15086-94-9Relevant articles and documents
Novel β-cyclodextrin-eosin conjugates
Benkovics, Gábor,Afonso, Damien,Darcsi, András,Béni, Szabolcs,Conoci, Sabrina,Fenyvesi, éva,Szente, Lajos,Malanga, Milo,Sortino, Salvatore
, p. 543 - 551 (2017)
Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.
Electrophilic bromination in flow: A safe and sustainable alternative to the use of molecular bromine in batch
Van Kerrebroeck, Reinout,Naert, Pieter,Heugebaert, Thomas S.A.,D’hooghe, Matthias,Stevens, Christian V.
, (2019/06/10)
Bromination reactions are crucial in today’s chemical industry since the versatility of the formed organobromides makes them suitable building blocks for numerous syntheses. However, the use of the toxic and highly reactive molecular bromine (Br2) makes these brominations very challenging and hazardous. We describe here a safe and straightforward protocol for bromination in continuous flow. The hazardous Br2 or KOBr is generated in situ by reacting an oxidant (NaOCl) with HBr or KBr, respectively, which is directly coupled to the bromination reaction and a quench of residual bromine. This protocol was demonstrated by polybrominating both alkenes and aromatic substrates in a wide variety of solvents, with yields ranging from 78% to 99%. The protocol can easily be adapted for the bromination of other substrates in an academic and industrial environment.
Synthese d'eosine pure
Fompeydie, Dominique,Onur, Feyyaz,Levillain, Pierre
, p. 5 - 6 (2007/10/02)
According to solubilities of fluorescein and its brominated derivatives, pure eosin (2,4,5,7-tetrabromofluorescein) is prepared with a good yield (about 85 percent) by reaction of Br-/BrO3- on fluorescein in acidic water-acetone mixture.We have determined the exact composition of this medium which allows the precipitation of eosin while the other brominated derivatives of fluorescein remain soluble.