Heterocyclic Nonionic X-ray Contrast Agents. 4. The Synthesis of Dihydro-2(3H)-furanylidenamino, 5-oxo-1-pyrrolidinyl, and 5-oxo-4-morpholinyl Derivatives by an Intramolecular Iodocyclization Approach
摘要:
Intramolecular iodocyclization of omega-alkenylanilides 6 and [omega-(alkenyloxy)alkyl]anilides 7 resulted in the formation of dihydro-2(3H)-furanylidenamines 8 and 1,4-dioxan-2-ylideneamines 9, respectively, by an amide-oxygen participative nucleophilic attack on the expected iodonium intermediate. The latter heterocyclic ring system is new. If a strong base is present, the mode of ring closure was mainly diverted to an amide-nitrogen participative nucleophilic attack, leading to (iodomethyl)-pyrrolidinones 10 and (iodomethyl)morpholinones 11, from 6 and 7, respectively. Unique interconvertible syn-anti isomerism in the imino-ether 8a was demonstrated by variable temperature NMR studies. The major component in this mixture was the 8a anti-isomer. Acetolysis of the iodocyclized products, followed by deacetylation, provided the heterocyclically substituted polyhydroxytriiodoisophthalamides 16-18. Hydrolytic studies on the imidate 16d revealed an interesting pH dependence. As expected the amine 3d and the amide 22 resulted in pH values of 2 and 6. At pH 12, however, the Chapman rearrangement product 17d was the major product. The compounds obtained in this investigation are of interest as X-ray contrast agents.
Methods and compositions for using non-ionic contrast agents to reduce
申请人:Bracco International B.V.
公开号:US05527926A1
公开(公告)日:1996-06-18
In accordance with the present invention a novel method and composition for using nonionic contrast media to reduce the risk of clot formation in a diagnostic procedure is disclosed. Novel compositions for such method are also disclosed. The present method comprises employing a triiodinated phenyl contrast agent having a heterocyclic group or a dimeric triiodinated phenyl contrast agent having one or more heterocyclic groups.
Methods and compositions for using non-ionic contrast agents to reduce the risk of clot formation in diagnostic procedures
申请人:BRACCO INTERNATIONAL B.V.
公开号:EP0516050A2
公开(公告)日:1992-12-02
In accordance with the present invention a novel method and composition for using nonionic contrast media to reduce the risk of clot formation in a diagnostic procedure is disclosed. Novel compositions for such method are also disclosed. The present method comprises employing a triiodinated phenyl contrast agent having a heterocyclic group or a dimeric triiodinated phenyl contrast agent having one or more heterocyclic groups.
Heterocyclic Nonionic X-ray Contrast Agents. 4. The Synthesis of Dihydro-2(3H)-furanylidenamino, 5-oxo-1-pyrrolidinyl, and 5-oxo-4-morpholinyl Derivatives by an Intramolecular Iodocyclization Approach
作者:T. Arunachalam、H. Fan、K. M. R. Pillai、R. S. Ranganathan
DOI:10.1021/jo00119a020
日期:1995.7
Intramolecular iodocyclization of omega-alkenylanilides 6 and [omega-(alkenyloxy)alkyl]anilides 7 resulted in the formation of dihydro-2(3H)-furanylidenamines 8 and 1,4-dioxan-2-ylideneamines 9, respectively, by an amide-oxygen participative nucleophilic attack on the expected iodonium intermediate. The latter heterocyclic ring system is new. If a strong base is present, the mode of ring closure was mainly diverted to an amide-nitrogen participative nucleophilic attack, leading to (iodomethyl)-pyrrolidinones 10 and (iodomethyl)morpholinones 11, from 6 and 7, respectively. Unique interconvertible syn-anti isomerism in the imino-ether 8a was demonstrated by variable temperature NMR studies. The major component in this mixture was the 8a anti-isomer. Acetolysis of the iodocyclized products, followed by deacetylation, provided the heterocyclically substituted polyhydroxytriiodoisophthalamides 16-18. Hydrolytic studies on the imidate 16d revealed an interesting pH dependence. As expected the amine 3d and the amide 22 resulted in pH values of 2 and 6. At pH 12, however, the Chapman rearrangement product 17d was the major product. The compounds obtained in this investigation are of interest as X-ray contrast agents.