30897-76-8Relevant academic research and scientific papers
Allylic and allenic halide synthesis via NbCl5- and NbBr 5-mediated alkoxide rearrangements
Ravikumar,Yao, Lihua,Fleming, Fraser F.
supporting information; experimental part, p. 7294 - 7299 (2010/01/16)
(Chemical Equation Presented) Addition of NbCl5 or NbBr 5 to a series of magnesium, lithium, or potassium allylic or propargylic alkoxides directly provides allylic or allenic halides. Halogenation formally occurs through a metallahalo-[3,3] rearrangement, although concerted, ionic, and direct displacement mechanisms appear to operate competitively. Transposition of the olefin is equally effective for allylic alkoxides prepared by nucleophilic addition, deprotonation, or reduction. Experimentally, the niobium pentahalide halogenations are rapid, afford essentially pure (E)-allylic or -allenic halides after extraction, and are applicable to a range of aliphatic and aromatic alcohols, aldehydes, and ketones. 2009 American Chemical Society.
Imidazole derivatives and salts thereof and pharmaceutical formulations useful in thrombo-embolic disorders
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, (2008/06/13)
Imidazoles of formula (I) STR1 wherein A is a chemical bond or a straight or branched, saturated or unsaturated, aliphatic residue having from 1 to 6 carbon atoms wherein 1, 2 or 3 of such carbon atoms may be replaced by a corresponding number of heteroatoms selected from oxygen, sulphur and nitrogen providing (in the case of 2 or 3 heteroatoms) that any such heteroatom is not located adjacent to a further such heteroatoms or heteroatoms R is a fused, saturated or unsaturated, non-aromatic carbocyclic, polycyclic ring system; a saturated or unsaturated, carbocyclic spirocyclic ring system, optionally containing one or more ring heteroatoms selected from oxygen, sulphur and nitrogen; or a saturated or unsaturated, carbocyclic bridged-polycyclic ring system, optionally containing one or more ring heteroatoms selected from oxygen, sulphur and nitrogen and having one or more bridges; or AR together represent a straight or branched, saturated or unsaturated, aliphatic residue having 3 to 6 carbon atoms, wherein 1, 2 or 3 of such carbon atoms may be replaced by a corresponding number of heteroatoms selected from oxygen, sulphur and nitrogen providing (in the case of 2 or 3 heteroatoms) that any such heteroatom is not located adjacent to a further such heteroatom or heteroatoms; which aliphatic residue is substituted by at least two groups, which may be the same or different, selected from the groups specified for R above. and acid addition salts and pharmaceutically acceptable bioprecursors thereof. Methods of preparing the imidazoles are disclosed. The imidazoles and their acid addition salts and bioprecursors are useful in the treatment or prophylaxis of thrombo-embolic conditions.
