PREPARATION OF INTERMEDIATES OF X-RAY CONTRAST AGENTS

摘要

The present invention relates to a process for the preparation of iodinated X-ray contrast agents and in particular to key intermediates thereof. It particularly relates to an improved process for preparation of 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (Compound A) or N,N′-bis(2,3-dihydroxypropyl)-5-formamido-2,4,6-triiodoisophthalamide (Compound C), which are intermediates in the industrial preparation of non-ionic X-ray contrast agents. More particularly the invention provides a process for deacylation of the acylated hydroxyl groups of an intermediate compound of Compound A and Compound C.

主权项

1. A process for preparation of an N-acylated monomeric compound selected from 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (Compound A) and N,N′-bis(2,3-dihydroxypropyl)-5-formamido-2,4,6-triiodoisophthalamide (Compound C) comprising a step wherein Compound B2,wherein each X individually denotes a hydrogen or an acyl group, provided that at least one of the X-groups attached to the nitrogen is an acyl group;is subjected to deacylation of the acylated hydroxyl groups by adding the Compound B2 to an aqueous solution of a deacylating agent.