Abstract: The invention is related to a process for preparing a iodinating X-rays contrast agent. More specifically, it relates to a process for the preparation of N,N?-bis-(2,3-dihydroxypropyl)-5-hydroxy-2,4,6-triiodo-1,3-benzenedicarboxaniide (I) by electrochemical iodination of N,N?-(2,3-dihydroxypropyl)-5-hydroxy-1,3-benzenedicarboxamide (II) with molecular iodine (I2) which is in situ electrochemically generated from a source of iodide ions (I?). The iodide ions (I?) are obtained by the dissolution of hydrogen iodide (HI) or an alkali metal iodide in the reaction medium or produced during the reaction of N,N?-(2,3-dihydroxypropyl)-5-hydroxy-1,3-benzenedicarboxamide with I2. The invention also relates to the use of the intermediate compound of formula (I), obtained through the above electrochemical iodination of compound (II), in the preparation of N,N?-bis[2,3-dihydroxypropyl]-5(hydroxyacetyl)methylamino]-2,4,6-triiodo-1,3-benzenedicarboxamide (iomeprol).

Abstract: The invention is related to a process for preparing a iodinating X-rays contrast agent. More specifically, it relates to a process for the preparation of N,N?-bis-(2,3-dihydroxypropyl)-5-hydroxy-2,4,6-triiodo-1,3-benzenedicarboxaniide (I) by electrochemical iodination of N,N?-(2,3-dihydroxypropyl)-5-hydroxy-1,3-benzenedicarboxamide (II) with molecular iodine (I2) which is in situ electrochemically generated from a source of iodide ions (I?). The iodide ions (I?) are obtained by the dissolution of hydrogen iodide (HI) or an alkali metal iodide in the reaction medium or produced during the reaction of N,N?-(2,3-dihydroxypropyl)-5-hydroxy-1,3-benzenedicarboxamide with I2. The invention also relates to the use of the intermediate compound of formula (I), obtained through the above electrochemical iodination of compound (II), in the preparation of N,N?-bis[2,3-dihydroxypropyl]-5(hydroxyacetyl)methylamino]-2,4,6-triiodo-1,3-benzenedicarboxamide (iomeprol).