Showing papers on "Aryl radical published in 1998"

Phototoxicity associated with diclofenac: a photophysical, photochemical, and photobiological study on the drug and its photoproducts.

Abstract: Diclofenac (1) is a photosensitizing nonsteroidal antiinflammatory drug. Its photodecomposition gives rise to chlorocarbazole 2a. This product undergoes photodehalogenation to 3a in a subsequent step. When the photobiological activities of 1, 2a, and 3a are compared by means of the photohemolysis test, it is clearly observed that chlorocarbazole 2a causes cell lysis with a markedly higher efficiency than the parent drug or the secondary photoproduct 3a. Laser flash photolysis studies suggest that photodehalogenation of 2a occurs from its excited triplet state via quenching by ground-state 2a and formation of an excimer. As a consequence, an aryl radical plus an N-centered carbazolyl radical are formed. These radical intermediates appear to be responsible for the observed photobiological effects of diclofenac, via hydrogen abstraction from the target biomolecules, which initiates a type-I photodynamic effect. The efficient peroxidation of model lipids, such as linoleic acid, photosensitized by 2a are in fa...

The reaction of iodine with 9-methylacridine: formation of polyiodide salts and a charge-transfer complex

Abstract: The reaction of iodine and 9-methylacridine in methylene chloride results not in the formation of a charge-transfer complex as with acridine, but in the iodine-rich salt [ICH2C13H8N–H]4(I8)(I5)2, 8, where a proton on the methyl group has been replaced by an iodine. In toluene, the reaction produces both a charge-transfer complex ICH2C13H8N–I2, 9, and a salt [CH3–acridine(H)]2(I7)(I5), 10. Polyiodide salt formation can be explained by the availability of a facile reaction pathway from the aryl radical cation which results from initial oxidation by I2.

Mixture of alkyl-phenyl-sulfonates of alkaline earth metals, its application as an additive for lubricating oil, and methods of preparation

Abstract: Mixture of alkyl aryl sulfonates of superalkalinized alkaline earth metals comprising: (a) 50 to 85% by weight of a mono alkyl phenyl sulfonate with a C 14 to C 40 linear chain wherein the molar proportion of phenyl sulfonate substituent in position 1 or 2 is between 0 and 13%, and (b) 15 to 50% by weight of a heavy alkyl aryl sulfonate, wherein the aryl radical is phenyl or not, and the alkyl chains are either two linear alkyl chains with a total number of carbon atoms of 16 to 40, or one or a plurality of branched alkyl chains with on average a total number of carbon atoms of 15 to 48. Inasmuch as these mixtures contain less than 10% of linear mono alkyl phenyl sulfonate substituted in position 1 or 2 of the linear alkyl chain, they exhibit properties making them fit for use as detergent/dispersant additives for lubricating oils.

Aryl radical endo cyclization of enamidines. Selective preparation of trans and cis fused octahydrobenzo[f]quinolines

Abstract: Aryl radicals from N-protected 6-[2-(2-halophenyl)ethyl]-1,2,3,4-tetrahydropyridines and 6-[3-(2-halophenyl)propyl]-1,2,3,4-tetrahydropyridines undergo intramolecular cyclization onto the enamide/enamidine double bond by 6-endo and 7-endo closure, respectively. In the 6-endo cyclization the trans/cis ratio of the formed N-protected octahydrobenzo[f]quinoline can be controlled, and selective synthesis of either the trans or the cis isomer can be achieved with triphenyltin hydride and tris(trimethylsilyl)silicon hydride, respectively. In the 7-endo cyclization to N-protected octahydro-1H-benzo[3,4]cyclohepta[1,2-b]pyridine, the trans fused isomer predominates, although the selectivity is low. The oxidized cyclization products, with a restored enamide/enamidine double bond, are formed at low concentrations of tris(trimethylsilyl)silicon hydride.

Modification of the reductive pathway in gamma-irradiated DNA by electron scavengers: targeting the sugar-phosphate backbone.

Abstract: Several electron scavengers that irreversibly form potential hydrogen-abstracting species upon one-electron reduction have been tested as agents for conversion of reductive damage to DNA bases into damage to the sugar-phosphate backbone. Electron spin resonance spectroscopy is employed to follow the production of radicals and transformations after irradiation. The scavengers tested included neutral (acrylamide, iodoacetamide) and cationic [triphenylsulfonium (Ph 3 S + ), o,o'-diphenylenebromonium (DPB) and o,o'-diphenyleneiodonium (DPI)] compounds. Modification of reductive radiation damage in DNA is found to occur by scavenging of initial mobile electrons at low temperatures as well as thermally activated electron transfer from DNA electron-gain centers upon annealing. Electron transfer from the bases to hydrogen-bonded acrylamide has the smallest activation energy among other scavengers but produces a secondary alkyl radical incapable of abstracting hydrogen from the sugar-phosphate backbone. A primary alkyl radical generated from iodoacetamide has been shown to abstract preferentially from the thymine methyl group but not from deoxyribose moieties. Aryl radicals generated from aromatic onium salts such as Ph 3 S + , and especially DPI and DPB, are found to be the agents which best hydrogen atoms from the deoxyribose portion of DNA. The use of DPB and DPI as radiation modifiers allows the elimination of undesirable side reactions of aryl radicals and through hydrogen abstraction results in high yields of a species identified as the DNA C1' . sugar radical. The second reaction pathway found for DPI and DPB in DNA is addition of an aryl radical to the thymine 5,6 double bond. Cysteamine is shown to preferentially eliminate sugar radicals upon annealing and to have little impact on the thermal stability of the thymine adduct radical.

Synthesis and study of iodonium borate salts as photoinitiators

Abstract: Iodonium butyltriphenylborate salts (AI+Ar′Ph3B−R), (Bu) were found to be more efficient than iodonium tetraphenylborate salts (RPh) when used as photoinitiators for the polymerization of acrylates Relative photodecomposition rates were also different It was found from a study of the photoreaction of iodonium borate salts with a model monomer, methyl methacrylate, that iodonium butyltriphenylborate salts simultaneously produce a butyl radical from the borate anion and an aryl radical from the iodonium cation upon irradiation Both radicals initiate polymerization Iodonium tetraphenylborate salts were found to release an aryl radical, but only from the iodonium cation Iodonium borate salts exhibit strong absorption below 300 nm with a tail absorption above 400 nm Thus, iodonium butyltriphenyl borate salts are efficient photoinitiators even when used with visible light When a photosensitizer such as 5,7-diiodo-3-butoxy-6-fluorone is employed, iodonium butyltriphenylborate salts are rendered much more efficient for visible light photopolymerization © 1998 John Wiley & Sons, Inc J Polym Sci A: Polym Chem 36: 1667–1677, 1998

Novel arylpiperazine derived from piperidine as antidepressant medicines

Abstract: The invention concerns compounds of formula (I) in which in particular, R1 represents R'1, OR'1, SR'1, NHR'1, COR'1, CHOHR'1, CH2R'1, in which R'1 represents an aryl radical selected among a phenyl, a naphthyl or a pyridyl; R2 represents a halogen (Cl, F, Br), OH, NH2, CN, NO2, R'2, OR'2, SR'2, NHR'2, COR'2, CHOHR'2, COOR'2, NHCOR'2, NHCOOR'2, NHSO2R'2, OCONHR'2, in which R'2 represents an alkyl chain linear or branched, an aryl or an arylalkyl; Z represents CO-(CH2)n-O, CO-(CH2)n-NH, (CH2)m-O,(CH2)m-NH, CO-(CH2)p-CONH-, (CH2)p-CONH, CO-(CH2)p-NHCONH-, (CH2)m-NHCONH, -CO(CH2)p-OCONH-, (CH2)m-OCONH, -CO(CH2)p-NHCOO, (CH2)m-NHCOO, in which n represents zero or a whole number ranging between 1 and 8, m represents a whole number ranging between 2 and 8 and p represents a whole number ranging between 1 and 8; Ar represents an aromatic radical such as a phenyl or a naphthyl; R3 represents an alkyl radical linear or branched containing 1 to 6 carbon atoms: These compounds are particularly useful as antidepressant drugs.

Bi-aromatic compounds and pharmaceutical and cosmetic compositions containing same

Abstract: The invention concerns bi-aromatic compounds of formula (I) in which Ar represents (a), (b) or (c); Z being O or S, R1 is -CH3, -CH2-O-R6, -OR6 or -COR7; R2 is -OR8, -SR8 or a polyether radical if in the latter case R4 is C1-C20 alkyl and is in ortho or meta position relative to X-Ar; R3 is alkyl or R2 and R3 together form a cycle optionally interrupted by O or S; R4 is H, halogen, C1-C20 alkyl, -OR8, a polyether or aryl radical; R5 is H, halogen, C1-C20 alkyl or -OR8; R6 is H, alkyl or -COR9; R7 is H, alkyl, -N(r')(r') or -OR10; R8 is H, alkyl or -COR9; R9 is alkyl; R10 is H, C1-C20 alkyl, alkenyl, monohydroxyalkyl or polyhydroxyalkyl, aryl or aralkyl or a sugar residue, r' and r'' are H, alkyl, mono- or polyhydroxyalkyl, aryl, an amino acid or sugar residue or together form a heterocycle, X represents a radical of formula (d) or (e) in which R11 is H or -OR6; R12 is H or alkyl; or R11 and R12 form an oxo radical, and the salts, optical and geometrical isomers of the compounds of formula (I).

Catalytic synthesis of n-alkylated anilines from olefins and anilines

Abstract: The invention relates to a method for producing a N-alkylated aniline of formula (I) Ar-N(R1)2-n(CHR?2CHR3Ar')?n by reacting an aromatic olefin of formula (II) Ar'CR3=CHR2 with an aniline of formula (III) Ar-N(R1)2-n(H)n in an inert solvent and in the presence of at least one basic catalyst selected from the group of alkali alcoholates and alkaline-earth alcoholates or alkali amides and alkaline-earth amides, whereby in formulas (I) to (III); Ar and Ar', independent of one another, represent an aryl radical selected from the group of the condensed and non-condensed C6-C22-aromatic compounds and of the condensed or non-condensed C5-C22-heteroatoms which contain at least one nitrogen, oxygen or sulfur atom in the ring; R1, R2, R3, independent of one another, represent a hydrogen atom, a C1-C8-alkyl radical or an aryl radical Ar; and n represents the number 1 or 2.

Quaternary ammonium phosphate compound and method of preparing same

Abstract: Disclosed is a quaternary ammonium phosphate compound having formula (1) and which has an anticorrosive and a biocidal effect to have a capability of preventing corrosion of various metals including corrosive metal substances, e.g. carbon steels, iron casts, stain steels, coppers, tinning steel plates or alumina and an efficient method of preparing the same. In formula (1), R1 is a straight or a branched alkyl or aryl radical with 1 to 27 carbon atom(s) free of —OH group and may contain hetero-atoms, and both R2 and R3 are methyl groups or R2 and R3 are combined to form a heterocyclic compound with 4 to 6 of carbon atoms containing oxygen and nitrogen.

Catalyst preparations for producing olefin (co)polymers

Abstract: The invention relates to a catalyst preparation which can be obtained by mixing a metal complex (A) wherein the substituents have the following meaning: M means chromium, molybdenum or wolframium; Z means fluorine, chlorine, bromine, iodine, hydrogen or C1 - C20 alkyl; R1 to R5 independently mean hydrogen, C?1? - C10 alkyl, C3 to C7 cycloalkyl unsubstituted or substituted by C1 - C10 alkyl, C6 - C18 aryl, and substituted C6 - C18 aryl and 2 adjacent radicals can jointly mean saturated or unsaturated cyclic groups with 4 to 18 C atoms, or Si(R?6)?3 with R6 meaning independently C1 - C10 alkyl, C3 to C10 cycloalkyl or C6 - C18 aryl, Y means independently C1 - C20 alkyl, C3 to C10 cycloalkyl, C6 - C18 aryl or aralkyl with 1 to 10 C atoms in the alkyl radical and 6 to 18 C atoms in the aryl radical; and a metallocene-ion forming compound (B) in an inert liquid reaction medium.

Total Synthesis of seco-(+)- and ent-(-)-Oxaduocarmycin SA: Construction of the (Chloromethyl)indoline Alkylating Subunit by a Novel Intramolecular Aryl Radical Cyclization onto a Vinyl Chloride.

Abstract: A practical, total synthesis of seco-(+)-oxaduocarmycin 3a, an analogue of the highly cytotoxic natural product, duocarmycin SA (1), is described. The 13-step synthesis features a novel and efficient intramolecular aryl radical cyclization onto a vinyl chloride as a direct entry to the (chloromethyl)indoline alkylating subunit 14. Subsequent resolution, utilizing a preparative Chiralpak AD column, provided enantiomerically pure alkylating subunits 14a and 14b which were elaborated to seco-(+) and ent-(−)-oxaduocarmycins, 3a and 3b, respectively. The natural enantiomer 3a was active at pM concentrations and exhibited 7−50-fold higher potentcy than its enantiomer 3b in in vitro cytotoxicity assays.

Aminoalkanesulphonic acid derivatives, their preparation and their use as medicaments

Abstract: Derivatives of sulphonic aminoalkane acids, corresponding to formula (I) where X is R1, R2 and R3 are selected from hydrogen and a C1-C7 alkyl radical, and A is a group of the formula (e) where v and w are 0, 1, 2 or a group of formula (f) where R5 and R6 are selected independently of each other from hydrogen, a C1-C7 alkyl radical, an aryl radical having between 6 and 14 carbon atoms and a heteroaryl radical; t is 1-3; R4 is selected from hydrogen, a C1-C7 alkyl radical, a CF3 radical, an aryl radical having between 6 and 14 carbon atoms and a heteroaryl radical; M is a monovalent metal (Na, K, Li) or a divalent metal (Ca, Mg, Sr, Zn); m is 1 or 2; p is 1-2 and q is 1-2; and where p and q are such that the electrical neutrality of the salt is ensured. The compounds can be used for the treatment of alcohol dependence.

Method for treating abnormal cell proliferation in the brain

Abstract: This invention relates to a method for treating abnormal cell proliferation in the brain by administering a compound of formula (I) or a pharmaceutically acceptable salt or hydrate thereof: in which R represents a hydrogen atom or an acetyl, alkoxyacetyl or alkyl radical, R1 represents a benzoyl radical or a radical R2-O-CO- wherein R2 represents an alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, bicycloalkyl, phenyl or heterocyclylic radical, and Ar represents an aryl radical.

Base-catalyzed synthesis of 1-aryl-4-(aryl ethyl)piperazines from aromatic olefins and 1-aryl piperazines

Abstract: The invention relates to a method for producing a 1-aryl-4-(aryl ethyl)piperazine of formula (I) by reacting a 1-aryl piperazine of formula (II) with an aromatic olefin of formula (III) Ar'CR1=CHR2 in an inert solvent and in the presence of at least one basic catalyst, whereby in formulas (I) to (III); Ar and Ar', independent of one another, represent an aryl radical selected from the group of the condensed and non-condensed C?6?-C22-aromatic compounds and of the condensed or non-condensed C5-C22-heteroatoms which contain at least one nitrogen, oxygen or sulfur atom in the ring; R1 and R2, independent of one another, represent a hydrogen atom, a C1-C8-alkyl radical or an aryl radical Ar.

Method for obtaining organosilanes using a distribution reaction

Abstract: The invention concerns a method for obtaining organosilanes comprising a redistribution reaction between a chlorinated organohydrogenosilane of formula (1): (R)a(H)bSiCl4-a-b and an organo-substituted and optionally chlorinated silane of formula (2): (R')cSiCl4-c, formulae in which: a = 1 or 2, b = 1 or 2, a + b ≤ 3, c = 1, 2, 3 or 4, symbols R and R' are similar or different and represent each a linear or branched C1-C6 alkyl radical or a C6-C12 aryl radical, said redistribution reaction taking place in the presence of an effective amount of a catalyst based on a metal derivative. Said method is characterised in that the catalyst remains in solid state in the presence of the reacting silanes (1) and (2) and consists of an alumina having a content in alkaline metal M or alkaline-earth metal M', expressed in ppm of M2O or M'O oxide relative to catalyst weight (alumina comprising in particular M or M'), not more than 500 ppm.

Method for producing ruthenium complexes

Abstract: The invention relates to a method of producing ruthenium complexes of general formula (I): RuX2(=CH-CH2R)L1L2, wherein X is an anionic ligand, R is hydrogen or an optionally substituted C?1-20? alkyl radical or C6-20 aryl radical, and L?1 and L2? independently are neutral electron-donor ligands. Said ruthenium complexes are produced by a) reacting RuX?3? with a diene in a solvent on the basis of one or several aliphatic secondary alcohols in the presence of a reducing adjuvant, reacting said mixture with L?1 and L2? in the presence of at least one coordinating weak base and hydrogen and without isolating any intermediates, b) reacting the mixture with compounds of general formula (II): R-C≡CH, wherein R has the meaning indicated above, in the presence of a soluble chloride source.

Method for producing organoalkali-metal compounds

Abstract: The invention relates to a method for producing organoalkali-metal compounds by reacting metal lithium, sodium or potassium with an organic compound containing at least one acid CH bond in a solvent. The inventive method is characterized in that the reaction is carried out in the presence of a hydrogen acceptor, wherein 0.5 to 5 mols of the hydrogen acceptor are used per mol of acid hydrogen which can be replaced by lithium, sodium or potassium, whereby I to 3 mols of lithium, sodium or potassium are used per mol of acid hydrogen and the acid CH bond has a pk a value of 10 to 30. Cyclopentadiene, indene, fluorene and substitution products thereof or mono-substituted alkynes or methane substitution products are used CH acid organic compounds. Hydrocarbons are used as hydrogen acceptors with at least one CC double bond, which are in conjugation with either another CC double bond or with a monocyclic aryl radical.

Cosmetic composition comprising a functionalised polyorganosiloxane

Abstract: The invention concerns a cosmetic composition comprising at least a functionalised organopolysiloxane of formula (I) or (I'): (R?1)(R2)(R3?)Si-O-[Si(R4)(Z)-O]?n?-[Si(R?5)(R6)-O]?m-Si(R?7)(R8)(R9?) where in formula (I), m ranges between 0 and 5, n ranges between 0 and 5, at least one of the radicals R?1 and R9? representing Z when n is equal to 0; in formula (I'), n ranges between 1 and 5, m ranges between 1 and 5, with n+m equal to at least 3; in formulae (I) and (I') R?1 and R9? are identical or different and represent Z or an alkyl radical; R?2, R3, R4, R5, R6, R7 and R8? are identical or different and represent an alkyl radical; Z represents a halogenoaliphatic radical, an -X-Y radical, where X represents a polyvalent aliphatic group and Y represents: an aryl radical optionally substituted by an alkyl, aryl group or a halogen atom; an ethylenically unsaturated cycloaliphatic radical optionally substituted by an alkyl group or a halogen atom; a saturated cycloaliphatic radical optionally substituted by a halogen atom; a hydrocarbon heterocyclic radical containing at least one hetereoatom N and/or O and/or S, radical optionally substituted by an alkyl, aryl group or a halogen atom; said symbol Z further capable of representing a phenyl radical when n+m is equal to 0. Said functionalised organotrisiloxane function is used as emollient and/or carrier and/or anti-transfer agent in cosmetic compositions.

Synthesis and Evaluation of CC‐1065 and Duocarmycin Analogues Incorporating the Iso‐CI and Iso‐CBI Alkylation Subunits: Impact of Relocation of the C‐4 Carbonyl.

Abstract: The synthesis of 2-(tert-Butyloxycarbonyl)-1,2,9,9a-tetrahydrocyclopropa[c]benzo[f]indol-8-one (31, N-BOC-iso-CBI) and 1-(tert-Butyloxycarbonyl)-4-hydroxy-3-[[(methanesulfonyl)oxy]methyl]-2,3-dihydroindole (19, seco-N-BOC-iso-CI) containing an isomeric structural modification in the CC-1065 and duocarmycin alkylation subunits and their incorporation into analogues of the natural products are detailed. The approach was based on a directed ortho metalation of an appropriately functionalized benzene (13) or naphthalene (24) precursor to regiospecifically install iodine at the C-2 position. Conversion of these respective intermediates to the dihydroindole skeleton utilized an established 5-exo-trig aryl radical cyclization onto an unactivated alkene with subsequent TEMPO trap or the more recent 5-exo-trig aryl radical cyclization onto a vinyl chloride for direct synthesis of the immediate precursors. Closure of the activated cyclopropane to complete the iso-CBI nucleus was accomplished by a selective ortho sp...

Phosphine-substituted cobalticinium salts, production thereof, and use of the same as constituents of catalysts

Abstract: The invention relates to phosphine-substituted cobalticinium salts of formula (I), wherein R1 is the same or different and is hydrogen, alkyl- or alkoxy radicals with 1 to 14 carbon atoms, also cycloalkyl-, aryl- or aroxy radicals with 6 to 14 carbon atoms, an anellated benzol ring, an acid amide radical -C(O)-NR2R3, wherein R?2 and R3? are the same or different and represent hydrogen, alkyl radicals with 1 to 14 carbon atoms, cycloalkyl- or aryl radicals with 6 to 14 carbon atoms, the carboxyl group or an ester radical -C(O)-OR4, wherein R4 represents an alkyl radical with 1 to 14 carbon atoms, also a cycloalkyl- or aryl radical with 6 to 14 carbon atoms; n is the same or different and is a whole number between 0 and 4, m is a whole number between 1 and 3, and X is equal to hexafluoroantimonate, tetraphenyl borate, tosylate, tetrafluoroborate, triflate, trifluoroacetate, triiodide, tribromide, nitrate, perchlorate, sulphate, phosphate, sulphonate O-S(O)?2?-R?5, R5? representing an alkyl radical with 1 to 14 carbon atoms, also a cycloalkyl- or aryl radical with 6 to 14 carbon atoms or carboxylate O-(CO)-R6, R6 representing hydrogen, an alkyl radical with 1 to 14 carbon atoms, a cycloalkyl- or aryl radical with 6 to 14 carbon atoms. The invention also relates to a method for producing the inventive phosphine-substituted cobalticinium salts. These compounds are suitable for use as ligands for metal complexes used as catalysts in chemical processes.

Bridged metallocene catalyst having substituent at alpha position

Abstract: PURPOSE: Provided is a bridged metallocene catalyst having a substituent at only alpha position. Also, provided are a synthesis method thereof and a polymerization method of olefin by using the same. CONSTITUTION: A metallocene compound is characterized by the formula(1), wherein M is transition metal of IVb group; Rs are the same or different hydrogen radicals, C1-20 alkyl radical, C1-20 alkenyl radical, C1-20 aryl radical, C1-20 alkyl aryl radical and C1-20 aryl alkyl radical; B is a bridge binding two of cyclopentadienyl ligands, each consisting of C1-4 alkylene radical, C1-C4 dialkyl silicone or germanium, C1-C4 alkylphosphine or amine; and Qs are the same or different halogen radical, C1-20 alkyl radical, C1-20 alkenyl radical, C1-20 aryl radical, C1-20 alkyl aryl radical, C1-20 aryl alkyl radical or C1-20 alkylidene radical.