The facile preparation of p-(methoxy)calix[n]arenes (n=6, 7, or 8) and their permethylated derivatives

The mixture of p-(methoxy)calix[n]arenes (n = 6, 7 or 8) was prepared in one step from p-methoxyphenol under basic conditions, and their fully methylated derivatives p-(dimethyloxy)calix[n]arenes (n = 6, 7 or 8) were also prepared and purified by column chromatography to indentify their structures. In this process, the single crystal of p-(dimethyloxy)calix[7]arene was obtained and its structure was confirmed. The proportion of p-(methoxy)calix[6]-, [7]- and [8]-arenes in the mixture obtained from the reaction was investigated under different reaction conditions, and p-(methoxy)calix[6]- and [8]-arenes could be separated from the mixture by solvent extraction. In addition, the host-guest interaction of p(dimethyloxy)calix[6]arene with methyl-4,4'-bipyridinium hexafluorophosphate in organic solvents was investigated. (C) 2021 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

The mixture of p-(methoxy)calix[n]arenes was prepared in one step under basic conditions, and their fully methylated derivatives were also obtained and purified. The single crystal of p-(dimethyloxy)calix[7]arene was successfully obtained and its structure confirmed. Different reaction conditions were investigated to determine the proportion of p-(methoxy)calix[6]-, [7]- and [8]-arenes in the mixture, with the ability to separate p-(methoxy)calix[6]- and [8]-arenes. Additionally, the host-guest interaction of p(dimethyloxy)calix[6]arene with methyl-4,4'-bipyridinium hexafluorophosphate in organic solvents was studied.