- Design and synthesis of a novel corrosion inhibitor embedded with quaternary ammonium, amide and amine motifs for protection of carbon steel in 1 M HCl
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Methyl 11-bromoundecanoate [Br (CH2)10CO2Me] (1) on treatment with tripropylamine gave quaternary salt [Pr3N+(CH2)10CO2Me]Br? (2) which on treatment with diethylenetriamine afforded [Pr3N+(CH2)10CONH(CH2)2NH(CH2)2NH2] Br? (3) containing inhibitive motifs of ammonium, amide and amine motifs embedded in a single frame. The precursor salt 2 and its derivative 3 were successfully synthesized in excellent yields and characterized using different spectroscopic techniques. For the first time, a detailed study on the corrosion inhibition behavior of corrosion inhibitors 2 and 3 for mild steel in 1 M HCl was carried out using electrochemical measurements and comprehensive computational analysis. Both the studied inhibitors showed excellent aqueous solubility. The high inhibition efficiency of 91percent and 93percent at a concentration of 200 mg L?1 was obtained for corrosion inhibitors 2 and 3, respectively. The adsorption of the corrosion inhibitors exhibited the Langmuir isotherm with a mixture of physical and chemical modes of adsorption. The impedance studies showed a rise in the polarization resistance with increasing concentration of the inhibitors. Polarization measurements demonstrated that the inhibitors displayed a mixed-mode of inhibition with primarily cathodic nature. Surface analytical studies supported the inhibitor adsorption and a protective film formation on the carbon steel surface, which improved the surface smoothness of the steel surface. The DFT based quantum chemical calculations supported the experimentally obtained results and showed that the inhibitor 3 displays superior inhibition in comparison to the inhibitor 2. The Monte Carlo simulations revealed higher adsorption energy for the inhibitor 3 compared to 2.
- Alharbi, Bader G.,Ali, Shaikh A.,Aljeaban, Norah A.,Chauhan, Dheeraj Singh,Jafar Mazumder, Mohammad A.,Quraishi, Mumtaz A.
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- Synthesis, characterization, antimicrobial and biofilm inhibitory activities of new N-oxide esters
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Novel N-oxide esters were synthesized from tertiary amine esters, which in turn were obtained from the reaction of 11-bromoundecanoic acid and different alkyl amines. The synthesized N-oxide esters were characterized by fourier transform infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and mass spectral analysis. The synthetic route involved three steps; initially, 11-bromoundecanoic acid was converted into methyl 11-bromoundecanoate, which was further converted into tertiary amine (mono and di) esters by reacting with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl, and dicyclohexyl amine). Finally, the obtained amine esters were converted into N-oxide esters by treating with m-chloroperbenzoic acid. The synthesized N-oxide esters (4a–e) were studied for their antimicrobial and anti-biofilm activities. Among all the synthesized N-oxide esters, compounds 4a and e showed good antimicrobial activity especially towards pathogenic gram-positive bacterial strains with minimum inhibitory concentration values in the range of 7.8–31.2 μg mL?1. The compounds which exhibited antimicrobial activity were also effective in anti-biofilm activity and it was found that the compound 4e exhibited promising biofilm inhibitory activity with IC50 value of 6.4 μg mL?1 against Bacillus subtilis MTCC 121. Further, compound 4e showed increased levels of intracellular reactive oxygen species accumulation, which may be contributing to the bactericidal activity in B. subtilis MTCC 121.
- Yasa, Sathyam Reddy,Kaki, Shiva Shanker,Poornachandra,Kumar, C. Ganesh,Penumarthy, Vijayalakshmi
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- SYNTHESIS AND CONFORMATION OF A BILIRUBIN ANALOG WITH PROPIONIC ACID SIDE CHAINS EXTENDED TO UNDECANOIC ACID
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A lipophilic analog of bilirubin with propionic acid groups replaced by undecanoic acid groups (1), was synthesized from 11-bromo-undecanoic acid.UV-visible and NMR spectroscopic analyses suggest reduced intramolecular H-bonding and a preference for a helical conformation.Molecular dynamics computations predict a global energy minimum for a helical porphyrin-like conformation with unusual distorted structures when H-bonding is invoked.Circular dichroism of the pigment complex with human serum albumin gives a bilirubin-like bisignate Cotton effect: Δεmax449 = + 33, Δεmax396 = 47.
- Chiefari, John,Person, Richard V.,Lightner, David A.
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- BRANCHED CHAIN MONO-GLYCEROL ETHERS FROM A TAIWANESE MARINE SPONGE OF THE GENUS Aaptos
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3-(13-Methylhexadecyloxy)-1,2-(S)-propanediol (6) and 3-(15-methyloctadecyloxy)-1,2-(S)-propanediol (7) were isolated from Aaptos species of marine sponge from Taiwanese waters and characterized by spectroscopic methods.Homolog 6 was independently synthesized.
- Do, Muu N.,Erickson, Karen L.
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- Synthesis, characterization, antimicrobial and biofilm inhibitory studies of new esterquats
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Novel esterquats (monoesterquats and diesterquats) were synthesized from 11-bromo undecanoic acid (11-BUA) and different alkyl amines. The prepared compounds were characterized by FT-IR, 1H NMR, 13C NMR and mass spectral analysis. 11-BUA was converted into methyl 11-bromo undecanoate which was further converted into amine ester (amine monoester and diester) by reacting with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl and dicyclohexyl amine). Finally, the obtained amine esters were converted into esterquats (monoesterquat and diesterquat) by reacting with methyl iodide followed by ion exchange to afford chloride counter ion esterquats (5a-h). The synthesized esterquat products were studied for their antimicrobial and biofilm inhibitory activities. Among all the compounds, amine ester 3a and esterquat 5d showed potent antimicrobial activity towards pathogenic Gram-positive bacterial strains with minimum inhibitory concentration (MIC) values in the range of 3.9-15.6 μg mL-1 and 1.9-7.8 μg mL-1, respectively. The esterquat 5d also showed promising antifungal activity against Candida albicans MTCC 3017, Candida albicans MTCC 4748 and Candida aaseri MTCC 1962 strains with MIC value of 7.8 μg mL-1 which was identical to standard Miconazole. The compounds which exhibited antimicrobial activity were also effective in anti-biofilm activity and it was found that compound 5d exhibited excellent biofilm inhibitory activity with IC50 value of 0.9 μg mL-1 against Staphylococcus aureus MLS16 MTCC 2940.
- Yasa, Sathyam Reddy,Kaki, Shiva Shanker,Poornachandra,Kumar, C. Ganesh,Penumarthy, Vijayalakshmi
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- Synthesis, characterization, antimicrobial and anti-biofilm activity of a new class of 11-bromoundecanoic acid-based betaines
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Novel betaines were synthesized from esterquats, which in turn were obtained from the reaction of 11-bromo undecanoic acid, different alkyl amines, and methyl iodide. The synthesized betaines were characterized by fourier transform infrared, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance, and mass spectral analysis. These betaines were synthesized in four steps; in the first step, 11-bromo undecanoic acid was converted into methyl 11-bromoundecanoate followed by the synthesis of secondary amine monoester, and tertiary amine mono and diesters by the reaction of 11-bromoundecanoate with different aliphatic amines (hexyl, dodecyl, octadecyl, dioctyl, and dicyclohexyl amine). In the third step, the prepared secondary amine monoesters, tertiary amine mono, and diesters were converted into monoesterquats and diesterquats by reacting with methyl iodide. The resultant esterquats were converted into betaines by saponification reaction using LiOH.H2O in water and tetrahydrofuran. The synthesized compounds (5a–h) were studied for their antimicrobial activity. Some of the compounds showed good to moderate antibacterial activity with minimum inhibitory concentration values ranging between 3.9–31.2 μg mL?1 and antifungal activity with minimum inhibitory concentration values ranging between 7.8–62.4 μg mL?1. Further, some of the betaines also showed good anti-biofilm activity with IC50 values ranging between 2.1–25.3 μg mL?1 on the tested pathogenic microbial and fungal strains.
- Yasa, Sathyam Reddy,Poornachandra,Kumar, C. Ganesh,Penumarthy, Vijayalakshmi
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- Studies in Lipid Mimics. Synthesis and Carbon-13 Relaxation Time Measurements (T1 Values) of Methyl Esters of ω-(2-Anthryl)alkanoic Acids
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The syntheses of methyl 12-(2-anthryl)dodecanoate, methyl 14-(2-anthryl)tetradecanoate, and methyl 17-(2-anthryl)heptadecanoate have been achieved.Both 1H and 13C chemical shifts and T1 values for carbons in the systems have been recorded.By using selected heteronuclear decoupling and performing heteronuclear correlated 2-dimensional (HETCOR-2-D) experiments, it was possible to assign protons to specific carbons in most cases.
- Waugh, Kristy M.,Berlin, K. Darrell
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- IDEBENONE COMPOUNDS
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The present application provides idebenone derivatives or analogues useful for treating a disease or disorder in a subject in need thereof. Pharmaceutical compositions comprising the compounds and methods of treating the disease or disorder are also provided.
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Page/Page column 50
(2021/10/22)
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- Expansion of the structure-activity relationship of branched chain fatty acids: Effect of unsaturation and branching group size on anticancer activity
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Branched chain fatty acids (BCFAs) are a class of fatty acid with promising anticancer activity. The BCFA 13-methyltetradecanoic acid (13-MTD) inhibits tumour growth in vivo without toxicity but efficacy is limited by moderate potency, a property shared b
- Rawling, Tristan,Roseblade, Ariane,Roy, Ritik
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- Total Synthesis of Emmyguyacins A and B, Potential Fusion Inhibitors of Influenza Virus
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Fungal glycolipids emmyguyacins A and B inhibit the pH-dependent conformational change of hemaglutinin A during replication of the Influenza virus. Herein, we report the first total synthesis and structure confirmation of emmyguyacins A and B. Our efficient route, which involves regioselective functionalization of trehalose, allows rapid access to adequate amounts of chemically pure emmyguyacin analogues including the desoxylate derivatives for SAR studies.
- Jana, Santanu,Sarpe, Vikram A.,Kulkarni, Suvarn S.
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p. 6938 - 6942
(2018/10/25)
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- The 4-N-acyl and 4-N-alkyl gemcitabine analogues with silicon-fluoride-acceptor: Application to 18F-Radiolabeling
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The coupling of gemcitabine with functionalized carboxylic acids using peptide coupling conditions afforded 4-N-alkanoyl analogues with a terminal alkyne or azido moiety. Reaction of 4-N-tosylgemcitabine with azidoalkyl amine provided 4-N-alkyl gemcitabin
- Gonzalez, Cesar,Sanchez, Andersson,Collins, Jeffrey,Lisova, Ksenia,Lee, Jason T.,Michael van Dam,Alejandro Barbieri,Ramachandran, Cheppail,Wnuk, Stanislaw F.
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supporting information
p. 314 - 324
(2018/02/21)
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- An enzymatic approach to bifunctional chelating agents
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Bifunctional chelating agents (BFCAs) combine the complexing properties of a multidentate ligand with the presence of a free reactive functional group, mainly devoted to conjugation purposes. Indeed, products obtained by conjugation of a BFCA to a biomolecule and coordination of a suitable metal ion are widely applied in medicine nowadays as diagnostic and therapeutic agents. BFCAs are generally prepared through multi-step syntheses and with extensive application of protection-deprotection strategies, due to the large number of functional groups involved. Hydrolytic enzymes, with their unique chemoselectivity, provided the best results in the preparation of three different BFCAs based on very useful and well known ligand platforms. This journal is the Partner Organisations 2014.
- Minazzi, Paolo,Lattuada, Luciano,Menegotto, Ivan G.,Giovenzana, Giovanni B.
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p. 6915 - 6921
(2014/10/15)
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- Synthesis and cytostatic evaluation of 4-N-alkanoyl and 4-N-alkyl gemcitabine analogues
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The coupling of gemcitabine with functionalized carboxylic acids (C9-C13) or reactions of 4-N-tosylgemcitabine with the corresponding alkyl amines afforded 4-N-alkanoyl and 4-N-alkyl gemcitabine derivatives. The analogues with a terminal hydroxyl group on the alkyl chain were efficiently fluorinated under conditions that are compatible with protocols for 18F labeling. The 4-N-alkanoylgemcitabines showed potent cytostatic activities in the low nanomolar range against a panel of tumor cell lines, whereas cytotoxicity of the 4-N-alkylgemcitabines were in the low micromolar range. The cytotoxicity for the 4-N-alkanoylgemcitabine analogues was reduced approximately by 2 orders of magnitude in the 2′-deoxycytidine kinase (dCK)-deficient CEM/dCK - cell line, whereas cytotoxicity of the 4-N-alkylgemcitabines was only 2-5 times lower. None of the compounds acted as efficient substrates for cytosolic dCK; therefore, the 4-N-alkanoyl analogues need to be converted first to gemcitabine to display a significant cytostatic potential, whereas 4-N-alkyl derivatives attain modest activity without measurable conversion to gemcitabine.
- Pulido, Jesse,Sobczak, Adam J.,Balzarini, Jan,Wnuk, Stanislaw F.
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supporting information
p. 191 - 203
(2014/02/14)
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- Synthesis of donor-σ-perylenebisimide-acceptor molecules having PEG swallowtails and sulfur anchors
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Donor-σ-Acceptor (D-σ-A) molecules, arrayed in a monolayer between electrodes, can serve as molecular rectifiers. Using perylene-3,4,9,10-tetracarboxylic bisimide (PBI) as the acceptor allows the attachment of the donor group to one imide nitrogen and a solubilizing swallowtail, normally a long (e.g., C19) alkane connected at midchain, on the other. Such an alkyl tail facilitates the formation of Langmuir-Blodgett (LB) monolayers. We have employed several modified swallowtails to make new D-σ-A molecules: poly(ethylene glycol) (PEG) swallowtails with 6 ether oxygens or with 4 ether oxygens to promote hydrophilicity in orienting LB monolayers, and alkyl swallowtails ending with sulfur anchors (thioacetate, thiol, or methyl disulfide) to stabilize attachment of the D-σ-A molecules to gold electrodes. The preparation and characterization of D-σ-A molecules containing combinations of these swallowtails with pyrene, ferrocene, and tetramethylphenylenediamine donor groups is described.
- Kota, Rajesh,Samudrala, Ramakrishna,Mattern, Daniell Lewis
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p. 9641 - 9651
(2013/01/15)
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- A photoirradiative phase-vanishing method: Efficient generation of HBr from alkanes and molecular bromine and its use for subsequent radical addition to terminal alkenes
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A triphasic phase-vanishing (PV) system comprised of an alkane, perfluorohexanes, and bromine was successfully combined by photoirradiation to efficiently generate hydrogen bromide, which underwent radical addition with 1-alkenes in the hydrocarbon layer to afford terminal bromides in high yields. Georg Thieme Verlag Stuttgart.
- Matsubara, Hiroshi,Tsukida, Masaaki,Ishihara, Daisuke,Kuniyoshi, Kenji,Ryu, Ilhyong
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experimental part
p. 2014 - 2018
(2010/10/02)
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- First syntheses of model long-chain trichloro[ω-(trimethylsilyl)alkynyl]silanes suitable for self-assembled monolayers on silicon surfaces
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The preparation of the title compounds involves the introduction of the required Me3SiC{triple bond, long}C and trichlorosilyl groups at the termini of the alkyl chain via derivatization of easily accessible and inexpensive materials/reagents. Trichloro[ω-(trimethylsilyl)alkynyl]silanes are useful for the linkage to a hydroxylated silicon surface for multilayer formation and for further chemical modification of the tail group of the monolayer.
- Banaszak, Estelle,Xu, Li-Wen,Bardeau, Jean-Fran?ois,Castanet, Anne-Sophie,Mortier, Jacques
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experimental part
p. 3961 - 3966
(2009/09/30)
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- Bioactive molecular sheets from self-assembly of polymerizable peptides
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We have demonstrated that polymerizable peptides self-assemble into a unique sheet-like 2D structure in bulk solution that can be covalently fixed to produce 2D molecular objects which were shown to be efficient at delivering cargos into living cells and are nearly nontoxic in contrast to non-polymerized nanostructures. The Royal Society of Chemistry.
- Moon, Kyung-Soo,Lee, Eunji,Lim, Yong-Beom,Lee, Myongsoo
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supporting information; experimental part
p. 4001 - 4003
(2009/03/11)
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- COMPOUNDS AND FORMULATIONS SUITABLE FOR RADICAL SCAVENGING
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The present invention relates to compositions and methods of using free radical scavengers with reduced 1O2 generation. In certain embodiments, these compositions and methods of use relate to fullerene-derived ketolactams and fullere
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(2008/12/06)
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- Hybridization of thiol-functionalized poly(phenylacetylene) with cadmium sulfide nanorods: Improved miscibility and enhanced photoconductivity
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Molecules of a thiol-functionalized phenylacetylene derivative were assembled on the CdS nanorod surface and copolymerized with phenylacetylene, affording an inorganic semiconductor-conjugated polymer hybrid with excellent solubility and high photoconduct
- Xu, Hai-Peng,Xie, Bo-Yu,Yuan, Wang-Zhang,Sun, Jing-Zhi,Yang, Feng,Dong, Yong-Qiang,Qin, Anjun,Zhang, Shuang,Wang, Mang,Tang, Ben Zhong
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p. 1322 - 1324
(2007/12/27)
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- Synthesis of trans-vaccenic acid and cis-9-trans-11-conjugated linoleic acid
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The preparation of the monounsaturated fatty acid, trans-vaccenic acid 4 (TVA), using both Wittig and one-pot Julia-Kocieński olefination protocol, was achieved in good yield. Similarly a Wittig approach was employed for the stereoselective synthesis of cis-9-trans-11-conjugated linoleic acid 2 from trans-2-nonenal and (8-carboxyoctyl)triphenylphosphonium bromide 12.
- Duffy, Patricia E.,Quinn, Sonia M.,Roche, Helen M.,Evans, Paul
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p. 4838 - 4843
(2007/10/03)
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- Synthesis of phosphonic acids with the semicarbazide group for the functionalization of metal oxide mid zeolite nanoparticles
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The syntheses of two phosphonic acids possessing the Fmoc-protected semicarbazide group are described. The key step was the Curtius rearrangement, performed in the presence of dibenzyl phosphonate esters. Preliminary experiments showed that the phosphonic acid can be grafted at the surface of oxide nanoparticles and colloidal zeolite nanocrystals, without deprotection of the Fmoc group.
- Doussineau, Tristan,Durand, Jean-Olivier,Granier, Michel,Sma?hi, Monique,Valtchev, Valentin
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p. 1735 - 1738
(2007/10/03)
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- Amino acid-containing polyacetylenes: Synthesis, hydrogen bonding, chirality transcription, and chain helicity of amphiphilic poly(phenylacetylene)s carrying L-leucine pendants
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L-Leucine-phenylacetylene adducts 6 and 14 undergo self-association in concentrated solutions and heterocomplexation with solvent molecules through hydrogen bond formation. The adducts are polymerized by rhodium catalysts into poly(4-ethynylbenzoyl-L-leuc
- Cheuk, Kevin K.L.,Lam, Jacky W.Y.,Chen, Junwu,Lai, Lo Ming,Tang, Ben Zhong
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p. 5947 - 5959
(2007/10/03)
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- New ω-phthalimidoperoxyalkanoic acids in decontamination. Destruction of some toxic organophosphorus and organosulfur pollutants
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Chemical decontamination of toxic compounds (chemical warfare agents and/or insecticides) is of increasing importance. In this study, we report the use of ω-phthalimidoperoxyalkanoic acids 2 in the destruction of paraoxon (O,O-diethyl-O-para-nitrophenylphosphate), a well-known insecticide, and 2-chloro-2′-phenyldiethyl sulfide (a half mustard). We show that while all the peroxyacids used in this series allow the destruction of toxic compounds, the length n of the alkanoic side chain is important to the choice of the optimal industrial compound, which is 2d (n = 5).
- Lion,Da Conceicao,Delmas,Magnaud
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p. 1182 - 1184
(2007/10/03)
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- The synthesis of 14-membered macrocyclic ethers
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As part of an ongoing study of the chemistry of macrocyclic compounds, 14-membered macrocyclic ethers with a variety of methyl substitution patterns were synthesized. The preparation of these macrocyclic ethers involved either the Baeyer-Villiger ring expansion of a cyclic ketone, or the macrolactonization of a hydroxy acid to give a lactone. The lactone carbonyl was removed either by conversion to an intermediate thionolactone obtained by reaction with Lawesson's reagent and reduction, or by direct reduction using a boron trifluoride etherate mediated sodium borohydride reaction.
- Clyne, Dean S.,Weiler, Larry
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p. 13659 - 13682
(2007/10/03)
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- Porphyrin receptors for amines, amino acids, and oligopeptides in water
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A series of water-soluble porphyrin receptors having a hydrophobic binding pocket, a Lewis acidic site (Zn), and an electrostatic recognition site (COO- groups) were prepared. All the porphyrin receptors have a [meso- tetrakis(p-carboxyphenyl)porphyrinato]zinc (Zn·TCPP) as a common structural unit, and eight ω-carboxyalkyloxy groups (alkyloxy = methoxy (1), butoxy (2), decyloxy (3)) at the ortho positions of the phenyl groups. These receptors bind amines, α-amino acid esters, and oligopeptides in water with significant selectivity. For binding of hydrophilic guests, 1, 2, and 3 bind histamine in pH 8 buffer at 25 °C with binding constants of 157000, 31000, and 18200 M-1, respectively, where the coordination (Imd-Zn) and the salt bridge (NH3+--OOC) stabilized the complex. The large dependence of the binding constants on the ionic strength indicated that the electrostatic interaction between the ammonium group of histamine and the carboxylate groups of receptor contributes significantly to tight binding in water. Receptors 1-3 also bind a cationic guest, Arg-OMe, with a binding constant of 440-11000 M-1. The effective charge of the receptors for electrostatic recognition of Arg-OMe in pH 9 Borax (1 = 0.1 M) at 25 °C was evaluated by the Debye-Huckel limiting law as 4.2, 4.3, and 3.0 for 1, 2, and 3, respectively. These observations indicate that a salt bridge, which is exposed to water and involves hydrogen bonding, as seen in the 1-histamine and 1-Arg-OMe complexes, can be used as a significant recognition force. Binding of Arg-OMe by 2 and 3 was entropically driven, and binding of Arg-OMe by 1 was enthalpically driven. Therefore, the driving force of binding is desolvation from the ionic groups in the former case and the electrostatic attraction in the latter case. For binding of hydrophobic guests, 3 binds Trp-OMe or pyridine in water with binding constants of 7000-8000 M-1, while 1 and Zn·TCPP bind these guests less tightly with binding constants of 20- 500 M-1, indicating the importance of the long alkyl chains to provide a hydrophobic binding pocket above the porphyrin plane.
- Mizutani, Tadashi,Wada, Kenji,Kitagawa, Susumu
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p. 11425 - 11431
(2007/10/03)
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- Studies of the topography of biomembranes: the four-step synthesis of a photoactivatable transmembrane phospholipidic probe and its dideuterated analogue
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A convenient method for the synthesis of a dipolar transmembrane phospholipid 1a, which would be a useful photolabelling probe for the study of the topography of sterols of proteins in biomembranes, is described.Starting from 4,4'-dihydroxybenzophenone 13, 1a was synthesized in 4 steps in 31percent total yield.The final, key step, acylation of lysophosphatidylcholine-cadmium chloride complex (4), was achieved using cesium fluoride as a catalyst in DMF.The preparation of the dideuterated 1b or diiodinated 1c analogues is also described.The reaction scheme presented here can also be used for the synthesis of a spin label, a fluorescence label, or a label carrying a high specific radioactivity.Keywords: photolabelling / transmembrane probe / topography / biomembrane / phospholipid bilayer
- Yamamoto, Masakuni,Dolle, Valerie,Warnock, William,Diyizou, Yvonne,Yamada, Masashi,et al.
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p. 317 - 329
(2007/10/02)
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- Synthesis and Solid-State Polymerization of ω-(1,3-Butadiynyl) Substituted 1-Alkanol and Alkanoic Acid
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ω-(1,3-Butadiynyl) substituted 1-alkanol and alkanoic acid were synthesized and their polymerization behavior in crystals and in Langmuir-Blodgett (LB) films were investigated.Polymerization, using UV or γ-ray irradiation or thermal treatment, resulted in red- or golden-colored polymers.Since the absorption edge in the visible spectra of these polymers appeared at shorter wavelengths than those of the well known blue-colored polydiacetylenes, ?-conjugation is considered to be deteriorated to some extent.IR, X-ray diffraction, and solid-state 13C NMR measurements showed that the polymerization does not proceed in a single-crystal-to-single-crystal transition manner via regular 1,4-addition but with deterioration of the crystalline lattice.
- Okada, Shuji,Matsuda, Hiro,Otsuka, Masaaki,Kikuchi, Naoto,Hayamizu, Kikuko,et al.
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p. 455 - 461
(2007/10/02)
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- Method for labeling proteins with technetium or rhenium
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The invention relates to a method for labeling substances with--in particular radioactive--technetium or rhenium isotopes with the aid of N-substituted or C-substituted macrocyclic amine derivatives of the formula I and/or II STR1 in which R1 -R7, Y, m, n, o, p, f, g, h, i and j have the stated meanings, and to the use of these labeled substances, especially in medical diagnosis.
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- Difluoroalkane and difluoroalkenylalkane pesticides
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The present invention discloses compounds of the formula STR1 in which R is a 1,1-difluoroalkyl group or a 1,1-difluoroethenyl group having an even numbered carbon chain length of from 4 to 22 carbon atoms, pesticidal compositions thereof; and their use to control plant pests such as insects, acarids, and nematodes.
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- ORGANOBORANES FOR SYNTHESIS. 10. THE BASE-INDUCED REACTION OF BROMINE WITH ORGANOBORNES. A CONVENIENT PROCEDURE FOR THE CONVERSION OF ALKENES INTO ALKYL BROMIDES VIA HYDROBORATION
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The reaction of trialkylboranes with bromine is greatly accelerated by base.Bromination in the presence of sodium hydroxide provides alkyl bromide along with a large amount of the corresponding alcohol.The use of sodium methoxide as a base eliminates this undesirable side reaction and provides an improved yield of alkyl bromide.Consequently, hydroboration, followed by bromination in the presence of sodium methoxide, provides a convenient new procedure for the conversion of alkenes into alkyl bromides.The organoboranes, obtained via hydroboration of terminal alkenes, react with the utilization of all three alkyl groups attached to boron, providing nearly quantitative yields of alkyl bromides. This procedure also accommodates common organic functional groups, as demonstrated by the preparation of methyl 11-bromoundecanoate and 11-bromoundecyl acetate from the corresponding functionally substituted alkenes.Under these conditions, secondary and bulky primary alkyl groups react more sluggishly.However, a procedure involving simultaneous addition of bromine and methanolic sodium methoxide provides improved results for such derivatives.Surprisingly, the base-induced bromination of tri-exo-nobornylborane results in an inversion of configuration at the reaction center to give predominantly endo-2-bromonorbornane.A mechanism is proposed to account for this remarkable inversion.
- Brown, Herbert C.,Lane, Clinton F.
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p. 2763 - 2772
(2007/10/02)
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- Synthese de lactones a cycle moyen: Application a la synthese du pentadecanolide-15 et du phoracantholide I
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Medium ring size lactones can be prepared from bifunctional commercial starting compounds in high yields, using a few step sequence.Lactonisation is obtained by cyclization of the free ω-hydroxyacids or by the cyclization of ω-hydroxyacids having the hydroxy and carboxy group protected.
- Cossy, Janine,Pete, Jean-Pierre
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p. 989 - 994
(2007/10/02)
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- Glycosides
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An O-glycoside having the general formula: wherein Hal is chlorine, bromine or iodine, m is an integer of 2-20 inclusive and n is an integer of 1 to 10, inclusive, with the proviso that when n=1 and m=2, the aldose is different from glucose; An O-glycosid
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- Synthesis from pullulan of spacer-arm, lipid, and ethyl glycosides of a tetrasaccharide [alpha-D-Glc-(1----6)-alpha-D-Glc-(1----4)-alpha-D-Glc-(1----4)-D-Glc] found in human urine; preparation of neoglycoproteins.
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Enzymic hydrolysis of pullulan, followed by acetylation and chromatography, gave acetylated alpha-D-Glcp-(1----6)-alpha-D-Glcp-(1----4)-alpha-D-Glcp-(1----4)-D-Glcp which, with 2-bromoethanol and boron trifluoride etherate in dichloromethane, gave the 2-bromoethyl glycoside. The reactions of the glycoside with methyl 3- mercaptopropionate , methyl 11- mercaptoundecanoate , and octadecanethiol are described, and also its hydrogenolysis to give an ethyl glycoside. The mercaptopropionate -derived, spacer-arm glycoside has been coupled to bovine serum albumin and keyhole limpet haemocyanin.
- Dahmen,Frejd,Magnusson,Noori,Carlstroem
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- SYNTHESIS OF 1,44-TETRATETRACONTANEDIOL
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The synthesis of the long-chain aliphatic diol 1,44-tetratetracontanediol was realized by chain growth in the Wurtz reation.Twofold condensation of the bifunctional fragments led to 1,44-tetratetracontanediol.Halogen-containing alcohols with protecting tetrahydrofuranyl and trimethylsilyl groups were used as starting compounds for the Wurtz condensation.
- Rusanova, E. E.,Sebyakin, Yu. L.,Volkova, L. V.,Evstigneeva, R. P.
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p. 248 - 251
(2007/10/02)
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- Orthocarbonsaeure-ester mit 2,4,10-Trioxaadamantanstruktur als Carboxylschutzgruppe; Verwendung zur Synthese von substituierten Carbonsaeuren mit Hilfe von Grignard-Reagenzien
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The surprising stability of 2,4,10-trioxa-3-adamantyl derivatives 1 against nucleophilic substitution by organomagnesium compounds is discussed and shown to be caused by unfavourable stereoelectronic and steric factors governing the substitution of these cage compounds (Scheme 2).As a consequence, a number of Grignard reagents 2 containing the carboxyl group masked as 2,4,10-trioxa-3-adamantyl group could be prepared and have been reacted in a second step with various electrophiles (cf.Scheme 4).In the products 7-13 and 15b the carboxyl masking group is removed by mild ac id hydrolysis and saponification (cf.Scheme 3) to yield the corresponding acids 16a-21a, 22, and 23a.Acids 21a and 23a have been further transformed to give the macrocyclic lactones 24 and 26, isolated from Galbanum oleo-gum-resin, and acid 22 to give 12-methyl-13-tridecanolide (25), isolated from Angelica root oil.In addition 1-bromo-ω-(2,4,10-trioxa-3-adamantyl)alkanes 1c and 1b have been used to synthesize (+/-)-methyl recifeiolate (29b) and pure cis-ambrettolic acid ((Z)-32a).
- Voss, Gundula,Gerlach, Hans
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p. 2294 - 2307
(2007/10/02)
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- Facile Conversion of Alkenes into Alkyl Bromides via Reaction of Organoboranes with Bromine or Bromine Chloride
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Organoboranes react with either bromine or bromine chloride in aqueous media to yield the corresponding alkyl bromides under surprisingly mild conditions.The reaction is ideal for the synthesis of functionally substituted organic bromides.Sodium bromide may be utilized as the bromine source via its in situ conversion to bromine chloride by using mild oxidizing agents.
- Kabalka, George W.,Sastry, Kunda A. R.,Hsu, Henry C.,Hylarides, Mark D.
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p. 3113 - 3115
(2007/10/02)
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- INSECT PHEROMONES AND THEIR ANALOGS III. SYNTHESIS OF THE SEX ATTRACTANTS OF SOME LEPIDOPTERA
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A new route to the synthesis of a number of attractants of Lepidoptera (Argyrotaenia velutinana, Mamestra configurata, and Lycorea ceres ceres) have been developed.These substances are acetates of enols with the cis configuration: tetradec-11-en-1-ol, hexadec-11-en-1-ol, and octadec-11-en-1-ol, respectively.The constants of the substances obtained agree completely with those given in the literature.The method is based on the coupling of the C3, C5, and C7 aldehydes with methyl 11-bromoundecanoate (I) by the Wittig reaction.To obtain compound (I) from methyl undeca-2E,5E,10-trienoate or methyl undeca-10-enoate we used hydroboration according to Brown followed by hydrogenation and bromination of the alcohol obtained.The advantage of this method is the use as starting materials of esters of unsaturated acids readily obtained by the homogeneous catalytic co-oligomerization of 1,3-dienes with acrylates.
- Dzhemilev, U. M.,Balezina, G. G.,Volkova, L. A.,Krivonogov, V. P.,Tolstikov, G. A.
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