- Co(II) complexes derived from (1-methyl-1H-imidazol-2-yl)methanol: Synthesis, characterization, spectroscopic study, DFT/TD-DFT calculations and biological evaluation
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We report in this paper, a combined experimental and theoretical study of two new Co(II) complexes [Co(OAc)2(L)2 (1) and CoCl2(L)2 (2)] based on (1-methyl-1H-imidazol-2-yl)methanol (L). The synthetized complexes were characterized by single-crystal X-ray diffraction, FT-IR and UV–Vis. spectroscopy. In complex 1, two molecules of L are coordinated to the Co(II) ion in bidentate mode through the nitrogen and oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in complex 2, L is ligated to the metal ion in monodentate fashion through the nitrogen atom exhibiting a distorted tetrahedron. The molecular geometries, electronic transitions and vibrational frequencies of the two complexes and L in the ground state were calculated using the global hybrid (B3LYP) and the range separated hybrid (CAM-B3LYP) density functional. The theoretical calculations are in good agreement with the experimental values. The ligand and its Co(II) complexes have been screened and evaluated for their potential as DPPH radical scavengers as well as antimicrobial agents against five pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, a yeast and a fungus. The SAR study revealed that complex 1 exhibited the best antimicrobial effects and higher antioxidant activity than complex 2 and L.
- Benhassine, Anfel,Boulebd, Houssem,Anak, Barkahem,Ali, Mounira Kara,Bouraiou, Abdelmalek,Merazig, Hocine,Kacem-Chaouche, Noureddine,Belfaitah, Ali
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- Catalytic phosphorylation using a bifunctional imidazole derived nucleophilic catalyst
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A bifunctional catalyst containing a polyether backbone and a nucleophilic imidazole moiety has been prepared that demonstrates cooperative catalysis in the presence of added group 1 and 2 salts for the phosphorylation of alcohols. The Royal Society of Chemistry 2005.
- Jones, Simon,Northen, Julian,Rolfe, Alan
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Read Online
- Charge-Compensated Metallacarborane Building Blocks for Conjugation with Peptides
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The cobalt bis(dicarbollide) complex [commo-3,3′-Co(1,2-C2B9H11)2]- has captured much attention in biochemical and medical contexts, in particular for the treatment of tumors by boron neutron capture therapy (BNCT). Derivatives of cobalt bis(dicarbollide) are commonly prepared through ring-opening reactions of cyclic oxonium ions, so the corresponding products are usually charged. Furthermore, attempts to incorporate cobalt bis(dicarbollide) into peptides are rare, despite obvious potential advantages. Here the synthesis of an imidazolium-based charge-compensated cobalt bis(dicarbollide) building block, which allows additional modifications with moieties of biochemical relevance, such as monosaccharides, is reported. Furthermore, conjugates of these building blocks with the Y1-receptor-selective derivative of neuropeptide Y ([F7,P34]-NPY) retained excellent response to hY1 receptors found to be overexpressed in breast tumors and metastases.
- Frank, René,Ahrens, Verena M.,Boehnke, Solveig,Beck-Sickinger, Annette G.,Hey-Hawkins, Evamarie
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- Synthesis, crystal structure, and SOD-like activity of two copper(II) complexes with hydroxymethyl pendants
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Dinuclear and mononuclear copper(II) complexes (1, [Cu2(HL)2(L)2](ClO4)2; 2, [Cu(HL)2(phen)] (ClO4)2, where HL = (N-methyl-2-methylol)imidazole, phen = 1,10-phenanthroline) have been synthesized and characterized by single crystal X-ray diffraction. The SOD-like activity (IC50) of 1 and 2 were measured to be 0.10 ± 0.01 and 0.19 ± 0.01 μM by NBT assay at pH 7.8. The higher SOD activity of 1 could be contributed to the coordination configuration and the labile hydroxymethyl pendants. Electrochemistry and the frontier molecular orbital energies of the complexes were also studied. To mimic the active site of Cu, Zn-SOD, new copper(II) complexes (1, [Cu2(HL)2(L)2](ClO4)2; 2, [Cu(HL)2(phen)](ClO4)2; where HL = (N-methyl-2-methylol)imidazole, phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Copper(II) in 1 is four-coordinate by a N2O2 plane with two copper(II) ions bridged with two oxygens from the deprotonated hydroxylmethyl pendants. Each Cu2+ in 2 is coordinated by four nitrogens from two HL and one co-ligand of 1,10-phenanthroline. Electrochemistry of the complexes was studied by cyclic voltammetry. The atomic net charges distribution and frontier molecular orbital energies were obtained by Gaussian 98 program with DFT method at B3LYP/lanl2dz level. The SOD-like activity (IC50) of 1 and 2 were measured as 0.10 ± 0.01 and 0.19 ± 0.01 μM by NBT assay at pH 7.8. The higher SOD activity of 1 could be attributed to the coordination configuration and the labile hydroxymethyl pendants.
- Zhou, Ying-Hua,Sun, Da-Liang,Tao, Jun,Chen, Li-Qing,Huang, Ya-Fan,Li, Ying-Kun,Cheng, Yong
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- Efficient fixation of CO2 into organic carbonates catalyzed by 2-hydroxymethyl-functionalized ionic liquids
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Several novel 2-hydroxymethyl-functionalized ILs act as the catalysts for synthesis of cyclic carbonates from CO2 and epoxides without the use of any co-catalysts or organic solvent. Moreover, the 2-hydroxymethyl- functionalized ILs were compatible with base, which combined with K 2CO3 were used as effective catalytic system for green synthesis of dimethyl carbonate from CO2via ethylene carbonate without catalyst separation. Additionally, the mechanistic details of the fixation of CO2 into cyclic carbonate catalyzed by 2-hydroxymethyl-functionalized ILs were also elucidated by density functional theory. The process reported here represents a simple, ecologically safer, cost-effective and energy-saving route to organic carbonates from CO 2.
- Wang, Jin-Quan,Cheng, Wei-Guo,Sun, Jian,Shi, Tian-Yuan,Zhang, Xiang-Ping,Zhang, Suo-Jiang
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- New Cd(II) complex derived from (1-methylimidazol-2-yl) methanol: Synthesis, crystal structure, spectroscopic study, DFT and TD-DFT calculations, antimicrobial activity and free-radical scavenging capacity
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A combined experimental and theoretical study of new complex with a formula of [Cd(Hmim)2(OAc)2], where Hmim stands for (1-methyl-1H-imidazol-2-yl) methanol has been reported. The complex was characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR and UV-vis spectroscopy. The crystal structure of the complex shows that two Hmim and two carboxylate groups are coordinated to the Cd(II) ion in monodentate fashion through the nitrogen and carboxylic oxygen atoms displaying a distorted tetrahedral geometry. Detailed theoretical studies were performed using DFT and TD-DFT calculations, other properties such as chemical bonding analysis (QTAIM, RDG, DOS) have been also carried out and are in agreement with the experimental results. The ligand and its Cd(II) complex have been screened in vitro and evaluated for their potential as DPPH radical scavengers as well as antimicrobial agents against five pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, a yeast and a fungus using the agar diffusion method. The SAR study showed that the free ligand exerts no inhibitory activity, except a moderate activity against the yeast, while the complex exhibits an antimicrobial activity more potent or similar to that of standard drugs against all selected microorganisms, and a moderate to interesting antioxidant potential compared to Vitamin C as control.
- Belfaitah, Ali,Bencharif, Mustapha,Benhassine, Anfel,Chouiter, Mohamed Imed,Kacem-Chaouche, Noureddine,Kara Ali, Mounira,Merazig, Hocine
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- PNO ligand containing planar chiral ferrocene and application thereof
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The invention discloses a PNO ligand containing planar chiral ferrocene and application thereof. The PNO ligand containing planar chiral ferrocene is a planar chiral ferrocene-containing and phenol-containing PNO ligand as shown in a general formula (I) or (II) which is described in the specification, or a planar chiral ferrocene-containing and aryl-phosphoric-acid-containingPNO ligand containing as shown in a general formula (III) or (IV) which is described in the specification, or a planar chiral ferrocene-containing and carbon-chiral-phenol-containingPNO ligand as shown in a general formula (V) or (VI) which is described in the specification. The invention provides tridentate PNO ligands and processes for their complexation with transition metal salts or transition metal complexes; the introduction of salicylaldehyde and derivatives thereof, which are simple and easy to obtain, enables the ligands to have a bifunctionalization effect, and -OH in a formed catalyst has stronger acidity and is beneficial to combination with N/O in polar double bonds. Therefore, due to the bifunctionalization effect of the catalyst, the interaction between the catalyst and a substrate can be greatly improved, so a reaction can obtain higher catalytic activity and stereoselectivity.
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Paragraph 0114-0118
(2021/06/21)
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- Ionic liquid which has a low cellulose decomposition efficiency
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The present invention refers to cellulose decomposition rate of low relates to ionic liquid, the present invention according to ionic liquids compatible ionic liquid and similar or its solubility with cellulose compared to as well as superior, has a remarkably decomposition rate of cellulose disintegration when they dissolve in an unique cellulose therefore, the problem that the components close to by the polyester copolymer. useful. (by machine translation)
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Paragraph 0175; 0178; 0179; 0180
(2017/04/13)
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- Synthesis, crystal structure and antibacterial activity of new highly functionalized ionic compounds based on the imidazole nucleus
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Several new highly functionalized imidazolium derivatives were synthesized, via appropriate synthetic routes, using imidazole, 1-methylimidazole and 2-phenyl-1-methylimidazole as key intermediates. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella thipymurium using disk-diffusion and MIC methods. Crystal X-ray structures are reported for six compounds.
- Bahnous, Mebarek,Bouraiou, Abdelmalek,Chelghoum, Meryem,Bouacida, Sofiane,Roisnel, Thierry,Smati, Farida,Bentchouala, Chafia,Gros, Philippe C.,Belfaitah, Ali
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p. 1274 - 1278
(2013/03/14)
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- Pyruvamide Compounds as Inhibitors of Dust Mite Group 1 Peptidase Allergen and Their Use
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The present invention pertains generally to the field of therapeutic compounds and more specifically to certain pyruvamide compounds of the formula (X) (for convenience, collectively referred to herein as “PVA compounds”), which, inter alia, inhibit a dust mite Group 1 peptidase allergen (e.g., Der p 1, Der f 1, Eur m 1). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit a dust mite Group 1 peptidase allergen, and in the treatment of diseases and disorders that are mediated by a dust mite Group 1 peptidase allergen; that are ameliorated by the inhibition of a dust mite Group 1 peptidase allergen; asthma; rhinitis; allergic conjunctivitis; atopic dermatitis; an allergic condition which is triggered by dust mites; an allergic condition which is triggered by a dust mite Group 1 peptidase allergen; and canine atopy.
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- Syntheses, protonation constants and antimicrobial activity of 2-substituted N-alkylimidazole derivatives
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A series of N-alkylimidazole-2-carboxylic acid, N-alkylimidazole-2- carboxaldehyde and N-alkylimidazole-2-methanol derivatives [alkyl = benzyl, methyl, ethyl, propyl, butyl, heptyl, octyl and decyl] have been synthesized and the protonation constants determined. The antimicrobial properties of the compounds were tested against Gram-negative (Escherichi coli), Gram-positive (Staphylococcus aureus & Bacillus subtilis subsp. spizizenii) bacterial strains and yeast (C. albicans). Both the disk diffusion and broth microdilution methods for testing the antimicrobial activity showed that N-alkylation of imidazole with longer alkyl chains and the substitution with low pKa group at 2-position resulted in enhanced antimicrobial activity. Particularly, the N-alkylimidazole-2-carboxylic acids exhibited the best antimicrobial activity due to the low pKa of the carboxylic acid moiety. Generally, all the N-alkylimidazole derivatives were most active against the Gram-positive bacteria [S. aureus (MIC = 5-160 μg mL-1) and B. subtilis subsp. spizizenii (5-20 μg mL-1)], with the latter more susceptible. All the compounds showed poor antimicrobial activity against both Gram-negative (E. coli, MIC = 0.15 to >2500 μg mL-1) bacteria and all the compounds were inactive against the yeast (Candida albicans).
- Kleyi, Phumelele,Walmsley, Ryan S.,Gundhla, Isaac Z.,Walmsley, Tara A.,Jauka, Tembisa I.,Dames, Joanna,Walker, Roderick B.,Torto, Nelson,Tshentu, Zenixole R.
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p. 231 - 238
(2013/01/15)
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- Investigation of carbon-2 substituted imidazoles and their corresponding ionic liquids
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The functionality at the C-2 position of the imidazole ring plays a key role in defining the chemical properties of the imidazoles and their corresponding ionic liquids. Imidazoles 1-6 with different C-2 functionality were synthesized and their corresponding ionic liquids were systematically investigated. Based on their physical properties the six imidazoles can be divided into three groups. (1) The imidazoles 2 and 3 are capable of self-polymerization to form poly(ionic liquid)s, and they are characterized with a strong leaving group at the C-2 position. (2) The imidazoles 4 and 5 can form ionic liquids, but they are very sensitive to moisture. (3) The imidazoles 1 and 6 can form stable ionic liquids, and their stabilities were influenced by the electronic effects of the substituents at the C-2 position.
- Liao, Chen,Zhu, Xiang,Sun, Xiao-Guang,Dai, Sheng
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supporting information; experimental part
p. 5308 - 5310
(2011/10/30)
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- Physicochemical properties of imidazolium-derived ionic liquids with different C-2 substitutions
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Five room temperature ionic liquids based on C-2 substituted imidazolium cations and bis(trifluoromethanesulfonyl)imide (TFSI) anions were synthesized and their physicochemical properties: thermal property, density, viscosity, ionic conductivity, self-diffusion coefficients, and electrochemical stability, were systematically investigated. The temperature dependence of both viscosity and ionic conductivities of these ionic liquids can be described by the Vogel-Fulcher-Tamman (VFT) equation. Compared with the reference, 1-propyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, the introduction of functional groups at the C-2 position generally increased the viscosity and lowered the ionic conductivity. The introduction of an ether group (-CH2OCH2CH2CH2CH3) at the C-2 position not only enhanced the reduction stability of the ionic liquids but also exhibited the lowest solid electrolyte interfacial resistance (R SEI). In contrast, the introduction of a cyano group (-CN) at the C-2 position not only decreased the reduction stability but also adversely increased the SEI resistance. The effect of the C-2 substitution on the reduction stability was explained by the change in the energy level of the lowest unoccupied molecular orbital. The self-diffusion coefficients (D) of each ion were measured by pulsed field gradient nuclear magnetic resonance (PFG-NMR). The lithium transference number (tLi) of 0.5 M LiTFSI/IL solutions calculated from the self-diffusion coefficients was in the range of 0.04 to 0.09.
- Liao, Chen,Shao, Nan,Han, Kee Sung,Sun, Xiao-Guang,Jiang, De-En,Hagaman, Edward W.,Dai, Sheng
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experimental part
p. 21503 - 21510
(2012/03/10)
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- Asymmetric reduction of ketimines with trichlorosilane employing an imidazole derived organocatalyst
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Organocatalysts for the asymmetric reduction of ketimines are presented that function well at low catalyst loadings providing chiral amines in good yield and enantioselectivity, the latter appearing to be independent of the ketimine substrate geometry.
- Gautier, Franois-Moana,Jones, Simon,Martin, Stephen J.
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supporting information; experimental part
p. 229 - 231
(2009/03/11)
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- Amino-Containing Compounds Which Inhibit Memapsin 2 Beta-Secretase Activity and Methods of Use Thereof
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The present invention provides novel beta-secretase inhibitors and methods for their use, including methods of treating of Alzheimer's disease.
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Page/Page column 19-20
(2008/12/05)
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- IMIDAZOLE DERIVATIVES AND THEIR USE FOR MODULATING THE GABA-A RECEPTOR COMPLEX
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This invention relates to novel imidazole derivatives of formula (I), pharmaceutical compositions containing these compounds, and methods of treatment therewith. The compounds of the invention are useful in the treatment of central nervous system diseases and disorders, which are responsive to modulation of the GABAA receptor complex, and in particular for combating anxiety and related diseases.
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Page/Page column 18
(2008/06/13)
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- SULPHONAMIDE DERIVATIVES, THEIR PREPARATION AND THEIR THERAPEUTIC APPLICATION
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Disclosed are compounds having the general formula (I) as defined herein, the preparation thereof, and the use thereof for the prophylaxis or treatment of any disease involving a dysfunction associated with the orexin 2 receptor such as obesity, appetite or taste disorders including cachexia, anorexia and bulimia, diabetes, metabolic syndromes, vomiting and nausea, depression and anxiety, addictions, mood and behaviour disorders, schizophrenia, sleep disorders, restless legs syndrome, memory learning disorders, sexual and psychosexual dysfunctions, pain, visceral or neuropathic pain, hyperalgesia, allodynia, digestive disorders, irritable bowel syndrome, neuronal degenerescence, ischaemic or haemorrhagic attacks, Cushing's disease, Guillain-Barré syndrome, myotonic dystrophy, urinary incontinence, hyperthyroidism, pituitary function disorders, hypertension or hypotension.
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Page/Page column 67
(2010/11/28)
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- ISOXAZOLINE DERIVATIVES AND THEIR USE AS HERBICIDES
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Compounds of formula (I) wherein the substituents are as defined in claim 1, are suitable for use as herbicides. Also claimed is a process for the preparation of compounds of the formula I, wherein m is 2 and n is 1, and the other substituents are defined as in claim 1, formula (Ia) by reacting a compound of the formula Ia in a single step or stepwise in succession with compounds of the formula R5-X and/or R6-X, wherein R5 and R6 are as defined in claim 1, and X is a leaving group, and a process for the preparation of compounds of the formula I, wherein R6 is C1--C10alkyl or halogen, m is 2 and n is 1, and the other substituents are defined as in claim 1, formula (Ib) by reacting a compound of the formula 1b with a compound of the formula R5-X, wherein R5 is as defined in claim 1, and X is a leaving group, and a process for the preparation of compounds of the formula I, wherein R5 is chlorine, bromine or iodine, m is 1 or 2, and n is 1, and the other substituents are defined as in claim 1, formula (Ic) by reacting a compound of the formula le with an N- halosuccinimide and an oxidising agent.
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Page/Page column 127
(2010/10/20)
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- BICYCLIC COMPOUNDS WHICH INHIBIT BETA-SECRETASE ACTIVITY AND METHODS OF USE THEREOF
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The present invention provides bicyclic beta-secretase inhibitors and methods for their use, including methods of treating of Alzheimer’s disease.
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Page/Page column 60
(2010/10/20)
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- BASIC AMINE COMPOUND AND USE THEREOF
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Novel amine compounds which are represented by the following formula (1) and efficacious against diseases such as a viral infectious disease with HIV, rheumatism, and cancer metastasis; typically, A 1 and A 2 represent a hydrogen atom or a substitutable monocyclic or polycyclic heteroaromatic ring and W represents a substitutable benzene ring or any group represented by the following formula (10) or (11): where X represents O, CH 2 , C(=O), NR 11 , or CHR 35 and D represents a group represented by the following formula (6): where Q represents a single bond, NR 12 , or a group represented by the formula (13): and Y represents a group represented by the following formula (7) : where z represents a substitutable monocyclic or polycyclic aromatic ring; and B represents -NR 25 R 26 ; and R 1 to R 26 in the above formulae represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.
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Page/Page column 29
(2010/11/24)
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- Orally active CCR5 antagonists as anti-HIV-1 agents. Part 3: Synthesis and biological activities of 1-benzazepine derivatives containing a sulfoxide moiety
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In order to develop orally active CCR5 antagonists, 1-propyl- or 1-isobutyl-1-benzazepine derivatives containing a sulfoxide moiety have been designed, synthesized, and evaluated for their biological activities. Sulfoxide compounds containing a 2-pyridyl
- Seto, Masaki,Miyamoto, Naoki,Aikawa, Katsuji,Aramaki, Yoshio,Kanzaki, Naoyuki,Iizawa, Yuji,Baba, Masanori,Shiraishi, Mitsuru
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p. 363 - 386
(2007/10/03)
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- BENZAZEPINE DERIVATIVE, PROCESS FOR PRODUCING THE SAME, AND USE
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The present invention provides a novel benzazepine derivative represented by formula : wherein, R1 is a 5- or 6-membered aromatic ring, R2 is lower alkyl group, etc., Y is an optionally substituted imino group, ring A and ring B are independently an optionally substituted aromatic ring, W is formula -W1-X2-W2- (W1 and W2 are independently S(O)m1 (m1 is 0, 1 or 2), etc., and X2 is an optionally substituted alkylene groupetc. ), a preparation method and use thereof.
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- Ligand and complex for catalytically bleaching a substrate
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The invention relates to ligands or complexes useful as catalysts for catalytically bleaching substrates with atmospheric oxygen, and as catalysts in the of treatment of textiles such as laundry fabrics whereby bleaching by atmospheric oxygen is catalysed after the treatment. The ligand is of the general formula: wherein R1, R2, and R3independently represent a group selected from methyl, pyridin-2-yl, quinolin-2-yl, pyrazol-1-yl, 3,5-dimethylpyrazol-1-yl, N-methyl-amido, and N-isopropyl-amido; provided at least two of R1, R2and, R3represent a coordinating group, the ligand being selected from: 1,4-bis(pyridin-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(quinolin-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(pyrazol-1-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(3,5-dimethylpyrazol-1-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4-bis(N-methylimidazol-2-ylmethyl)-7-ethyl-1,4,7-triazacyclononane; 1,4,7-tris(quinolin-2-ylmethyl)-1,4,7-triazacyclononane; 1,4-bis(N-isopropylacetamido)-7-ethyl-1,4,7-triazacyclononane; and 1,4-bis(N-methylacetamido)-7-ethyl-1,4,7-triazacyclononane.
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Page/Page column 9-10
(2010/01/31)
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- Design, synthesis and evaluation of imidazolylmethyl carbamate prodrugs of alkylating agents
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Two approaches to prodrugs of alkylating agents based on an imidazolylmethyl carbamate nucleus were explored. A 2-azido analogue (3) of the bis-carbamate carmethizole (1) displayed similar aerobic cytotoxicity to 1 in a panel of human and murine cell lines. Approaches to the 2-amino and 2- carbamoyl analogues are described. In the second approach an imidazolylmethanol was used as a 'trigger' linked via a carbamate to the alkylating agent N,N-bis(2-chlorethyl)amine (BCEA). Nitroimidazole and methylsulphinylimidazole carbamate prodrugs 6-8 were 5-20-fold less toxic than BCEA. Despite this deactivation in the prodrug form, little increase in cytotoxicity was observed under hypoxia. The data suggest that BCEA released on bioreduction is not sufficiently potent to contribute significant additional cytotoxicity. (C) 2000 Elsevier Science Ltd.
- Hay, Michael P.,Wilson, William R.,Denny, William A.
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p. 645 - 657
(2007/10/03)
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- Synthesis of ω-carbamoyloxyalkylimidazolium salts for evaluation as protective agents against acetylcholinesterase intoxication by soman
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A series of N-methyl and N,N-dimethylcarbamoyloxyalkylimidazolium salts has been prepared. The carbamoyloxyalkyl groups are varied from methyl through propyl at the 1,2 or 4 positions of the imidazolium ring. The 2- and 4-substituted series show modest activity as inhibitors of acetylcholinesterase. Several of the compounds show prophylactic activity against soman toxicity but there is no correlation between AChE inhibitory activity and the prophylatic effect, suggesting that reversible carbamoylation is not the basis for the prophylactic effect.
- Sundberg, Richard J.,Van Nguyen, Phuoc
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p. 123 - 136
(2007/10/03)
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- A direct synthetic approach to novel quadrupolar [14]azolophanes
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A convergent '3+1' synthesis allowed a simple entrance to the first examples of [14]metaazolophanes 1 and [14l(meta-ortho)2azolophanes 2 built up from heterocyclic betaine subunits, illustrating a prototype of phanes constructed by both highly π-excessiveand highly π-deficient heteroaromatic moieties linked in a 1,3-alternating fashion.
- Alcalde, Ermitas,Alemany, Montserrat,Gisbert, Maria
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p. 15171 - 15188
(2007/10/03)
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- Phosphotriesters Approach to the Synthesis of Oligonucleotides: A Reappraisal
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The phosphotriester approach to the synthesis of oligodeoxyribo- and oligoribo-nucleotides in solution has been reinvestigated.The efficacy of mesitylene-2-sulfonyl chloride (MSCl) 15a, 2,4,6-triisopropylbenzenesulfonyl chloride (TrisCl) 15b, 4-bromobenzenesulfonyl chloride 15c, naphthalene-1-sulfonyl chloride 39, and 2- and 4-nitrobenzenesulfonyl chlorides 40a and 40b, respectively, as activating agents has been examined.The latter arenesulfonyl chlorides have been used in conjunction with the following nucleophilic catalysts: 1-methylimidazole, 3-nitro-1H-1,2,4-triazole 19, 5-(3-nitrophenyl)-1H-tetrazole 20a, 5-(3,5-dinitrophenyl)-1H-tetrazole 20b, 5-(1-methylimidazol-2-yl)-1H-tetrazole 21, 5--1H-tetrazole 22, 4-ethoxypyridine 1-oxide 14a, 4,6-dinitro-1-hydroxybenzotriazole 29a, 1-hydroxy-4-nitro-6-(trifluoromethyl)benzotriazole 29b, 1-hydroxy-5-phenyltetrazole 30a and 1-hydroxy-5-(3-nitrophenyl)tetrazole 30b.The rates of formation and yields of the fully protected dideoxyribonucleoside and diribonucleoside phosphates 37 and 47, respectively, were determined using various combinations of activating agents and nucleophilic catalysts.Although 2- and 4-nitrobenzenesulfonyl chlorides 40a and 40b, respectively, proved to be the most powerful activating agents, their use in the deoxy-series led to the formation of by-products and hence to unsatisfactory isolated yields of the dideoxyribonucleoside phosphate 37.
- Reese, Colin B.,Pei-Zhuo, Zhang
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p. 2291 - 2302
(2007/10/02)
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- 6-(SUBSTITUTED)METHYLENE-PENICILLANIC AND 6-(SUBSTITUTED)HYDROXYMETHYL-PENICILLANIC ACIDS AND DERIVATIVES THEREOF
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Beta-lactamase inhibiting compounds of the formula: or a pharmaceutically acceptable acid addition or carboxylate salt thereof; where n is zero, 1 or 2; X.3 is H or Br, R1 is H, the residue of certain carboxy-protecting groups or the residue of an ester group readily hydrolyzable in vivo; one of R12 and R13 is H and the other is vinyl, certain aryl, alkylthio, alkylsulfonyl or certain heterocyclyl, aminomethyl, thiocarboxamido or amidino groups; one or R2 and R3 is H and the other is as disclosed for the other of R12 and R13, or is Cl or CH2 OH, and R18 is H or certain acyl groups; intermediates useful in their production, methods for their preparation and use, and pharmaceutical compositions containing them
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- Azide ion trapping and lifetime in aqueous solution of a primary carbenium ion stabilized by a 2-imidazoyl ring
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2-Chloromethyl-1-methylimidazole undergoes a pH-dependent aqueous hydrolysis with the neutral substrate being the reactive species, and the imidazole-protonated form (pKa=5.7) unreactive.Addition of sodium chloride retards the hydrolysis, evidence that there is a free carbenium ion intermediate (the common ion effect).The rate constant ratio kCl/kw for the reactions of this cation with the added chloride and with the solvent is 7.4 M-1.Further evidence for a free cation is the observation of the 2-azidomethyl product when the hydrolysis is carried out with sodium azide present, but with no change in the rate constant.The kaz/kw ratio as determined by product analysis is 1.1*102 M-1.With the assumption that kaz represents a diffusion-controlled reaction and has a value of 7*109 M-1s-1, the rate constant kw for the reaction of the cation with solvent is 6*107 s-1.A comparison with azide-water selectivity ratios reported for other cations shows that the imidazole-stabilized primary cation of this study is relatively long-lived.A possible explanation for this is given, in terms of the extensive resonance delocalization of the positive charge in this cation.Keywords: solvolysis, carbenium ion, heterocycle.
- Bolton, Judy L.,McClelland, Robert A.
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p. 1139 - 1143
(2007/10/02)
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- Substituted thiazoles as immunoregulants
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Thiazole derivatives have been made, for example, by reacting a 2-aryl-2,2-dialkoxyethylamine with an appropriately substituted aryl acetyl halide followed by treating the resulting amide with diphosphoryl pentasulfide. The thiazole derivatives are found to be effective immunoregulants.
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- Isocimetidine and analogues. XXIII. H2-antihistaminics
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Isocimetidine (7), an isomer of cimetidine, as well as the analogous 4-pyrimidones 9a,b were prepared and tested for their H2- and H1-antagonistic activity. 9a,b possess similar pA2-values on the guinea pig atrium, but sma
- Buschauer,Schunack
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p. 1223 - 1224
(2007/10/02)
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