Fluoro Phenyl Research Articles

Effects of functional group of carbon nanotubes on mechanical properties of carbon fibers

The effects of surface functionalization of carbon nanotubes (CNTs) on the mechanical properties of carbon fibers (CFs) have been investigated. The surface functionalization of CNTs was carried out with a diazonium reagent. Compared to pure PAN, only the fluoro phenyl functionalized CNTs (F-Ph-CNT) incorporated PAN composites showed a significant increase up to 22 °C of Tg and displayed the second peak due to the interfacial interaction between F-Ph-CNT and PAN. Among the samples, 0.5wt% of F-Ph-CNT reinforced CFs exhibited a 46% increase in tensile strength (4.1 GPa) and a 37% increase in modulus (302 GPa), respectively compared to that of pure CFs.

Preparation, nano purification, quality control and labeling optimization of [64Cu]-5,10,15,20-tetrakis (penta fluoro phenyl) porphyrin complex as a possible imaging agent

Cu-64 was produced via the 68Zn (p,αn)64Cu nuclear reaction (≈200 mCi, >95 % chemical yield at 180 μA for 1.1 h irradiation, (radionuclidic purity >96 %, copper-67 as impurity) followed by purification with amino functionalized nano magnetic oxide, Fe3O4 aiming to remove trace amount of heavy metal ions from aqueous media due to achieve ultra pure [64Cu] CuCl2 for labeling step. [64Cu] labeled 5,10,15,20-tetrakis(penta fluoro phenyl) porphyrin ([64Cu]-TFPP) was prepared using freshly prepared [64Cu] CuCl2 (Cu-64; T1/2 = 12.7 h) and 5,10,15,20-tetrakis(penta fluoro phenyl)porphyrin (H2TFPP) for 60 min at 100 °C under reflux condition (radiochemical purity: >97 % ITLC, >98 % HPLC, specific activity: 14–16 GBq/mmol). Stability of the complex was checked in final formulation and human serum for 24 h. The partition coefficient was calculated for the compound (log P = 0.73). The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and PET imaging up in 2 and 4 h after injection. A detailed comparative pharmacokinetic study performed for 64Cu cation and [64Cu]-TFPP. The complex is mostly washed out from the circulation through kidneys and liver and can be an interesting tumor imaging/targeting agent due to high specific uptake and rapid excretion through the urinary tract.

Optimization of Ullmann Reaction Step in the Synthesis of Sertindole

5-chloro-1-(4- fluorophenyl)-indole is a key intermediate of sertindole. It can be synthesized from 4-fluoro-bromobenzene and 5-chloroindole by Ullmann reaction, but this step required significant optimization to improve yield and reproducibility for the purity processes of the syntheses that have been disclosed are quite complicated and the reaction proceeds usually can’t go to completion. The Ullmann reaction step in the synthesis of sertidole was improved by using purified 5-chloroindole, suitable catalyst and solvent. A viable kilo-scale synthesis of the 5-chloro-1-(4- fluoro phenyl)-indole was described. Simple workup, economical, high yields and purity of product are some advantages of this method.

(S)-2-[(R)-Fluoro(phenyl)methyl]oxirane: A General Reagent for Determining the ee of α-Chiral Amines

(<i>S</i>)-2-[(<i>R</i>)-Fluoro(phenyl)methyl]oxirane: A General Reagent for Determining the ee of α-Chiral Amines

Acetoxy(fluoro)(phenyl)silanes C6H5Si(OCOCH3) n F3−n

Acetoxy(fluoro)(phenyl)silanes C6H5Si(OCOCH3) n F3−n

Blue phosphorescent iridium complexes based on 2-(fluoro substituted phenyl)-4-methylpyridines: Synthesis, crystal structure, and photophysics

A series blue phosphorescent emitting materials based on 2-(fluoro substituted phenyl)-4-methylpyridine as the cyclometalated ligands have been synthesized and characterized. The complexes have the general structure (C ^N) 2Ir(pic), where C ^N is a monoanionic cyclometalating ligand (e.g., 2-(2,4-difluorophenyl)-4-methylpyridine (24f 2pmpyH), 2-(3,4-difluorophenyl)-4-methylpyridine (34f 2pmpyH), 2-(3,5-difluorophenyl)-4-methylpyridine (35f 2pmpyH), and 2-(3,4,5-trifluorophenyl)-4-methyl-pyridine (345f 3pmpyH)), pic is 2-picolinic acid. The absorption, emission, cyclic voltammetry and thermostability of the complexes were systematically investigated. The (46f 2pmpy) 2Ir(pic) has been characterized using X-ray crystallography and the electronic ground state calculated using B3LYP density functional theory. HOMO levels are a mixture of Ir and 2-(fluoro phenyl)-4-methylpyridine ligand orbitals, while the LUMO is predominantly pic ligand based. Introduction of fluorine atoms and methyl group into ppy ligand and changing in position of F substituents in phenyl ring can finely tune emission of the complexes, showing bright blue-to-green luminescence at a wavelength of 463–501 nm at room temperature in CH 2Cl 2.

Reaction of Fluoro(phenyl)carbene with Schiff Bases: Synthesis of 2-Fluoro-2-phenylaziridines

Fluoro(phenyl)carbene generated by reaction of α-bromo-α-fluorotoluene with potassium tert-butoxide reacts with Schiff bases to afford the corresponding 2-fluoro-2-phenylaziridines. The latter were isolated in low yields due to their instability under the carbene generation conditions. Although the reaction of α,α-dibromo-α-fluorotoluene with zinc and lead involves formation of fluoro(phenyl)carbene, this procedure is not suitable for the synthesis of 2-fluoro-2-phenylaziridines.

Synthesis and evaluation of 4-substituted semicarbazones of levulinic acid for anticonvulsant activity.

A series of 4-aryl substituted semicarbazones of levulinic acid (4-oxo pentanoic acid) was designed and synthesized to meet the structural requirements essential for anticonvulsant activity. All the compounds were evaluated for anticonvulsant activity. Anticonvulsant activity was determined after intraperitoneal (i.p.) administration to mice by maximal electroshock (MES) and subcutaneous metrazol (ScMet) induced seizure methods and minimal motor impairment was determined by rotorod test. A majority of the compounds exhibited significant anticonvulsant activity after intraperitoneal administration. In the present study 4-(4'-fluoro phenyl) levulinic acid semicarbazone emerged as the most active molecule, showing broad spectrum of activity with low neurotoxicity. Unsubstituted levulinic acid semicarbazone was found to be inactive in all the screens. The results obtained validate the hypothesis that presence of an aryl group near the semicarbazone moiety is essential for anticonvulsant activity. The results also indicate that the hydrophilic-hydrophobic site can accommodate hydrophilic groups.

Enantioselective microbial reduction of substituted acetophenones

The chiral intermediate ( S)-1-(2′-bromo-4′-fluoro phenyl)ethanol 2 was prepared by the enantioselective microbial reduction of 2-bromo-4-fluoro acetophenone 1. Organisms from genus Candida, Hansenula, Pichia, Rhodotorula, Saccharomyces, Sphingomonas and Baker's yeast reduced 1 to 2 in >90% yield and 99% enantiomeric excess (ee). In an alternative approach, the enantioselective microbial reductions of methyl, ethyl, and tert-butyl 4-(2′-acetyl-5′-fluorophenyl) butanoates 3, 5, and 7, respectively, were demonstrated using strains of Candida and Pichia. Reaction yields of 40–53% and ee's of 90–99% were obtained for the corresponding ( S)-hydroxy esters 4, 6, and 8. The reductase, which catalyzed the enantioselective reduction of ketoesters was purified to homogeneity from cell extracts of Pichia methanolica SC 13825. It was cloned and expressed in Escherichia coli with recombinant cultures used for the enantioselective reduction of keto methyl ester 3 to the corresponding ( S)-hydroxy methyl ester 4. On a preparative scale, a reaction yield of 98% and an ee of 99% was obtained.

Polymerization of N‐(fluoro phenyl) maleimides

AbstractPoly(N‐aryl maleimide)s of characteristic structures have been synthesized and some of their physical properties studied. These include N‐(2‐fluoro phenyl), N‐(3‐fluoro phenyl), N‐(4‐fluoro phenyl), N‐(2,4‐difluoro phenyl), N‐(2,5‐difluoro phenyl), N‐(2,3,5,6‐tetrafluoro phenyl), and N‐(pentafluoro phenyl). The polymerization of N‐(fluoro phenyl) maleimides by free‐radical initiation in bulk or in solution and by anionic catalyst have been studied to compare the characteristics of polymerization by γ‐ray irradiation with that by free‐radical initiation. The polymers were characterized by elemental analysis, intrinsic viscosity, spectroscopy (IR and NMR), programmed thermogravimetric analysis, and x‐ray diffraction. Spectra of polymers prepared by radiation and anionic polymerization were nearly identical with those of polymers prepared by free‐radical polymerization initiated by AIBN in bulk or in solution and by the self‐initiated thermal polymerization. A variety of reaction conditions were tried, but all attempts to change the molecular structure of the polymers were unsuccessful. Rates of thermal degradation for poly[N‐(fluoro phenyl) maleimide]s have been analyzed by using a multiple‐heating‐rate procedure. Overall activation energy, order of reaction, and frequency factor have been evaluated. On the basis of the comparison between the overall activation energy of the thermal degradation of poly[N‐(fluoro phenyl) maleimide]s and NMR spectra of their corresponding monomers, it can be concluded that the 1H shifts due to ethylenic protons are so characteristic in sign and magnitude as to be useful in thermal stability elucidation. Some qualitative explanations were given on the stability of these polymers as affected by the type and size of the substituent. The x‐ray diffractograms of all samples show two rather broad peaks indicative of noncrystalline structures. The location of the peaks does not depend upon preparation conditions and temperature. Poly(N‐maleimide)s of fluoroanilines have not been hitherto described.

Synthesis of N-(fluoro phenyl) maleamic acids and N-(fluoro phenyl) maleimides

A series of seven N-(fluoro phenyl) maleamic acids and their N-(fluoro phenyl) maleimides were prepared by the reaction of fluoro phenyl amines ( o-, m-, and p-fluoro, 2.4-, 2.5-difluoro, 2.3.5.6-tetrafluoro and 2.3.4.5.6.-pentafluoro anilines) with maleic anhydride according to substantial modifications made to the reaction conditions used by Searle for the preparation of normal N-aryl maleimides.