- Soft antimicrobial agents: Synthesis and activity of labile environmentally friendly long chain quaternary ammonium compounds
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A series of soft quaternary ammonium antimicrobial agents, which are analogues to currently used quaternary ammonium preservatives such as cetyl pyridinium chloride and benzalkonium chloride, were synthesized. These soft analogues consist of long alkyl chain connected to a polar headgroup via chemically labile spacer group. They are characterized by facile nonenzymatic and enzymatic degradation to form their original nontoxic building blocks. However, their chemical stability has to be adequate in order for them to have antimicrobial effects. Stability studies and antibacterial and antiviral activity measurements revealed relationship between activity, lipophilicity, and stability. Their minimum inhibitory concentration (MIC) was as low as 1 μg/mL, and their viral reduction was in some cases greater than 6.7 log. The structure-activity studies demonstrate that the bioactive compounds (i.e., MIC for Gram-positive bacteria of 10μg/mL) have an alkyl chain length between 12 and 18 carbon atoms, with a polar headgroup preferably of a small quaternary ammonium group, and their acquired inactivation half-life must be greater than 3 h at 60 °C.
- Thorsteinsson, Thorsteinn,Másson, Már,Kristinsson, Karl G.,Hjálmarsdóttir, Martha A.,Hilmarsson, Hilmar,Loftsson, Thorsteinn
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- C(sp3)-H Activation without a Directing Group: Regioselective Synthesis of N-Ylide or N-Heterocyclic Carbene Complexes Controlled by the Choice of Metal and Ligand
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N-Ylide complexes of Ir have been generated by C(sp3)-H activation of α-pyridinium or α-imidazolium esters in reactions with [Cp?IrCl2]2 and NaOAc. These reactions are rare examples of C(sp3)-H activation withou
- Cross, Warren B.,Razak, Sunnah,Singh, Kuldip,Warner, Andrew J.
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- Acidification corrosion inhibitor based on interpolymer indolizine derivative as well as preparation method and application thereof
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The invention discloses an acidification corrosion inhibitor based on an interpolymer indolizine derivative as well as a preparation method and application thereof. The acidification corrosion inhibitor contains the interpolymer indolizine derivative; the interpolymer indolizine derivative is prepared by carrying out decarboxylation on heterocyclic alkali including (substituted) quinoline, (substituted) pyridine and the like, and carboxymethyl heterocyclic alkali quaternary ammonium salt obtained by alpha-haloacetic acid, and then carrying out intermolecular addition polymerization reaction onquaternary ammonium salt of the heterocyclic alkali including the (substituted) quinoline, the (substituted) pyridine and the like. The acidification corrosion inhibitor disclosed by the invention has relatively good corrosion inhibition performance under the condition that common corrosion inhibition synergists including alkynol and the like do not need to be compounded; the use amount of the acidification corrosion inhibitor is less and the acidification corrosion inhibitor can reach, even be better than the requirements of an acidification corrosion inhibitor performance testing method andfirst-grade to third-grade standards in evaluation indexes SY/T 5405-1996 when being independently used.
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Paragraph 0032
(2018/09/12)
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- 1,3-Dipolar cycloaddition of azinium ylides to alkynyl hetarenes: A synthetic route to indolizine and pyrrolo[2,1-a]isoquinoline based heterobiaryls
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For the first time, π-deficient alkynyl hetarenes were used as dipolarophiles in a 1,3-dipolar cycloaddition reaction with in situ generated azinium ylides. A three-component reaction of pyridine or isoquinoline, ethyl chloroacetate and alkynyl hetarene (
- Nelina-Nemtseva, Julia I.,Gulevskaya, Anna V.,Pozharskii, Alexander F.,Nguyen, Huong T.L.,Filatova, Ekaterina A.
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p. 2327 - 2335
(2016/04/19)
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- Deprotonation of 1-(carbethoxyalkyl)pyridinium halides with strong N-bases
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The rate constants were measured for deprotonation of 1-(carbethoxymethyl)pyridinium chloride and 1-(2-carbethoxyethyl)pyridinium bromide with strong bases (DBU, MTBD, TBD and P2-Et) in acetonitrile. The UV spectra and semiempirical calculations are consistent with an ylide structure of the deprotonated species. The ylides obtained slowly decompose, and the reaction products were identified by 1H NMR spectroscopy; 1-(carbethoxymethyl)pyridinium chloride gives N-methylpyridinium cation and ethanol and 1-(2-carbethoxyethyl)pyridinium bromide converts to pyridine and ethyl acrylate. Copyright
- Dega-Szafran, Zofia,Schroeder, Grzegorz,Szafran, Miroslaw
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- Process for the preparation of pyridinium intermediates
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A process for the preparation of halobenzoic acids, comprising the step of reacting a halonitrobenzene with a pyridinium salt to form an intermediate of the formula STR1 wherein R is selected from the group consisting of hydrogen, alkyl, aryl, alkenyl, alkynyl, --CN, --COOR' and --COR' where R' is alkyl or aryl; X is chloro or fluoro; Y is hydrogen, chloro or fluoro; and Z is chloro, bromo or iodo.
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- Ba(OH)2 AS CATALYST IN ORGANIC REACTIONS - PART XIX - STRUCTURE-CATALYTIC ACTIVITY RELATIONSHIP IN THE AdN OF SEVERAL YLIDS TO CH=O GROUP, CATALYZED BY ACTIVATED BARIUM HYDROXIDE CATALYST
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The reactivity of several products R1R2CH-X(1+), 1, (X=N,P,S), which can produce ylids by reaction with bases, has been tested using the activated barium hydroxide catalysts, C-200.Wittig-Horner, Wittig, Corey-Chaykovsky and Kroehnke type reactions have been analyzed.The pKa of 1, and the structure of active sites control the process.When 1 has a strong acid character, the process takes place - dissolving the solid - in homogeneous phase.When 1, has pKa values 11.7), that control the reaction mechanism and the reactivity of adsorbed ylids.
- Sinisterra, J. V.,Marinas, J. M.,Riquelme, F.,Arias, M. S.
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p. 1431 - 1440
(2007/10/02)
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