The Design,Preparation And Application Of Swern Reagent And The Synthetic Process Of 1,3-Dichloro-5-Nitrobenzene

Swern oxidation is one of the most efficient methods in the oxidation of alcohols to afford the corresponding aldehydes or ketones,but its application is limited due to the harsh reaction condition.In this article,a new type of sulfoxide was designed and prepared in good yield on the basis of the reported methods to replace DMSO as another improvement of Swern oxidation.Another part of this article is about the research in the synthetic process of 1,3-dichloro-5-nitrobenzene.1,3-Dichloro-5-nitrobenzene is an important medicinal and chemical intermediate,but the synthetic process reported at present can cause the environment pollution.In this article,some research in the synthesis of 1,3-dichloro-5-nitrobenzene had been developed and the optimum reaction condition is provided,which may be technically useful for the application of production.The research progress of Swern oxidation and some comments on the literature were introduced in the first chapter.In the second chapter,the design and synthetic procedures of new types of sulfoxide were presented in detail until 4-(2-(2-(methylsulfinyl)ethyl)-4-nitrophenyl) morpholine(I) was prepared in good yield.Upon the combination of I and bis(trichloromethyl)carbonate(BTC),the Swern oxidation of primary and secondary alcohols was significantly promoted under mild condition.We also screened the optimized condition towards the loading of I and BTC at various temperatures to give-15 ~oC as the optimum reaction temperature and the ratio of alcohol,sulfoxide I and BTC was recognized as 1:1.5:0.5.The scope of this new oxidation method was studied under the optimum condition.We put forward a probable mechanism which was tested by some experiments.Our method needs low energy and avoids the formation of the stinking byproduct methyl-(phenethyl)-sulfane and the toxic carbon monoxide.The byproduct sulfide V derived from sulfoxide I is odorless and can be easily isolated,re-oxidized and reused,which is in conformity with the principles of friendly synthesis and green chemistry.In the third chapter,the application and the research progress in the synthetic process of1,3-dichloro-5-nitrobenzene were introduced.On the basis of the previous research work about diazotization deamination reaction in our group,the synthesis of 1,3-dichloro-5-nitrobenzene has been studied further in the fourth chapter,in which the solvents,the amount and concentration of t-BuONO,and the reaction time were studied.We choose THF as the optimum solvent,and the ratio of 2,6-dichloro-4-nitroaniline,t-BuONO,THF was recognized as 1:1.6:3.2 at 30~oC.This process is environmentally friendly and the cost may reduce because of the lower energy,the less amount and recovery of solvent compared to other reported processes.So it may have potential in industrial production.