- Synthesis and Properties of Novel Surface Active Monomers Based on Derivatives of 4-Hydroxybutyric Acid and 6-Hydroxyhexanoic Acid
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Novel surface active maleate and methacrylate monomers based on derivatives of ω-hydroxy carboxylic acids have been synthesized. The monomers are comprised of hydrophobic alkyl chains and hydrophilic poly(ethylene glycol), quaternary ammonium, sulfonate and carboxylic fragments. Synthesized monomers sufficiently reduce surface tension at the aqueous solution-air interface. The copolymerization of synthesized monomers with 5-tert-butylperoxy-5-methyl-2-hexene-3-yne monomer and N-vinylpyrrolidone in solvent and emulsion copolymerization of synthesized peroxide containing surface active monomer with styrene have been carried out. The synthesized surface active monomers have been shown to be suitable emulsifiers for obtaining polystyrene colloid dispersions. It has been ascertained that the surface active copolymers obtained can form stable interpolyelectrolyte complexes with oppositely charged polymers.
- Borzenkov, Mykola,Mitina, Natalia,Lobaz, Volodymyr,Hevus, Orest
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- Boron tribromide as a reagent for anti-Markovnikov addition of HBr to cyclopropanes
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Although radical formation from a trialkylborane is well documented, the analogous reaction mode is unknown for trihaloboranes. We have discovered the generation of bromine radicals from boron tribromide and simple proton sources, such as water ortert-butanol, under open-flask conditions. Cyclopropanes bearing a variety of substituents were hydro- and deuterio-brominated to furnish anti-Markovnikov products in a highly regioselective fashion. NMR mechanistic studies and DFT calculations point to a radical pathway instead of the conventional ionic mechanism expected for BBr3
- Chen, Shuming,Gieuw, Matthew H.,Houk, K. N.,Ke, Zhihai,Yeung, Ying-Yeung
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p. 9426 - 9433
(2020/10/02)
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- Synthesis of polysiloxane-based quaternized imidazolium salts with a hydroxy group at the end of alkyl groups
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A series of polysiloxane derivatives having quaternized imidazolium moieties with hydroxyalkyl groups ([HPImnOH]Xs) (where n is the number of methylene group and X is counter anion) were prepared by quaternization of poly(3-chloropropylmethylsiloxane) (P1) using 1-(ω-hydroxyalkyl)imidazole derivatives (ImnOHs) and anion-exchange reaction using lithium bis(trifluoromethanesulfonyl)imide. Polysiloxane-based quaternized imidazolium salts having hydroxyalkyl groups with chloride anion ([HPImnOH]Cls) were obtained with high quaternization ratio of approximately 100 mol%. The glass transition temperatures (Tgs) of [HPImnOH]Xs were reduced by introducing a hydroxy group at the end of alkyl groups; however, no significant reduction in Tgs was observed by anion exchange from chloride anion to bis(trifluoromethanesulfonyl)imide one (Tf2N-).
- Ichikawa, Tsukasa,Wako, Tsuyoshi,Nemoto, Nobukatsu
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- Building blocks for (C15-C3)-modified epothilone D analogs
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A promising potentially biologically active structure have been designed by isosteric rearrangement of the C15-C3 fragment of epothilone D, and building blocks necessary for its assembly have been synthesized.
- Valeev,Bikzhanov,Miftakhov
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p. 1511 - 1519
(2015/02/02)
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- Design, synthesis and antimycobacterial activities of 1-methyl-2-alkenyl- 4(1H)-quinolones
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A series of 23 new 1-methyl-2-alkenyl-4(1H)quinolones have been synthesized and evaluated in vitro for their antimycobacterial activities against fast growing species of mycobacteria, such as Mycobacterium fortuitum, M. smegmatis and M. phlei. The compounds displayed good to excellent inhibition of the growth of the mycobacterial test strains with improved antimycobacterial activity compared to the hit compound, evocarpine. The most active compounds, which possessed chain length of 11-13 carbons at position-2 displayed potent inhibitory effects with an MIC value of 1.0 mg/L. In a human diploid embryonic lung cell line, MRC-5 cytotoxicity assay, the alkaloids showed weak to moderate cytotoxic activity. Biological evaluation of these evocarpine analogues on the less pathogenic fast growing strains of mycobacteria showed an interesting antimycobacterial profile and provided significant insight into the structure-activity relationships.
- Wube, Abraham A.,Hüfner, Antje,Thomaschitz, Christina,Blunder, Martina,Kollroser, Manfred,Bauer, Rudolf,Bucar, Franz
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experimental part
p. 567 - 579
(2011/03/17)
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- A new one-pot synthetic method for selenium-containing medium-sized α,β-unsaturated cyclic ketones
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The reaction of tetrahydroselenopyran-2-one (7) with ethynyllithiums 20a-h, followed by treatment with aqueous 5% H2SO4 successfully led to a two-carbon ring expansion to give the 2-substituted 5,6,7,8-tetrahydroselenocin-4-ones 21a-h in 43-95% yields. Seven- to nine-membered γ-selena-α,β-unsaturated cyclic ketones 22-26 and a 5,6,7,8-tetrahydrotellurocin-4-one 27 were also prepared from the corresponding selenolactones or tellurolactone in a one-pot reaction.
- Sashida, Haruki,Nakayama, Akemi,Kaname, Mamoru
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experimental part
p. 3229 - 3236
(2009/05/07)
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- Functional group transformations of diols, cyclic ethers, and lactones using aqueous hydrobromic acid and phase transfer catalyst under microwave irradiation
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Synthesis of bromoalkanols has been achieved from diols, ethers, and lactones using aq HBr (48%) and tetrabutylammonium iodide/bromide as phase transfer catalyst under microwave irradiation. This environmentally benign route provides enhanced yields of products and does away with the use of benzene as compared to existing conventional methods.
- Kad, Goverdhan L.,Kaur, Irvinder,Bhandari, Monica,Singh, Jasvinder,Kaur, Jasamrit
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p. 339 - 340
(2013/09/06)
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- Derivatives of quinoline as alpha-2 antagonists
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A compound of formula I, wherein A, Ra, Rb, R1 to R5, m and t are as defined as disclosed, or a pharmaceutically acceptable salt or ester thereof, useful as an alpha-2 antagonist. The compounds I can be used for the treatment of diseases or conditions where alpha-2 antagonists are indicated to be effective.
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- Interhalogen-Catalyzed Cleavages of Ethers and Esters with Trimethylsilyl Bromide or Chloride
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The cleavages of various dialkyl ethers, trimethylsilyl alkyl ethers, and alkyl esters by trimethylsilyl bromide are strongly catalyzed by iodine monobromide.This catalyzed cleavage procedure using iodine monobromide makes possible synthetic applications for trimethylsilyl bromide which were previously ruled out by problems with its low reactivity.Cleavages of benzylic and tertiary alkyl ethers and esters by trimethylsilyl chloride are feasible when catalyzed by iodine monochloride.However, other systems are essentially unreactive toward trimethylsilyl chloride even in the presence of iodine monochloride.
- Friedrich, Edwin C.,DeLucca, George
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p. 1678 - 1682
(2007/10/02)
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- 3-Trehalosamine compounds
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Novel antibiotic 3-trehalosamine (U-59,834) producible in a fermentation under controlled conditions using the new microorganism Nocardiopsis trehalosei sp. nov., NRRL 12026. This antibiotic is active against Gram-positive bacteria, for example, Staphylococcus aureus, Bacillus subtilis, and Diplococcus pneumoniae. Thus, 3-trehalosamine can be used in various environments to eradicate or control such bacteria. Antibiotic 3-trehalosamine can be shown by the following structural formula: STR1
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- SYNTHESIS OF THE TRIETHYL ESTERS OF 1-HALOGENOBUTANE-1,4,4-TRICARBOXYLIC ACIDS
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A method of preparation of triethyl 1-chloro- and 1-bromobutane-1,4,4-tricarboxylate is described.
- Incze, M.,Soti, F.,Szantay, Cs.
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p. 267 - 272
(2007/10/02)
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- Antibiotic 354 and process for producing same
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Novel antibiotic 354 (U-54,703) producible in a fermentation under controlled conditions using the new microorganism Streptomyces puniceus subsp. doliceus, NRRL 11160. This antibiotic is active against Gram-negative bacteria, for example, Pseudomonas and Proteus species. Thus, antibiotic 354 can be used in various environments to eradicate or control such bacteria.
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- Composition of matter and process
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Novel antibiotic formulations of antibiotic 354 (U-54,703) and their use in treating susceptible infectious disease in humans and animals.
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- Cephalosporin derivatives
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New cephalosporin derivatives containing a formyl substituted pyrrole group and the processes for preparing same are described.
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- Aminoglycoside antibiotics
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6-0- AND 3'-0-D-glycosyl analogs of 4-0-(α-D-glycosyl)-2-deoxystreptamine, 6-0- and 3'-0-D-glycosyl ortho esters of 4-0-(α-D-glycosyl)-2-deoxystreptamine, novel aminoglycoside antibiotics, and novel intermediates are prepared by a new chemical process. The compounds have utility as antibacterial agents or as intermediates to make antibacterially-active compounds.
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