696-01-5Relevant articles and documents
Fluoro-substituted and 13C-labeled styrylbenzene derivatives for detecting brain amyloid plaques
Sato, Kumi,Higuchi, Makoto,Iwata, Nobuhisa,Saido, Takaomi C.,Sasamoto, Kazumi
, p. 573 - 578 (2007/10/03)
Two styrylbenzene derivatives, (E,E)-1-fluoro-2,5-bis-(3-hydroxycarbonyl-4- hydroxy)styrylbenzene (FSB) and (E,E)-1-bromo-2,5-bis(3-hydroxycarbonyl-4- hydroxy)styrylbenzene-α,α′-13C2 ([ 13C]BSB), were synthesized for use as a histochemical stain to detect amyloid plaques of Alzheimer's disease (AD) brain sections. An analysis of fluorescence spectra demonstrated that FSB shows approximately twofold fluorescence intensity relative to the conventional styrylbenzene derivative, (E,E)-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB). Moreover, FSB was found to stain amyloid plaques and neurofibrillary tangles of AD brains with greater fluorescence intensity and a lower level of background signals compared to BSB. These finding indicate that FSB can be an excellent fluorescent compound to label human amyloid lesions with high sensitivity and specificity. Because of the possession of a nuclide with a quantized angular momentum, both FSB and [13C]BSB are also potential contrast agents for magnetic resonance imaging to locate AD pathologies in vivo.
A product analytical study of the thermal and photolytic decomposition of some arenediazonium salts in solution
Canning, Peter S. J.,Maskill, Howard,McCrudden, Katharine,Sexton, Brian
, p. 789 - 800 (2007/10/03)
Products of thermal and photochemical reactions of eleven arenediazonium tetrafluoroborates in various solvents have been analyzed. All compounds in most solvents undergo unimolecular heterolysis to give singlet aryl cations which are captured by solvent. This mechanism is dominant for arenediazonium ions without electron-withdrawing substituents in all solvents, and the only reaction observed in water. Additionally, appreciable yields of fluoroarenes are obtained by fluoride abstraction by the aryl cation from fluorinated solvents and from tetrafluoroborate in fluorinated solvents. Yields from photochemical processes are very similar to those from thermal reactions indicating that the main reactions proceed through common or very similar intermediates. Aryl cations formed from ion-paired diazonium ions may react with the counterion, but fragmentation of dissociated diazonium ions leads only to solvent-derived product. Some arenediazonium ions in some solvents undergo an alternative radical reaction leading principally to hydrodediazoniation. It is proposed that this reaction involves initial rate-limiting electron transfer from ethanol to the arenediazonium ion followed rapidly by homolysis of the resultant aryldiazenyl radical. Within the same solvent cage, the aryl radical then either abstracts an α-hydrogen from the ethanol radical cation generated in the first step to give the reduction product and protonated acetaldehyde, or combines with it at the oxygen to give a protonated aryl ethyl ether.
Preparation process of fluorine substituted aromatic compound
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, (2008/06/13)
A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.
