Synthesis of tetrachloroisophthalic and-terephthalic aldehydes and stable bis(nitrile oxides) based on them

Abstract

A new route for the synthesis of 2,4,5,6-tetrachloroisophthalic and 2,3,5,6-tetrachloroterephthalic aldehydes from the corresponding tetrachlorobenzenes was developed. The method involves dichloromethylation of the initial compounds with chloroform in the presence of aluminum chloride and subsequent hydrolysis of the resulting 1,3-bis(dichloromethyl)-2,4,5,6-tetrachlorobenzene and 1,4-bis(dichloromethyl)-2,3,5,6-tetrachlorobenzene. Stable 2,4,5,6-tetrachlorobenzene-1,3-dicarbonitrile oxide and 2,3,5,6-tetrachlorobenzene-1,4-dicarbonitrile oxide were obtained for the first time from the above aldehydesvia the corresponding oximes. The products were characterized by IR and13C NMR spectra, and were converted into substituted 1,3- and 1,4-phenylenebis(isoxazolines) using 1,3-dipolar cycloaddition with styrene.