Synthesis Of Benzamides/Benzoxazoles And Benzoxazolidines

In this paper,a series of studies on the coupling/cyclization of o-aminophenol and diphenoyl were carried out.Three kinds of compounds were synthesized by three different synthetic routes,including benzamide and its derivatives,benzoxonium oxazole and its derivatives,and benzoxazolidine and its derivatives.The main research contents are divided into the following three parts:1.The synthesis of benzamide was achieved by coupling with o-aminophenol and biphenyl formyl.The reaction consisted of 21 benzoa mides,which consisted of substituted o-aminophenol and substituted biphenylcarboxyl as raw materials and two-step reaction "one-pot".First,under the conditions of trifluoroacetic acid cyclization dehydration to produce the halogenated benzoxazine interm ediates,and then continue to add strong base in the system so that the intermediate dehydrogenation,in the air under the oxygen induced free radical reaction,Induced chemical bonds break,and then enolate alternately formed benzamide compounds.2.The synthesis of benzoxazole was achieved by cyclization with o-aminophenol and biphenyl.In this reaction,a five-membered transition state compound was formed under basic conditions using substituted o-aminophenol and substituted biphenyl formyl as raw materials to study the synthesis of benzoxazoles and to investigate the effect of different substituents,14 benzoxazoles with different substituents were synthesized.3.The synthesis of benzoxazolidine was achieved by cyclization with o-aminophenol and biphenyl.At present,there are few studies on these compounds at home and abroad,and the two carbonyl groups of Biphenyl benzoyl are activated simultaneously by the complexation of copper trifluoromethanesulfonate,and the transition state is formed with o-aminophenol,And then under the conditions of weak acid re-generated benzoxazolidine compounds.And 10 novel benzoxazolidine derivatives were synthesized by studying the universality of the substrate.4.In this paper,we completed the above three parts,the synthesis of benzamide,benzoxazole and benzoxazolidine three kinds of compounds.The three types of compounds are insect-resistant,antibacterial,anti-cancer and other important biological activity.On the basis of previous studies,we have opened up new ways and methods of synthesis for these three kinds of compounds.