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

摘要

PCT No. PCT/EP95/04635 Sec. 371 Date May 29, 1997 Sec. 102(e) Date May 29, 1997 PCT Filed Nov. 24, 1995 PCT Pub. No. WO96/16927 PCT Pub. Date Jun. 6, 1996A 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.