The Synthesis Of Calix[6]arene Derivatives At The Lower Rim

Calix[n]arene like crown ethers and cyclodextrinx represent an important class of host in supramolecular chemistry,which has two intrinsic feature including molecular recognition and self-assembly.During the past three decades,calix[n]arenes,especially calix[4]arene,have become an very important framework in host-guest chemistry, which have versatile applications in catalyst as well as many other fields.In recent years, calix[6]arene,whose spacer is larger than calix[4]arene,have made more attraction.In order to expand the study and application of calix[6]arene,We initiated the studies concerning the synthesis of calix[6]areen derivates at the lower rim.1.Calix[6]arene was synthesized by condensation from p-tert-phenol and formaldehyde,followed by reverse F-C reaction.Sometimes,the two steps reaction generate mixture consist of similar compounds.To recycle this mixture,we studied and succeed obtained pure calix[6]arene from the mixture.2.The reactions of calix[6]arene and three sulfochlorides(p-toluene sulfonyl chloride,benzene sulfonyl chloride,methane sulfony chloride) were studies,three new compounds were synthesized.They were hexa-tosylate-calix[6]arene, hexa-besilate-calix[6]arene,and penta-mesylate-calix[6]arene.Methylchloroformate is a special acyl chloride,we also studied the reaction methylchloroformate and calix[6]arene,the obtained product was hexa- methylformate-calix[6]arene. 3.Calixarenes containing ester is an important class of compound as intermediate.A study was made on the reaction of calix[6]arene and ethyl bromoacetate,three compounds were obtained.Therein,1,2,3-trisubstitued compound was synthesized in 57.3%yield,which is a new compound not reported by literature.The other two products were 1,4-disubstitued and hexasubstitued compounds.