Structural, electrical and dielectric properties of (Sr1−xCax) MnO3 (0≤x≤1.0) ceramics

Publisher Summary This chapter deals with polyfluoroheterocycles. It essentially describes the six-membered ring heterocycles and complements a review by Burger that covers fluorine-containing five-membered heterocyclic rings. In specific, the chapter illustrates the literature from 1981 to date. It considers updating the review of Chambers and Sargent on polyfluoroheterocyclic chemistry as well as bringing out other aspects of fluoroheterocycles. The process of synthesis of polyfluoroheterocycles can be essentially separated into three sections, depending on whether fluorine or polyfluoroalkyl group is introduced into a heterocycle, or whether the heterocycle is formed from fluorinated synthons. Several uses of fluorinated heterocycles are reported. Trifluoromethyl pyridines are useful building blocks for agrochemicals. A new class of fluoropolymers based on the bis-2,2-(trifluoromethyl)-4,5-difluoro-1,3-dioxole structure offers the usual properties expected from fluoropolymers together with good optical clarity and high glass transition temperature. Also the ease of displacement of fluorine from polyfluoroheterocycles creates a lot of interest in their introduction into fiber-reactive dyes. The chapter also describes the properties and reactions of the fluoroheterocycles compounds.

Recent advances in fluoroheterocyclic chemistry

Indirect electrochemical reduction, by means of an aromatic anion mediator, of perfluoroalkyl halides (CF3Br, n-C4F9I, n-C6F13I, I(CF2)4I) in the presence of imidazole, 4(5)-nitroimidazole, 2-methyl-5-nitroimidazole, 2-(4‘-methoxyphenyl)imidazole, imidazole-2-carboxaldehyde, 4(5)-nitroimidazole-2-carboxaldehyde, 5(6)-nitrobenzimidazole, purines (adenine, hypoxanthine, xanthine, theophylline, lumazine) and pyrimidine anions (uracil, cytosine, barbituric acid) yields the corresponding C-perfluoroalkylated nitrogen bases by an SRN1 mechanism. Aromatic nucleophilic substitution of some fluorinated aryl halides 1-iodo-2-(trifluoromethyl)benzene and 1-(4‘-iodo-tetrafluorophenyl)imidazole was also investigated and it was found that 1-iodo-2-(trifluoromethyl)benzene could react successfully under redox-catalyzed conditions with imidazole, 2-(4‘-methoxyphenyl)imidazole anion, and uracil anion to give the corresponding 5-(fluorinated-aryl) nitrogen bases. In the case of 1-(4‘-iodo-tetrafluorophenyl)imidazole, direc...

A Convenient Synthesis of Perfluoroalkylated and Fluorinated-Aryl Nitrogen Bases by Electrochemically Induced SRN1 Substitution

One-pot synthesis of 2-trifluoromethyl and 2-difluoromethyl substituted benzo-1,3-diazoles

Radioligand binding assays using bovine cortical membrane preparations and biochemical in vitro studies revealed that various 3-aryl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-one (ATBI) derivatives, previously reported by us as ligands of the central benzodiazepine receptor (BzR) (Primofiore, G.; et al. J. Med. Chem. 2000, 43, 96−102), behaved as antagonists at the A1 adenosine receptor (A1AR). Alkylation of the nitrogen at position 10 of the triazinobenzimidazole nucleus conferred selectivity for the A1AR vs the BzR. The most potent ligand of the ATBI series (10-methyl-3-phenyl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-one 12) displayed a Ki value of 63 nM at the A1AR without binding appreciably to the adenosine A2A and A3 nor to the benzodiazepine receptor. Pharmacophore-based modeling studies in which 12 was compared against a set of well-established A1AR antagonists suggested that three hydrogen bonding sites (HB1 acceptor, HB2 and HB3 donors) and three lipophilic pockets (L1, L2, and L3) might be avail...

3-Aryl[1,2,4]triazino[4,3-a]benzimidazol-4(10H)-ones: a new class of selective A1 adenosine receptor antagonists.

Fluorine-containing bioactive benzimidazoles

Lattice parameter and corresponding total free energy have been computed for cubic SrMO3 perovskites (M = Ti, Zr, Mo, Rh, Ru) using the first principle approach within Density functional theory. The results have been calculated using local density approximation (LDA) method. It is found that the calculated lattice parameter for all transition metal oxides are in good agreement with the available experimental data. The total free energy corresponding to this lattice constant has been calculated along with different components of the total free energy. All these calculations have been carried out using ABINIT computer code.

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First Principle Study of Cubic SrMO 3 Perovskites (M = Ti, Zr, Mo, Rh, Ru)

Studies in Spiro-Heterocycles. Part 12. Synthesis of Some Fluorine Containing Spiro(3H-indole-3,4′(4H)-pyrano(2,3-d)pyrimidine)-2,5′,7′(1H)-triones as CNS Agents.

A green synthesis of the title 4-formylpyrazoles (V) and their conversion into corresponding chalcones (VII) and Schiff bases (IX) are described.

Synthesis, Reactions and Anthelmintic Activity of 1-[Benzimidazol-2-yl]-4-formyl-3-[2′-(substituted phenyl)indole-3-yl] Pyrazoles.

/pdf/dielectric-properties-of-water-at-microwave-frequencies-3j8m708j7v.pdf

K. S. Sharma

Papers

Fluorine-containing bioactive benzimidazoles

First Principle Study of Cubic SrMO 3 Perovskites (M = Ti, Zr, Mo, Rh, Ru)

Studies in Spiro-Heterocycles. Part 12. Synthesis of Some Fluorine Containing Spiro(3H-indole-3,4′(4H)-pyrano(2,3-d)pyrimidine)-2,5′,7′(1H)-triones as CNS Agents.

Synthesis, Reactions and Anthelmintic Activity of 1-[Benzimidazol-2-yl]-4-formyl-3-[2′-(substituted phenyl)indole-3-yl] Pyrazoles.

Dielectric Properties of Water at Microwave Frequencies