Search results for "fluorine"

Synthesis and Influence of 3-Amino Benzoxaboroles Structure on Their Activity against Candida albicans

2020

Benzoxaboroles emerged recently as molecules of high medicinal potential with Kerydin&reg

Thermodynamic and19F NMR studies of antimony trifluoride in water

1993

Densities, specific heat capacities per unit volume and enthalpies of dilution at 25°C and osmotic coefficients at 37°C were measured for antimony trifluoride in water as functions of concentration. From the first three properties the apparent and partial molar volumes, heat capacities and relative enthalpies were derived. As well, pH measurements in water at 25°C and19F NMR spectra in water and methanol at 33°C were also carried out. All the thermodynamic properties together with the chemical shifts abruptly change in the very dilute concentration region (<0.1m) and, then, tend to a constant value. These trends have been rationalized through a simple model based on an equilibrium of dissoc…

Fluorine in pharmaceutical industry: fluorine-containing drugs introduced to the market in the last decade (2001-2011).

2013

H and 19F NMR Investigation on Mixed Hydrocarbon−Fluorocarbon Micelles

2003

1H and 1 9 F NMR measurements on aqueous solutions of sodium perfluorooctanoate (SPFO) and sodium dodecanoate (SD) mixtures are reported. The surfactant concentration ranged from ∼0.3 to 10 times the critical micelle concentration (cmc ≅ 0.03 mol L - 1 ). The cmc of the SD/SPFO/water mixed system obtained from NMR data was in good agreement with that previously obtained by conductivity measurements. Below the cmc, the experimental chemical shift (δ) was independent of the total concentration for both surfactants. Above the cmc, however, the 6 values for 1 9 F varied linearly with concentration, whereas the values for the hydrogenated surfactant deviated from linearity. These observations in…

FLUORINATED DERIVATIVES OF A POLYASPARTAMIDE BEARING POLYETHYLENE GLYCOL CHAINS AS OXYGEN CARRIERS

2008

Abstract In this paper the synthesis and characterization of new fluorinated polymers based on a polyaspartamide bearing polyethylene glycol (PEG) chains, are reported. The starting material was the α,β-poly(N-2-hydroxyethyl)- dl -aspartamide (PHEA), a water soluble and biocompatible polymer, that has been derivatized with both polyethylene glycol (with a molecular weight of 2000 Da) and 5-pentafluorophenyl-3-perfluoroheptyl-1,2,4-oxadiazole. By varying the amount of the fluorinated oxadiazole, three samples have been prepared and characterized by FT-IR, 1H NMR, 19F NMR and UV–VIS spectroscopy. Size exclusion chromatography analysis of these copolymers revealed the occurrence of a self-asso…

Determination of organic fluorine in aqueous samples with neutron activation analysis in comparison with the DIN method

1996

Neutron activation analysis (NAA) has been used as detection technique for adsorbable organic fluorine in aqueous samples. The results have been compared with the standardized DIN method which uses a fluoride-ion-selective electrode (ISE).

Electrochemical Synthesis of Fluorinated Orthoesters from 1,3‐Benzodioxoles

2019

Abstract Invited for this month's cover picture is the group of Professor Siegfried Waldvogel. The cover picture displays the robustness achieved by the installation of fluorinated alcohols on 1,3‐benzodioxoles, protecting the obtained orthoesters against acids and bases, like the shield of a knight. The simple protocol allows access to interesting compounds, whose lipophilicity is tremendously increased by the incorporation of fluorinated groups. This makes it possible to adjust the physicochemical properties of the biologically active 1,3‐benzodioxole motif. The surprisingly high stability against acids and bases gives rise to subsequent functionalizations or direct application in medicin…

1H and13C NMR assignments and conformational analysis of some tetracyclic compounds with a bicyclo[4.2.0]octane ring system

1998

Synthesis and biological evaluation of new bicyclic fluorinated uracils through ring-closing metathesis.

2006

Two families of bicyclic fluorinated uracils have been prepared starting from a gem-difluorinated unsaturated nitrile, by means of a ring-closing metathesis reaction to form the new ring, which is fused at the C-5/C-6 or N-1/C-6 positions of the uracil moiety. The selective formation of olefin regioisomers in the metathesis process can be controlled according to the reaction conditions (catalyst, solvent, and temperature). The acaricidal activities of the resulting compounds have also been investigated.

Synthesis of Fluorinated and Non-Fluorinated Bicyclic Amidines through Ring-Closing Metathesis

2011

[EN] An efficient method for the synthesis of fluorinated and non-fluorinated imidazoazepines by a ring-closing metathesis reaction as the key step is described. The influence of the fluorine atoms on the preparation of these bicyclic systems is also studied.