| abstract |
The 4,2'-disubstituted diphenyl carbonate or, optionally, ether content of regioimpure mixtures of compounds of formula: ##STR1## where X is F, Cl, and NO 2 , can be decreased to essentially zero starting with o-, m- and p-containing regioimpure mixtures by treating with the corresponding m- or p-substituted phenol and, optionally, a decarboxylation catalyst and removing the o-substituted phenol produced by volatilization or recrystallization from a solvent. |