Patent ID: 8835685

Claim:
A process for the preparation of a 5-[(2-hydroxyacyl)amino]-2,4,6-triiodo derivative of general formula (5) or a pharmaceutically acceptable salt thereof: wherein: R is independently in each occurrence a group selected from: —COOR′ and —CON(R′) 2 ; R′ is independently in each occurrence: hydrogen or a linear or branched (C 1 -C 4 ) alkyl group, optionally substituted by one or more hydroxy groups as such or in a protected form thereof; and X is hydrogen or a linear or branched (C 1 -C 4 ) alkyl group; by Smiles rearrangement of a compound of general formula (4) or a salt thereof: wherein: R, R′ and X are as defined above; said rearrangement obtained by contacting compound (4) with an anion exchanger solid phase, in the presence of an aqueous solvent.