Study On Synthesis Of 5-arylfuran-2,3-dicarbonitriles And Its Optical Properties

Furan compounds are very common in our daily life, and the compounds containing furan skeleton are not only the core structure of many natural products and the molecular unit of function materials, but also have a variety of biological activities such as antibacterial, anti-inflammatory, anti-allergic, anti-Pneumocystis carinia and anti-tumor. Thus, it has applied widely in medicine, pesticide and biochemistry. In this thesis, we systematically studied the reaction of acetophenone derivatives and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone as the substrate, generating novel furan derivatives via the cyclization reaction. The main contents are as follows.Firstly, the syntheses of the electron-rich aryl ketones were studied, and a series of alkoxyl substituted aryl ketone derivatives were synthesized. The synthetic method for alkoxyl acetophenone derivatives is well-documented, and the yield of the reaction is good. In this thesis,15 acetophenone derivatives were obtained by Friedel-Crafts acylation reaction in a yield of 71%-97%.Secondly, we systematically studied the synthesis of novel 5-arylated 2,3-dicya-nofurans by the reaction of electron-rich aryl ketones with DDQ. With a series of parallel reactions done, the effects of the solvent, the reaction temperature, reaction molar ratio, as well as factors such as the type of catalyst, on the yield were investigated. The optimal conditions for such transformation were established as follows: DDQ/ketone ratio being 3.0, DCE being the best solvent, temperature being 100℃ for 13 h under N2 without any metal catalyst. Under such optimal reaction conditions, we synthesized 14 corresponding 5-arylated 2,3-dicyanofurans in a yield of 25%-62%. The present approach has advantages of milder reaction condition, easier work-up operation and metal-free.This is a novel and efficient method for the synthesis of furan derivatives in one step.The fluorescence properties of novel 5-arylated 2,3-dicyanofurans were investigat-ed by UV-Vis spectra and fluorescence spectra and the relationship between the structures and photophysical properties showed that the greater the concentration, the stronger the fluorescence intensity; different substituents at the same position have an effect on the fluorescence properties; identical substituents in different position also have an impact on the fluorescence properties of the compounds, in which 5-(naphthalen-2-yl)furan-2,3-dicarbonitrile has the strongest fluorescence intensity, its maximum excitation wavelength is 329 nm, and maximum emission wavelength is 400 nm.