SYNTHESIS OF TETRACHLOROISOPHTHALIC AND TETRACHLOROTEREPHTHALIC ALDEHYDES AND STABLE BIS(NITRILE OXIDES) BASED ON THEM

A new route for the synthesis of 2,4,5,6-tetrachloroisophthalic and 2, 3,5,6-tetrachloroterephthalic aldehydes from the corresponding tetrach lorobenzenes was developed. The method involves dichloromethylation of the initial compounds with chloroform in the presence of aluminum chl oride and subsequent hydrolysis of the resulting 1.3-bis(dichloromethy l)-2,4,5,6-tetrachlorobenzene and ,4-bis(dichloromethyl)-2,3,5,6-tetra chlorobenzene. Stable 2,4,5,6-tetrachlorobenzene-1,3-dicarbonitrile ox ide and 2,3,5,6-tetrachlorobenzene-1,4-dicarbonitrile oxide were obtai ned for the first time from the above aldehydes via the corresponding oximes. The products were characterized by IR and C-13 NMR spectra, an d were converted into substituted 1,3- and 1,4-phenylenebis(isoxazolin es) using 1,3-dipolar cycloaddition with styrene.