Abstract: The present invention provides a process for the preparation of a compound of Formula (II): wherein the process comprises: (i) reacting a compound of Formula (I) with pyridine and 2-acetyloxypropanoyl chloride (APC) to give a compound of Formula (II), wherein the compound of Formula (I) has the following structure:

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with propyleneglycol as solvent.

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerization of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with a solvent mixture comprising 1-methoxy-2-propanol and water or methanol.

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with methanol as solvent.

Abstract: A process for the preparation of iodixanol by dimerisation of 5-acetamido-N,N?-bis (2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”) in which, after the dimerisation step, unreacted Compound A is precipitated from the reaction mixture and recovered for re-use. The process substantially increases the net yield of iodixanol and simplifies its purification.

Abstract: A process for the preparation of iodixanol by dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”) in which, after the dimerisation step, unreacted Compound A is precipitated from the reaction mixture and recovered for re-use. The process substantially increases the net yield of iodixanol and simplifies its purification.

Abstract: A process for the manufacture of iodixanol by performing a purification process of the crude product in a solvent comprising n-propanol. The crude product may be obtained in aqueous solution from dimerization of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”).

Abstract: This invention relates generally to industrial preparation of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), a non-ionic X-ray contrasting agent. It further relates to a method of recovering intermediate 5-acetamido-N,N-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (“Compound A”) from the desalinated and desolventized dimerisation reaction mixture. In particular, the present invention employs ultrafiltration to recover non-crystalline Compound A to reduce the overall cost of iodixanol manufacture, increase the yield of iodixanol, and facilitate the subsequent purification procedures to meet the regulatory purity requirement of iodixanol.

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with a solvent mixture comprising 1-methoxy-2-propanol and water or methanol.

Abstract: This invention relates generally to non-ionic X-ray contrast agents. It further relates to a method of using solid adsorbents to reduce backpeaks content in the purification of iodixanol. In particular, it relates to the use of non-polar organic adsorbents with the average pore diameter smaller than about 30 nm. Specific examples of adsorbents of the instant invention include non-polar acrylic ester, di-vinyl benzene resins, poly-styrene di-vinyl benzene resins, and carbon adsorbents. In certain embodiments, upwards of 30% of the backpeak levels and 60% N-acetyl cyclic iodixanol levels are reduced for a 5% loss of iodixanol.

Abstract: This invention relates generally to industrial preparation of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), a non-ionic X-ray contrasting agent. It further relates to a method for preparing a crude mixture of the dimerisation reaction from 5-acetamido-N,N-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophthalamide (“Compound A”) to iodixanol for the crystallization of iodixanol. In particular, it relates to an industrial procedure of simultaneously reducing the salt content and the alcoholic dimerisation solvent using a nanofiltration system prior to the crystallization of iodixanol.

Abstract: This invention relates generally to the preparation of non-ionic X-ray contrast agents, iohexol, ioversol, and iodixanol. It further relates to a method for improving the purity of 5-amino-N,N?-bis(2,3-dihydroxypropyl)-isophthalamide (or ABA), an intermediate in the industrial preparation of these non-ionic X-ray contrast agents. In particular, it relates to a method for significantly removing ABA monomethylester and ABA dimer from ABA by hydrolyzing ABA under a pH between about 12 to about 13 in an aqueous medium to convert ABA monomethylester to ABA monoacid, before the iodination reaction of ABA.

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with methanol as solvent.

Abstract: This invention relates to the synthesis of iodixanol (1,3-bis(acetamido)-N,N?-bis[3,5-bis(2,3-dihydroxypropylaminocarbonyl)-2,4,6-triiodophenyl]-2-hydroxypropane), more specifically to the dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide with propyleneglycol as solvent.

Abstract: This invention relates generally to the preparation of non-ionic X-ray contrast agents, iohexyl, ioversol, and iodixanol. It further relates to a method for improving the purity of 5-amino-N,N?-bis(2,3-dihydroxypropyl)-isophthalamide (or ABA), an intermediate in the industrial preparation of these non-ionic X-ray contrast agents. In particular, it relates to a method for significantly removing ABA monomethylester and ABA dimer from ABA by hydrolyzing ABA under a pH between about 12 to about 13 in an aqueous medium to convert ABA monomethylester to ABA monoacid, before the iodination reaction of ABA.

Abstract: A process for the manufacture of iodixanol by performing a crystallization process of the crude product in a solvent mixture comprising water, methanol and isopropanol. The crude product may be obtained in aqueous solution from dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”).

Abstract: A process for the preparation of iodixanol by dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropy1)-2,4,6-triiodo-isophthalamide (“Compound A”) in which, after the dimerisation step, unreacted Compound A is precipitated from the reaction mixture and recovered for re-use. The process substantially increases the net yield of iodixanol and simplifies its purification.

Abstract: A process for the preparation of iodixanol by dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”) in which, after the dimerisation step, unreacted Compound A is precipitated from the reaction mixture and recovered for re-use. The process substantially increases the net yield of iodixanol and simplifies its purification.

Abstract: A process for the manufacture of iodixanol by performing a purification process of the crude product in a solvent comprising n-propanol. The crude product may be obtained in aqueous solution from dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”).

Abstract: A process for the preparation of iodixanol by dimerisation of 5-acetamido-N,N?-bis(2,3-dihydroxypropyl)-2,4,6-triiodo-isophthalamide (“Compound A”) in which, after the dimerisation step, unreacted Compound A is precipitated from the reaction mixture and recovered for re-use. The process substantially increases the net yield of iodixanol and simplifies its purification.