Process for preparing 5-amino-2,4,6-triiodoisophthalic acid dichloride by chlorination of the corresponding acid in the presence of a tertiary amine salt or quaternary ammonium salt

摘要

A process for the preparation of 5-amino-2,4,6- triiodoisophthalic acid dichloride by chlorinating 5-amino-2,4,6- triiodoisophthalic acid with thionyl chloride in the presence of a suitable solvent and of a tertiary amine salt or quaternary ammonium salt in a molar ratio from 1; 1 to 1;2 with respect to 5-amino-2,4,6- triiodoisophathalic acid is described. 5- amino-2,4,6-triiodoisophthalic acid dichloride is an intermediate useful for the preparation of iodinated contrast agents.