Study On Synthetic Process And Application Of 2,4-Dimethylpyrrole And Its Derivatives

As a key building block of many natural products,pyrrole and its derivatives are synthesized by a variety of effective synthesis methods.There are some classic methods: Knorr method,multi-component method,cycloaddition method,and catalysis of transition metal ligand compounds.Among pyrrole and its many derivatives,2,4-dimethylpyrrole and its derivatives are used as crucial intermediates for the synthesis of fluoroborofluoride and many other drugs,and their synthetic methods have attracted much attention,however,these preparation methods are confined to a small scale in the laboratory and cannot be produced on a large scale.Thus,the route and conditions of industrial synthesis need to be further explored.As an important fluorescent dye,the attention of fluorofluorin was attracted by many researchers in the past two decades.Fluorofluorinated fluorescent molecules exhibit excellent photophysical and chemical properties in all kinds of research fields,such as narrower UV-visible absorption spectrum and fluorescent emission spectrum,higher molar absorption coefficient and fluorescent quantum yield,and higher Thermal stability and chemical stability,easy modification of chemical structure,etc.In the aspect of applied research,fluorinated boron fluoride has a wide range of applications in chemical sensing,biological imaging,and solar cells.However,2,4-Dimethylpyrrole and its derivatives are used as a significant intermediate in the synthesis of fluoroboron fluorescent dyes.The exploration of the synthetic method is of great significance for the synthesis of fluoroboron fluorescent.According to the above analysis,the classic Knorr method was used to synthesize 2,4-dimethylpyrrole and its derivatives after comparing the synthetic methods of 2,4-dimethylpyrrole and its derivatives.What's more,the study on processes was explored.At the same time,experiments on a large scale was attempted.2,4-dimethylpyrrole and its derivatives were used to construct the fluorofluorinated molecule and study its basic photophysical properties.This thesis consists of the following two parts:1.The Knorr method was used to construct three kinds of pyrrole derivatives(3,5-dimethyl-2,4-dipyrrolecarboxylic acid ethyl ester,3,5-dimethyl-4-acetyl-2-pyrrolecarboxylic acid ethyl ester,3,5-dimethyl-2-pyrrolecarboxylic acid ethyl ester),the construction conditions were explored from the amount of zinc powder and thereaction temperature,respectively.On the basis of small-scale experiments,an industrial production route has been established through continuous optimization,and a scale-up reaction of 300 g has been achieved.In addition,the post-treatment method about 2,4-dimethylpyrroles and their derivatives(2,4-dimethyl-3-acetylpyrrole,2,4-dimethyl-3-ethylpyrrole,2,4-dimethyl-3-pyrrolecarboxylic acid ethyl ester)has been optimized,which is conducive to the realization of industrial synthesis.2.The applications of 2,4-dimethylpyrrole and its derivatives were studied.Based on the four pyrrole derivatives synthesized in the second part,six kinds of fluorofluorofluoride were synthesized with 2-pyridinaldehyde and p-methoxybenzal dehyde,respectively,and their photophysical properties were systematically study.