- Synthesis, Characterization, and Viscosification of Amidosulfobutaine and Zwitterionic Gemini Surfactants
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The viscoelastic surfactants (VES)-based acid diverters are frequently used to divert acid flow from high-permeability layers into low-permeability for enhanced overall productivity of the treated well. In general, an optimum VES-based system possesses advantages of decrease in absorption loss, damage of reservoir, and improved adaptability of active agents to high salinity. Herein, we report the synthesis of three new zwitterionic gemini surfactants (1–3) and previously known amidosulfobutaine (C18AMP3SB) has been accomplished for the investigation of diverting acid performance. The synthesis of these surfactants was achieved by the amidation of the acid chlorides of commercially available fatty acids with 3-(dimethylamino)-1-propylamine followed by subsequent reactions with appropriate sultone or ethyl 4-bromobutanoate. The synthesized surfactants were well characterized by spectroscopic methods including IR and NMR spectroscopy. The thermogravimetric analysis (TGA) results suggested that surfactants (1–3) and C18AMP3SB possess excellent thermal stability, with no appreciable loss of mass up to 300°C. The viscosity measurements of the neat surfactants (1–3) and C18AMP3SB were performed under various temperatures, in the presence of different concentration of calcium chloride salt with the aid shear viscosimetry. The analysis revealed that the viscosity of neat C18AMP3SB increases with increase in concentration of CaCl2. With 10% CaCl2 solution, the viscosity was increased from 7.5 to 33.55 cPs, whereas in 20% CaCl2 the viscosity reached to 102 cPs with rise in temperature from ambient to 90°C. Moreover, the viscosity of neat surfactants (1–3) did not exhibit any appreciable viscosity change under the experimental conditions. However, the mixture of surfactants (1–3) each in combination with C18AMP3SB (1:1) displayed significant upsurge in the viscosity, up to more than 10 folds.
- Mansha, Muhammad,Ullah, Nisar,Kalgaonkar, Rajendra A.,Baqader, Nour
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Read Online
- Electrochemical and nonelectrochemical analyses of cardo polyesters at the metal/0.5?M H2SO4 interface for corrosion protection
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With the aim of decreasing the corrosion of metal specimens, two polyesters, namely 4-(1-(4-methoxyphenyl)cyclohexyl)phenyl 3-oxobutanoate (MPOB) and 4-(1-(4-methoxyphenyl)cyclohexyl)phenyl 10-oxoundecanoate (MPOU), were synthesized and utilized as corrosion inhibitors. The synthesized polyesters were characterized by Fourier-transform infrared (FT-IR) and nuclear magnetic resonance spectral analyses, followed by thermogravimetric and differential scanning calorimetry analyses. The protective effect of the polyesters on mild-steel specimens in 0.5?M H2SO4 medium was evaluated by nonelectrochemical and electrochemical methods. Gravimetric measurements revealed a decreased corrosion rate with increasing concentration of the inhibitors, reaching a maximum inhibition efficiency of 79.88% for MPOB and 92.98% for MPOU at 1000?ppm concentration at room temperature. The obtained experimental data were best fit by the Langmuir adsorption isotherm, suggesting monolayer adsorption. Thermodynamic parameters supported a physisorption mechanism. Electrochemical impedance spectroscopy showed increased charge-transfer resistance (Rct), in turn decreasing the double-layer capacitance and thereby favoring good inhibition of corrosion of mild steel. Mixed-type inhibition was revealed by potentiodynamic polarization analysis, suppressing anodic metal dissolution and cathodic hydrogen evolution. The mode of adsorption of the inhibitors on the mild-steel surface was additionally evaluated by morphological study using FT-IR and atomic force microscopy (AFM) analyses.
- Unnisa, Chan Basha Nusrath,Chitra, Subramanian,Nirmala Devi, Gowraraju,Kiruthika, Ayyasamy,Roopan, Selvaraj Mohana,Hemapriya, Venkatesan,Chung, Ill-Min,Kim, Seung-Hyun,Prabakaran, Mayakrishnan
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Read Online
- Synthesis and characterization of cyclic alkyl tetraynes
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Cyclic (4a-e) and linear (10) tetraynes have been studied. Macrocycles 4a-e are unstable to isolation as neat compounds, but 4b-e have been characterized in solution. 13C NMR spectroscopy shows a consistent downfield shift of the acetylenic resonances of 4c-e as ring strain increases. UV-vis spectroscopy demonstrates that ring strain has little effect on the HOMO-LUMO gap. X-ray crystallography of tetrabromoolefin 6b confirms the monomeric constitution of the precursors.
- Spantulescu, Andreea,Luu, Thanh,Yuming, Zhao,McDonald, Robert,Tykwinski, Rik R.
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- Synthesis and bio-evaluation of Tc-99 m-labeled fatty acid derivatives for myocardial metabolism imaging
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11C, 18F and 123I fatty acids are used for myocardial imaging, and 99mTc-labeled fatty acids are more desirable substitutes than other radiolabeled fatty acids. In the work reported, [99mTc]-CpTT-10-oxo-FPA (1c), [99mTc]-CpTT-12-oxo-FPA (2c), [99mTc]-CpTT-14-oxo-FPA (3c) and [99mTc]-CpTT-16-oxo-FPA (4c) were prepared with 60.76–70.92% of radiochemical yield and purity of more than 95%. These radiotracers (1c, 2c, 3c, 4c) were chemically stable when incubated in Sprague Dawley rat serum for 3 h at 37 °C. Tissue distribution studies in female mice indicated that 2c had high initial heart uptake (8.84%ID g?1 at 1 min post-injection) and 4c had long retention in the heart (1.45%ID g?1 at 30 min post-injection). Metabolite analysis showed 4c could be metabolized to 5c via β-oxidation with loss of two ?CH2? in the myocardium, the radiometabolite being excreted via urine. However, low heart uptake suggested that 4c cannot be used as a diagnostic imaging agent. Copyright
- Liu, Jianping,Xue, Qianqian,Wang, Huan,Wang, Hang,Wang, Dawei,Fang, Yu,Zhang, Huabei
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Read Online
- Synthesis of α,ω-Diketodiesters from Betulin
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A new synthesis of 3-oxo-28-hydroxylup-20(29)-ene from the available natural triterpenoid betulin was developed. α,ω-Diketodiesters were prepared for the first time by different methods from 3-oxo-28-hydroxylup-20(29)-ene and a series of natural dicarboxylic acids. Steglich reaction conditions gave the highest yields. One of the synthesized α,ω-diketodiesters was moderately active in vitro against A-549 lung carcinoma.
- Ishmuratov, G. Yu.,Sayakhov, R. R.,Talipov, R. F.,Vydrina, V. A.,Yakovleva, M. P.,Zileeva, Z. R.
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p. 706 - 711
(2021/07/31)
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- LIPID PRODRUGS OF GLUCOCORTICOIDS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00404; 00405
(2020/09/12)
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- LIPID PRODRUGS OF PREGNANE NEUROSTEROIDS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, as well as methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00293
(2020/02/23)
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- LIPID PRODRUGS OF JAK INHIBITORS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00411-00412
(2020/09/12)
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- LIPID PRODRUGS OF BTK INHIBITORS AND USES THEREOF
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, and methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a disclosed lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00405; 00420; 00421
(2020/09/12)
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- LYMPHATIC SYSTEM-DIRECTING LIPID PRODRUGS
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The present invention provides lymphatic system-directing lipid prodrugs, pharmaceutical compositions thereof, methods of producing such prodrugs and compositions, as well as methods of improving the bioavailability or other properties of a therapeutic agent that comprises part of the lipid prodrug. The present invention also provides methods of treating a disease, disorder, or condition such as those disclosed herein, comprising administering to a patient in need thereof a provided lipid prodrug or a pharmaceutical composition thereof.
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Paragraph 00427; 00428
(2019/03/17)
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- Synthesis of bis-4H-furo[3,4-b]indoles
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We describe the synthesis of two novel bis-4H-furo[3,4-b]indoles from indole. Several alternative pathways to these potential DNA bis-intercalator precursors are discussed, and the synthesis of a novel semi-rigid tether is reported.
- McGowan, Meredeth A.,Perreault, Denise M.,Thornton, Nancy B.,Garaas, Sarah D.,Gribble, Gordon W.
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p. 334 - 347
(2018/09/10)
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- Symmetric dimeric adamantanes for exploring the structure of two viroporins: Influenza virus M2 and hepatitis C virus p7
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Background: Adamantane-based compounds have been identified to interfere with the ion-channel activity of viroporins and thereby inhibit viral infection. To better understand the difference in the inhibition mechanism of viroporins, we synthesized symmetric dimeric adamantane analogs of various alkyl-spacer lengths. Methods: Symmetric dimeric adamantane derivatives were synthesized where two amantadine or rimantadine molecules were linked by various alkyl-spacers. The inhibitory activity of the compounds was studied on two viroporins: the influenza virus M2 protein, expressed in Xenopus oocytes, using the two-electrode voltage-clamp technique, and the hepatitis C virus (HCV) p7 channels for five different genotypes (1a, 1b, 2a, 3a, and 4a) expressed in HEK293 cells using whole-cell patch-clamp recording techniques. Results: Upon testing on M2 protein, dimeric compounds showed significantly lower inhibitory activity relative to the monomeric amantadine. The lack of channel blockage of the dimeric amantadine and rimantadine analogs against M2 wild type and M2-S31N mutant was consistent with previously proposed drug-binding mechanisms and further confirmed that the pore-binding model is the pharmacologically relevant drug-binding model. On the other hand, these dimers showed similar potency to their respective monomeric analogs when tested on p7 protein in HCV genotypes 1a, 1b, and 4a while being 700-fold and 150-fold more potent than amantadine in genotypes 2a and 3a, respectively. An amino group appears to be important for inhibiting the ion-channel activity of p7 protein in genotype 2a, while its importance was minimal in all other genotypes. Conclusion: Symmetric dimeric adamantanes can be considered a prospective class of p7 inhibitors that are able to address the differences in adamantane sensitivity among the various genotypes of HCV.
- Mandour, Yasmine M.,Breitinger, Ulrike,Ma, Chunlong,Wang, Jun,Boeckler, Frank M.,Breitinger, Hans-Georg,Zlotos, Darius P.
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p. 1019 - 1031
(2018/05/22)
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- Isoniazid Conjugates with D-Arabinofuranose
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Glycoconjugates with isoniazid attached to the hydroxy group at the С5 atom of D-arabinofuranose via the spacers differing in length have been synthesized.
- Andreeva,Kataev
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p. 1411 - 1417
(2018/09/10)
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- Thermotropic liquid crystalline polyesters derived from 2-chloro hydroquinone
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Abstract: Synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology is presented. Synthesised polyesters consist of bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene as a mesogen and aliphatic diacid chloride as flexible spacer. The length of oligomethylene units in the polymer was varied from the trimethylene to the dodecamethylene groups. Synthesized polyesters were characterized by differential scanning calorimetry and optical microscopy. The transition temperatures and thermodynamic properties were studied for all these polymers. These polyesters exhibited thermotropic liquid crystalline behavior and showed nematic texture except decamethylene spacer. Decamethylene spacer based polyester showed marble texture of smectic C. Mesophase stability of these polyesters was higher than 123 °C (except first heating cycle of PE-1). Graphical Abstract:: SYNOPSIS The present study deals with the synthesis of thermotropic liquid crystalline polyesters derived from bis[4-hydroxy benzoyloxy]-2-chloro-1,4-benzene (BHBOCB) and aliphatic dicarboxylic acid chlorides by interfacial polycondensation methodology. [Figure not available: see fulltext.].
- Manurkar, Nagesh,More, Sayaji,Mulani, Khudbudin,Ganjave, Nitin,Chavan, Nayaku
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p. 1461 - 1468
(2017/09/27)
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- Preparation method of acyl chloride
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The invention relates to a preparation method of acyl chloride. The method comprises the following steps that 1, carboxylic acid is added into a reactor, or carboxylic acid is dissolved in organic solvent, a device is connected, and the temperature is raised to 100 DGE C-250 DEG C; 2, phosgene is introduced into the reactor for a reaction, and then the temperature is decreased to room temperature; 3, nitrogen is introduced, residual phosgene and hydrogen chloride are cleaned away, reaction liquid which is reacted without solvent is subjected to decompression distillation and purification directly, and needed acyl chloride is obtained; reaction liquid which is reacted with the solvent is subjected to decompression distillation to remove the solvent, and needed acyl chloride is obtained. According to the preparation method of acyl chloride, no catalyst is added, the risks that in the synthesizing process, due to the fact that the catalyst is dissolved, color of the finial product of acyl chloride is increased, and the catalyst is remained in late products are avoided, after the reaction is finished, high-quality acyl chloride can be obtained through decompression distillation, and the technological process is simple; due to the fact that in the whole technological process, except for absorbable and available phosgene, hydrogen chloride and carbon dioxide, no other three waste is discharged, the preparation method of acyl chloride is environmentally friendly, and the good implement value is achieved.
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Paragraph 0054; 0055
(2016/11/28)
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- FLUOROALKANE DERIVATIVE, GELATOR, LIQUID CRYSTALLINE COMPOUND AND GEL COMPOSITION
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PROBLEM TO BE SOLVED: To provide a novel fluoroalkane derivative, a gelator comprising a compound thereof, a gel composition comprising the gelator, and a liquid crystalline compound comprising the novel fluoroalkane derivative. SOLUTION: The present invention provides a fluoroalkane derivative represented by general formula (1): R2-L1-Ar1-X1-R1 (where, Ar1 is a substituted or unsubstituted divalent aromatic group having 6 to 30 nuclear atoms, R1 is a saturated or unsaturated monovalent hydrocarbon group having a perfluoroalkyl group with 2 to 22 carbon atoms, X1 is an oxygen atom, a sulfur atom or a group represented by -SO2-, R2 is a specific monovalent group, L1 is a group represented by -COO- or a group represented by -OCO- depending on the type of R2). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0140-0141
(2017/01/05)
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- The amide compound, and method for using same Fungiproof midlewproofing agent
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PROBLEM TO BE SOLVED: To provide an amide compound, a mold prevention agent, and a mold prevention method using the mold prevention agent, each of which exhibits excellent mold prevention effect and performs reduction in manuaafcturing cost.SOLUTION: The mold prevention agent includes and amide compound obtained at least by reacting a monocarboxylic amide compound represented by general formula (1) or a saturated or unsaturated nitrogen-containing 5- to 6-membered heterocycle (such as an imidazole ring and a piperidine ring) with 6 to 13C alkylene group-containing dicarboxylic acid as an effective component: general formula (1) (wherein, A denotes an unsaturated 5-membered heterocycle which may have a substituent; Ydenotes an 8 to 13C alkylene group; and Z denotes a methyl group or vinyl group).
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Paragraph 0185
(2016/11/07)
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- Using the same method and termiteproof termiteproof agent
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PROBLEM TO BE SOLVED: To provide a termite-proofing agent exhibiting high termite-proofing effect and enabling its own production cost to be reduced, and to provide a termite-proofing method using the same. SOLUTION: The termite-proofing agent is provided, which includes an amide compound represented by general formula (1). In general formula (1), either one of X1and X2is a halogen atom, alkyl or (substituted) phenyl, the other being H; alternatively, the X1and X2are optionally bound to each other to form a (substituted) saturated or unsaturated 5- or 6-membered ring; Y is a 6-14C alkylene group; and Z is amido group including methyl, vinyl or two disubstituted groups. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0139
(2016/12/16)
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- AMIDE COMPOUND, ANTIFUNGAL AGENT AND ANTIFUNGAL METHOD USING THE SAME
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PROBLEM TO BE SOLVED: To provide an amide compound and an antifungal agent that express excellent antifungal action, and can reduce production cost, and an antifungal method using the antifungal agent. SOLUTION: An antifungal agent comprises, as its active ingredient, an amide compound represented by the general formula (2) (where B represents an optionally substituted saturated or unsaturated heterocyclic 5-6 membered ring; C represents an optionally substituted saturated or unsaturated heterocyclic 5-6 membered ring; and Y2 represents an alkylene group having 6-13 carbon atoms). COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0184
(2018/10/04)
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- Synthesis and binding profile of haloperidol-based bivalent ligands targeting dopamine D2-like receptors
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Homodimers of dopamine D2-like receptors are suggested to be of particular importance in the pathophysiology of schizophrenia and, thus, serve as promising targets for the discovery of atypical antipsychotics. This study describes the development of a series of novel bivalent molecules with a pharmacophore derived from the dopamine receptor antagonist haloperidol. These dimers were investigated in comparison to their monomeric analogues for their D2long, D2short, D3, and D4 receptor binding and the ability to bridge two neighboring receptor protomers. Radioligand binding studies provided diagnostic insights when Hill slopes close to two for the bivalent ligand 13 incorporating 22 spacer atoms and a comparative analysis with monovalent control ligands indicated a bivalent binding mode with a simultaneous occupancy of two neighboring binding sites.
- Salama, Ismail,L?ber, Stefan,Hübner, Harald,Gmeiner, Peter
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supporting information
p. 3753 - 3756
(2014/09/16)
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- Synthesis, thermal, and photocrosslinking studies of thermotropic liquid crystalline poly(benzylidene-ether)esters containing α,β-unsaturated ketone moiety in the main chain
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A series of poly(benzylidene-ether)esters containing a photoreactive benzylidene chromophore in the main chain were synthesized from 2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone (BHMBCH) with various aliphatic and aromatic diacid chlorides by an interfacial polycondensation technique. The intrinsic viscosity of the synthesized homo and copolymers determined by Ubbelohde viscometer was found to be 0.12 to 0.17 dL/g. The molecular structure of the monomer and polymers was confirmed by FT-IR, 1H NMR, and 13C NMR spectral analyses. These polymers were studied for their thermal stability and photochemical properties. Thermal properties were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found that the polymers were stable up to 280 °C and start degrading thereafter. Increase in acid methylene spacer length decreased the thermal stability. The self-extinguishing property of the synthesized polymers was studied by calculating the limiting oxygen index (LOI) value using a Van Krevelen's equation. The influence of the length of methylene spacer on phase transition was investigated using DSC and odd-even effect has been observed. Hot-stage optical polarizing microscopic (HOPM) study showed that most of the polymers exhibited birefringence and opalescence properties. The photolysis of liquid crystalline poly(benzylidene-ether)esters revealed that α,β-unsaturated ketone moiety in the main chain dimerises through 2π + 2π cycloaddition reaction to form a cyclobutane derivative and leads to crosslinking.
- Muthusamy, Athianna,Balaji, Krishnasamy,Murugavel, Salem Chandrasekaran
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p. 1707 - 1715
(2013/04/24)
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- Titanium(IV) enolates of 2-nitrocarboxylic esters and their oxidative chlorinationa convenient route to α-chloro-α-nitrocarboxylates
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A new method for the synthesis of 2-chloro-2-nitrocarboxylic esters from 2-nitrocarboxylates is described. The procedure consists of the oxidative chlorination of titanium(IV) enolates of 2-nitro esters in the presence of ammonium nitrate. Esters of 2-chloro-2-nitrocarboxylic acids are formed in very good to quantitative yields. Application of this method for the chlorination of α,α′-dinitrodicarboxylates leads to α,α′- dichloro-α,α′-dinitrocarboxylic esters with high meso-diastereoselectivity. The absence of ammonium nitrate from the reaction mixture affects the reduction of nitro groups and leads to partial transformation of 2-nitrocarboxylic esters into 2-(hydroxyimino)carboxylates. Georg Thieme Verlag Stuttgart - New York.
- Ciez, Dariusz,Kalinowska-T?us?cik, Justyna
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supporting information; experimental part
p. 267 - 271
(2012/03/11)
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- Homobivalent ligands of the atypical antipsychotic clozapine: Design, synthesis, and pharmacological evaluation
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To date all typical and atypical antipsychotics target the dopamine D 2 receptor. Clozapine represents the best-characterized atypical antipsychotic, although it displays only moderate (submicromolar) affinity for the dopamine D2 receptor. Herein, we present the design, synthesis, and pharmacological evaluation of three series of homobivalent ligands of clozapine, differing in the length and nature of the spacer and the point of attachment to the pharmacophore. Attachment of the spacer at the N4′ position of clozapine yielded a series of homobivalent ligands that displayed spacer-length-dependent gains in affinity and activity for the dopamine D 2 receptor. The 16 and 18 atom spacer bivalent ligands were the highlight compounds, displaying marked low nanomolar receptor binding affinity (1.41 and 1.35 nM, respectively) and functional activity (23 and 44 nM), which correspond to significant gains in affinity (75- and 79-fold) and activity (9- and 5-fold) relative to the original pharmacophore, clozapine. As such these ligands represent useful tools with which to investigate dopamine receptor dimerization and the atypical nature of clozapine.
- McRobb, Fiona M.,Crosby, Ian T.,Yuriev, Elizabeth,Lane, J. Robert,Capuano, Ben
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supporting information; experimental part
p. 1622 - 1634
(2012/04/17)
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- Synthesis and binding affinity of novel mono- and bivalent morphinan ligands for κ, μ, and δ opioid receptors
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A novel series of homo- and heterodimeric ligands containing κ/μ agonist and μ agonist/antagonist pharmacophores joined by a 10-carbon ester linker chain were synthesized and evaluated for their in vitro binding affinity at κ, μ, and δ opioid receptors, and their functional activities were determined at κ and μ receptors in [35S]GTPγS functional assays. Most of these compounds had high binding affinity at μ and κ receptors (Ki values less than 1 nM). Compound 15b, which contains butorphan (1) at one end of linking chain and butorphanol (5) at the other end, was the most potent ligand in this series with binding affinity Ki values of 0.089 nM at the μ receptor and 0.073 nM at the κ receptor. All of the morphinan-derived ligands were found to be partial κ and μ agonists; ATPM-derived ligands 12 and 11 were found to be full κ agonists and partial μ agonists.
- Zhang, Bin,Zhang, Tangzhi,Sromek, Anna W.,Scrimale, Thomas,Bidlack, Jean M.,Neumeyer, John L.
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experimental part
p. 2808 - 2816
(2011/06/17)
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- A new class of star-shaped cholesteric liquid crystal containing a 1,3,5-trihydroxybenzene unit as a core
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A new class of star-shaped cholesteric liquid crystals were designed and synthesized, which used 1,3,5-trihydroxybenzene unit as a core and ω-cholesteric alkyl diacid monoester as mesogenic arm. Their chemical structures were confirmed by element analyses, FT-IR, and 1H NMR. The mesomorphic properties and thermal stability were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction measurements. The experimental results demonstrated that the mesogenic arm structures strongly affected the phase behavior. 4a did not show any liquid crystallinity, while 4b, 4c and 4d revealed reversible cholesteric phase transition. As the intermedius alkyl chain of the star-shaped compounds lengthened (from n = 2 to n = 8), their melting points decreased but mesomorphic temperature ranges increased. Focal conic texture, one of cholesteric phase can be observed in the liquid crystalline state.
- Yao, Dan-Shu,Zhang, Bao-Yan,Zhang, Wei-Wei,Tian, Mei
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- Active template synthesis of rotaxanes and molecular shuttles with switchable dynamics by four-component PdII-promoted Michael additions
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(Chemical Equation). Taking the Michael: Rotaxanes (see structure) and molecular shuttles are prepared in up to 99% yield by successive Pd II-promoted 1,4-conjugate additions in a one-pot four-component assembly process. This process represents the first active template reaction in which the template motif is retained in the interlocked product.
- Goldup, Stephen M.,Leigh, David A.,Lusby, Paul J.,McBurney, Roy T.,Slawin, Alexandra M. Z.
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supporting information; experimental part
p. 3381 - 3384
(2009/02/07)
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- Synthesis of novel bis-1,3,4-thiadiazoles, bis-1,2,4-triazoles and their antimicrobial activity
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Condensation of scbacic acid dihydrazide (1) with aryl/alkyl isothiocyanates (2a-g) gives bis-(N-aryl/alkylthiocarbamido)-scbacic acid diamides (3a-g), which on reaction with o-phosphoric acid yields l,8-bis-(2-aryl/alkylamino-l,3,4-thiadiazol-5-yl)-octanes (4a-g). 1,8-Bis-(3-mercapto-4-aryl/alkyl-1,2,4-triazol-5-yl)-octanes (5a-g) were obtained by a similar condensation of compounds (3a-g) with aqueous KOH, which on reaction with ethyl iodide in the form of dihydroiodides have been isolated (6a-g). These on basification with aq. ammonia solution afforded free bases (7a-g). Compounds (4a-g) on benzoylation with benzoyl chloride and NaOH affords benzoyl derivatives (8a-g). The structures of all these compounds were confirmed on the basis of elemental analysis and spectral data and evaluated for their antimicrobial activity against gram positive and gram negative bacteria.
- Burghate, Megha K.,Burghate,Berad
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body text
p. 561 - 565
(2009/08/15)
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- Ortho-substituted catechol derivatives: The effect of intramolecular hydrogen-bonding pathways on chloride anion recognition
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(Chemical Equation Presented) This paper reports a series of chloride anion receptors containing two catechol head groups connected through their ortho-positions via a spacer chain. The linking group chosen to attach the spacer chain to the catechol units has a major impact on the anion-binding potential of the receptor. Linking groups that are capable of forming stable six-membered intramolecular hydrogen-bonded rings with the catechol O-H groups significantly inhibit the ability of the catechol units to hydrogen bond to chloride anions. However, where the linking groups are only capable of forming five- or seven-membered intramolecular hydrogen-bonded rings, then anion binding via hydrogen bonding through the catechol O-H groups becomes a possibility. This process is solvent dependent; the presence of competitive solvent (e.g., DMSO-d6) disrupts the intramolecular hydrogen-bonding pattern and enhances anion binding relative to simple unfunctionalized catechol. The most effective receptor is that in which the hydrogen-bonding linker (-CH 2CONH-) is most distant from the catechol units and can only form a seven-membered intramolecular hydrogen-bonded ring. In this case, the receptor, which contains two catechol units, is a more effective chloride anion binder than simple unfunctionalized catechol, demonstrating that the two head groups, in combination with the N-H groups in the linker, act cooperatively and enhance the degree of anion binding. In summary, this paper provides insight into the hydrogen-bonding patterns in orthofunctionalized catechols and the impact these have on the potential of the catechol O-H groups to hydrogen bond to a chloride anion.
- Winstanley, Keith J.,Smith, David K.
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p. 2803 - 2815
(2008/02/01)
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- Hydrogen-bonding-driven preorganized zinc porphyrin receptors for efficient complexation of C60, C70, and C60 derivatives
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This paper describes the self-assembly of a new class of foldamer-based molecular tweezers, whose rigid folded conformations are stabilized by intramolecular hydrogen bonding. Two zinc porphyrin units are introduced to the ends of molecular tweezers Zn21 and Zn22, while three zinc porphyrin units are incorporated to the S-shaped bi-tweezers Zn33, which may be regarded as a combination of two Zn21 molecules. Due to the preorganized U-shaped feature, Zn21 and Zn22 are able to strongly complex C60, C70, and C60 derivative 25 in chloroform or toluene in a 1:1 binding stoichiometry, whereas Zn33, which possesses two tweezer units, complexes the guests in a 1:2 stoichiometry. More stable complex Zn33·24 is formed between Zn33 and 24, a linear molecule bearing two C60 moieties at the ends, as a result of the cooperative interaction of two binding sites. Chiral induction is observed for all the three receptors upon complexation with C60-incorporated chiral phenylalanine derivative 29, although the complexation of 29 by the folding receptors is pronouncedly weaker than that of C60 and 25 due to increased steric hindrance. The driving force for the formation of the complexes is the well established π-π stacking between the zinc porphyrin and fullerene units. The 1H and 13C NMR, UV-vis, fluorescent, and circular dichroism spectroscopy have been used to investigate the complexing behavior of the folding receptors and the fullerene guests. The association constants of the corresponding complexes in toluene and chloroform (if possible) have been evaluated with the UV-vis and fluorescent titration experiments.
- Wu, Zong-Quan,Shao, Xue-Bin,Li, Chuang,Hou, Jun-Li,Wang, Kui,Jiang, Xi-Kui,Li, Zhan-Ting
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p. 17460 - 17468
(2007/10/03)
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- Synthesis and characteriation of novel poly (ester amide)s containing benzthiazole heterocyclic ring
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The novel Poly (ester-amide)s (PEAs) were prepared by inrter-facial polycondensation of 5 - hydroxy - 2 - amino benzthiazole with various di-basic acid chlorides. The PEAs were characterized by elements analysis, IR spectra studies, Mn estimated by non aqueous conductometric titration and thermogravimetry. The electric conductivity of all the poly (ester amide)s PEAs was also measured at room temperature and it was found that the PEAs have semiconducting properties.
- Patel,Desai,Patel
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p. 203 - 208
(2007/10/03)
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- Behavior of Ruthenium Trisbipyridine-Anthraquinone Conjugates Connected with Alkyl Spacers in Homogeneous and Microheterogeneous Media
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A series of mononuclear Ru trisbypiridine complexes connected to an anthraquinone unit by a flexible alkyl chain of varying lengths and a bolaamphiphilic dinuclear ruthenium complex bearing an anthraquinone unit in the middle of alkyl chain spacers were synthesized. Their conformational preference in CH3CN and in dihexadecyl phosphate vesicles was probed by utilizing the intramolecular electron-transfer quenching of the metal-to-ligand charge-transfer excited state of the Ru center by the appended quinone moiety. The length of the alkyl chain spacer had little effect on the quenching efficiency in either medium. A marked difference in the quenching behavior was observed only in the case of the dinuclear Ru complex in vesicles. These results indicate that the bolaamphiphilic structure is necessary and effective for the set of immobilized molecules to take a stretched conformation spanning a bilayer membrane.
- Otsuki, Joe,Ogawa, Hiroyuki,Okuda, Naotoshi,Araki, Koji,Seno, Manabu
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p. 2077 - 2084
(2007/10/03)
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- Conception et synthese de chelatants du fer III pour le traitement de la chlorose ferrique
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New iron chelates containing pyrocatechol subunits bounded in α-position of a linear dicarboxylic acid are reported.The design of the structure and the choice of the synthetic scheme (with the help of Assisted Organic Synthesis) are presented.The six steps synthesis scheduled, needs the protection-deprotection of the carboxylic acids and the use of gaiacol preferably to pyrochatecol.The synthetic route is discussed.The individual steps and the characteristics of 20 reaction intermediates and products are described.The scope of the study is presented.
- Mhenni, F.,Bouraoui, A.,Mighri, Z.,Gallo, R.
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p. 824 - 829
(2007/10/02)
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- INTRAMOLECULAR END-TO-END REACTIONS OF PHOTOACTIVE TERMINAL GROUPS LINKED BY POLYMETHYLENE CHAINS.
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Intramolecular end-to-end reactions of a pair of photoactive terminal groups, dibenz left bracket b,f right bracket azepine (DBA) chromophores, linked by a series of polymethylene chains (DBA-CO(CH//2)//nCO-DBA, n equals 2-30) were studied by two different approaches. One approach is to measure the intramolecular deactivation rate constants of the excited triplet state of terminal DBA groups by the nanosecond laser photolysis and the other is to measure the intramolecular photocyclization rates of these bichromophoric compounds by the quantitative product analysis with GPC. The excited triplet state of the DBA group is the intermediate of the reaction.
- Ashikaga,Ito,Yamamoto,Nishijima
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p. 198 - 204
(2007/10/02)
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- Liquid-Crystalline Schiff's Base Polymers
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Liquid-crystal polymers are reported which are prepared from di-(p-formylphenyl)-α-ω-alkanedicarboxylates and p-phenylenediamine.Neither component forms a mesophase but the polymers are typical main-chain liquid crystal polymers.The synthesis of a series of such polymers is described, and the properties of the products are discussed.
- Al-Dujaili, Amar H.,Jenkins, D.,Walton, David R. M.
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- Magnetic, Spectral and Thermal Studies on Some New Polymeric Complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with Bis-phenylhydrazides of Suberic and Sebacic Acids
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Coordination polymers of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with bis-phenylhydrazides of sulberic acid and sebacic acid have been prepared.These polymers have been characterized on the basis of the elemental analysis, magnetic susceptibility, reflectance and infrared spectral, and thermogravimetric data.
- Juneja, H. D.,Munshi, K. N.
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p. 451 - 453
(2007/10/02)
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- Both-faces Hindered Porphyrins. Part 3. Synthesis and Characterization of Internally Five-co-ordinated Iron(II) Basket Handle Porphyrins derived from 5,10,15,20-Tetrakis(o-aminophenyl)porphyrin
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The synthesis of a series of so-called amide 'hanging base' porphyrins (10), (14) and (18), derived from 5,10,15,20-tetrakis(o-aminophenyl)porphyrin (αβαβ-atropisomer) (3), in which one of the faces is hindered by an alkylene or an arylene-p-bisalkylene bridge and the other face is bridged by a pyridine-3,5-diyl-bisalkylene or an imidazolyl-alkylene chain, is described.The structural assignment of the various compounds is based on the 1H n.m.r. spectra of the free bases, and of their zinc(II) and iron(II) complexes.Unlike the ether 'hanging base' metalloporphyrins, the metallic ion of amide 'hanging base' porphyrins is actually five-co-ordinated by the proximal base.Furthermore, not only is the equilibrium pyridine plane orientation dependent on the length of its linking chain, but the bridging forces the amide protons to point toward the centre of the macrocycle core.These structural properties are potential factors which may affect the binding of dioxygen.The synthesis of a bis-pyridine 'basket handle' porphyrin is also reported.
- Momenteau, Michel,Mispelter, Joel,Loock, Bernard,Lhoste, Jean-Marc
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p. 221 - 232
(2007/10/02)
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