60166-97-4Relevant articles and documents
IODINATION PROCESS FOR THE PREPARATION OF 3,5-DISUBSTITUTED-2,4,6-TRIIODO AROMATIC AMINES COMPOUNDS
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Page/Page column 14, (2013/05/22)
The invention discloses a improved process for the preparation of 3,5-disubstituted- 2,4,6-triiodo aromatic amines of formula (II), wherein R1 and R2 are defined as herein. The compounds of formula (II) are the key intermediates for the synthesis of a series of non-ionic contrast agents such as Iopamidol, Iohexol and Iodixanol. The process comprises reacting chlorine-free iodinating reagents with 3,5-disubstituted-2,4,6-triiodo aromatic amines to obtain 3,5-disubstituted-2,4,6-triiodo aromatic amines of formula (II), wherein the molar yield of the iodination reaction can reach to 89%.