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[en] Data on electrophilic fluorination of aromatic, heteroaromatic and organoelement compounds are generalized and analyzed. The attention is focused on the factors determining the selectivity of fluorine atom substitution for hydrogen in the aromatic ring.
[en] A topological analysis of HF/6-31++G**//HF/6-31G* electron distributions on diverse conformers of 36 linear fluoroalkanes of formula CHnF3-n(CH2)mCH3 was carried out within the atoms in molecules (AIMs) formalism. Group energy additivity of molecular energies was found in spite of lack of energy transferability. Cooperative effects due to stepwise fluorination on carbon 1 that appear to be around to 90 kJ mol-1 according to traditional analysis based upon fitted group energies, exceed 370 kJ mol-1 when obtained from AIMs energies. Mean values of atomic properties and empirical relationships between concrete atomic properties lead to a definition of transferable fragments. It was found that the effect of fluorine atom on the chain is appreciable at further carbons for trans than for gauche arrangements, whereas effects on the hydrogen atoms give rise to an oscillatory behaviour (related to F-H interatomic distances) displayed along the whole chain
[en] Sultones were subject to ring opening by nucleophilic attack with [18F]fluoride to afford easily purified 18F-labelled hydrophilic sulfonated products in high yields. A two-step sequence including radio-fluorination and coupling to lysine was then developed from a bis-sultone precursor as a model approach for the labelling of biopolymers. (authors)
[en] A one-pot, facile and ecofriendly approach to the fabrication of covalently fluorinated graphene using mild reaction conditions is reported. This straightforward and efficient strategy allows fluorine groups to be covalently and stably anchored onto graphene to produce single-layer functionalized graphene sheets from a graphene oxide precursor
[en] A facile procedure for preparing 4-fluoroantipyrine is reported. Treatment of antipyrine with molecular fluorine gives 4-fluoroantipyrine (3) and 4,4-difluoro-3-hydroxy-2,3-dimethyl-1-phenylpyrazolidin-5-one (2). The product distribution depends on the ratio of antipyrine and molecular fluorine. The same procedure is used to prepare [18F]-4-fluoroantipyrine with high specific activity. (author)
[en] 2-(2-(3-(4-(2-[18F]Fluoroethoxy)phenyl)-7-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)ethyl)-4-isopropoxyisoindoline-1,3-dione ([18F]MNI-659, [18F]1) is a useful PET radiotracer for imaging phosphodiesterase 10A (PDE10A) in human brain. [18F]1 has been previously prepared by direct [18F]fluorination of a tosylate precursor 2 with [18F]F−. The aim of this study was to determine the conditions for the [18F]fluorination reaction to obtain [18F]1 of high quality and with sufficient radioactivity for clinical use in our institute. Moreover, we synthesized [18F]1 by [18F]fluoroethylation of a phenol precursor 3 with [18F]fluoroethyl bromide ([18F]FEtBr), and the outcomes of [18F]fluorination and [18F]fluoroethylation were compared.