ALTERNATIVE ACETYLATION PROCESS IN THE SYNTHESIS OF NON-IONIC X-RAY CONTRAST AGENTS

摘要

An alternative acetylation process for the synthesis of 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (“Compound A”), an intermediate in the industrial preparation of non-ionic X-ray contrast agents, is described. The process can be performed on an industrial scale to produce Compound A with improved purity and improved yields compared to the established processes.

主权项

1. A process comprising the steps of:
(i) reacting 5-amino-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (“Compound B”) with a mixture of acetic anhydride/acetic acid to form a slurry; (ii) heating said slurry to about 60° C.; and (iii) adding an acid catalyst to said slurry at a rate such that the reaction temperature is maintained at a temperature range of about 65-85° C.