Heterocyclic Nonionic X-ray Contrast Agents. III. The Synthesis of 5-[4-(Hydroxymethyl)-2-oxo-3-oxazolidinyl]-2,4,6-triiodo-1,3-benzenedicarboxamide Derivatives

Synthesis and Preclinical Characterization of a Cationic Iodinated Imaging Contrast Agent (CA4+) and Its Use for Quantitative Computed Tomography of Ex Vivo Human Hip Cartilage

“…Additionally, multiple iodinated aromatic rings are fused together in order to reduce osmolality while maintaining high administered iodine content. Though several contrast agents (ionic, nonionic, and one/two aromatic ring structures) are approved for clinical use and produced worldwide, new contrast agents with high water solubility, low viscosity and osmolality, and reduced toxicity continue to be of interest. − Contrast agents that go beyond qualitative visualization and enable quantitative assessments of functional tissue performance represent the next (third) generation of contrast agents. One clinical area where such contrast agents can have a significant impact is in the diagnosis of soft tissue-based diseases like osteoarthritis (OA).…”

Optimisation of the Preparation and Isolation of 5-Amino-2,4,6-triiodoisophthalic Acid Dichloride

“…Commercially available solvents and reagents were used without further purification. 5-Amino-2,4,6-triiodoisophthalic acid was prepared according to literature procedures …”

“…Drying was performed at 40 °C under vacuum to give 547 g of 5 (85.5%). Analytical and spectroscopic data were identical to those described in ref .…”

“…The 5-amino-2,4,6-triiodoisophthalic moiety is the basic backbone responsible for the contrasting capability of many water-soluble, nonionic iodinated X-ray contrast agents for imaging soft tissues, such as Iopamidol ( 1 ), Iohexol ( 2 ), and Ioversol ( 3 ). Consequently, several examples of the synthesis of the key intermediate building block 5-amino-2,4,6-triiodoisophthalic acid chloride ( 5 ) have been reported. − Conversion of 5-amino-2,4,6-triiodoisophthalic acid ( 4 ) to the corresponding acid chloride 5 is usually carried out using thionyl chloride as the chlorinating agent.

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Stereoselective intramolecular cyclization to 4‐(hydroxymethyl)‐3‐(1H‐indolyl)oxazolidin‐2‐ones

“…Hence, in this communication, we report a regioselective and stereoselective synthesis of 4‐(hydroxymethyl)‐3‐(1 H ‐indolyl)oxazolidin‐2‐ones, based on the intramolecular reaction of glycidyl‐ N ‐indolylcarbamates 6 and 7 (Scheme ). It is noteworthy that this procedure may be applied to get some chiral N‐ substituted 4‐(hydroxymethyl)oxazolidin‐2‐ones 23…”