of chitosan to obtain the red fluorescence labeled chitosan. The preparation method is simple and easy to implement, the product yield is high, separation and purification are easy, and the prepared red fluorescence labeled chitosan can be used in the fields of biological imaging and the like. 本发明提供了一种D-π-A型红色荧光标记的壳聚糖及其制备方法和应用，属于医药中间体领域和材料化学技术领域，以2,3-二氨基氟苯为原料，通过与二氧化硒缩合得到硒二唑中间体，进一