- Iron and Manganese Complexes of 2-Carbonyl Pyrrolyls: Scorpionate Sandwich Anions and Extended Structures
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Attempts to synthesize complexes of Fe and Mn(II) with 2-amidopyrrolyl ligands (N-O) were unsuccessful, and only small amounts of the trivalent tris complexes M(N-O)3 were detected, although unusually in the case of Fe(III) a fac structure is observed. In contrast the 2-benzoylpyrrolyl systems give M(II) complexes, and in all instances thus far where Na+ is present, a scorpionate fac-[MII(N-O)3]- unit self-assembles into sandwich anions [MII(N-O)3Na(O-N)3MII]- in which the central metal is efficiently encapsulated by interdigitation of the aryl units. Extended structures are readily made through the use of a 2-(4-pyridinoyl)pyrrolylamide ligand. When Li+ is used, the scorpionate ligand is not assembled, and instead [M(N-O)2] units give rhombic 2D grids. The Fe system displays spin-crossover at 120 K. (Figure Presented).
- Li, Lihong,Clarkson, Guy J.,Lees, Martin R.,Howson, Suzanne E.,Tan, Sze-Yin,Turner, Scott S.,Scott, Peter
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- Multi-arm ionic liquid crystals formed by pyridine-mesophase and copper phthalocyanine
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Phthalocyanine emerged as a promising molecular component for photoreceptors because of their high extinction coefficients, stability, and energy band gaps well-matched to the incident solar spectrum. The cavity in the center can be occupied by dozens of cation types to form metallo-phthalocyanines which show a number of special properties such as electrical, optical, non-linear optical and opto-electronic. A kind of novel multi-arm ionic liquid crystalline materials combined the characteristics of liquid crystals with phthalocyanine were prepared using copper phthalocyanine as a matrix, [1,1′-biphenyl]-4,4′-diyl diisonicotinate or cyclohexane-1,4-diyl diisonicotinate as a mesogen, and different ions (B-SO3 ?, C-SO3 ?, H2PO4 ? and BF4 ?) as counterions. The mesomorphic properties of these ionic liquid crystals were investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction measurements. The copper phthalocyanine-based multi-arm ionic liquid crystals showed excellent electrical conductivity (the optimum value of conductivity can reach 0.0248 S/cm) because of their ionic channels and π-π stacking structure. This materials might provide a promising application prospect for electronic or optoelectronic applications.
- Kong, Shengwen,Wang, Xiaodong,Bai, Lu,Song, Ying,Meng, Fanbao
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- Synthesis and the crystal structures of N-(2-nitroxyethyl)isonicotinamide and its complexes with PdCl2 and PtCl2 as potential antitumor medicines
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Previously unknown N-(2-nitroxyethyl)isonicotinamide was synthesized by the reaction of isonicotinoyl chloride with 2-nitroxyethylamine and was used as a ligand in the reactions with PdCl2 and PtCl2 to prepare new complexes, viz., trans-bis[(2-nitroxyethyl)isonicotinamide-N]dichloropalladium(11) and ci.s-bis[(2-nitroxyethyl)isonicotinamide-N]dichloroplatinum(11), respectively. The structures of the ligand and the resulting complexes were established by X-ray diffraction analysis.
- Fedorov,Golovina,Fadeev,Strukov,Kedrov,Shilov,Boiko,Atovmyan
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- Synthesis and antimicrobial characteristics of novel biocides, 4,4'- (1,6-hexamethylenedioxydicarbonyl)bis(1-alkylpyridinium iodide)s
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Potent new biocides against both bacteria and fungi, 4,4'-(1,6- hexamethylenedioxydicarbonyl)bis(1-alkylpyridinium iodide)s (4DOCBP-6,n) (alkyl chain length, n=8, 10, 12, 14, 16 and 18) were synthesized. 4DOCBP- 6,n is a bis-quaternary ammonium compound (bis-QAC) and has a symmetrical dimeric structure which is composed of two alkylpyridinium iodides connected with a hexamethylenedioxydicarbonyl chain. 4DOCBP-6,10 and 4DOCBP-6,12 exhibited wide and effective antimicrobial spectra, compared with those of typical bactericides, N-dodecylpyridinium iodides (P-12) and benzyldimethyldodecylammonium chloride (BAC), or a popularly-used fungicide, 2-(4-thiazolyl)benzimidazole (TBZ). Their superior properties would be due to the unique dimeric structure which contains two active moieties in a molecule.
- Maeda, Takuya,Manabe, Yuki,Yamamoto, Masashi,Yoshida, Munehiro,Okazaki, Kiyo,Nagamune, Hideaki,Kourai, Hiroki
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- Direct electrochemistry of cytochrome c at modified Si(100) electrodes
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This paper demonstrates the direct electron transfer between the heme moiety of horse hearth cytochrome c and a pyridinyl group on self-assembled-monolayer-modified Si(100) electrodes. Self-assembled monolayers (SAMs) containing the putative receptor ligand were prepared by a step-wise procedure using "click" reactions of acetylene-terminated alkyl monolayers and isonicotinic acid azide derivatives. Unoxidized Si(100) electrodes, possessing either isonicotinate or isonicotinamide receptor ligands, were characterized using X-ray photoelectron spectroscopy, contact-angle goniometry, cyclic voltammetry, and electrochemical impedance spectroscopy. The ability of isonicotinic acid terminated layers to coordinatively bind the redox center of cytochrome c was found to be restricted to pyridinyl assemblies with a paraester linkage present. The protocol detailed here offers an experimentally simple modular approach to producing chemically well-defined SAMs on silicon surfaces for direct electrochemistry of a well-studied model redox protein.
- Ciampi, Simone,Gooding, J. Justin
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- Novel photo-polymerizable chiral hydrogen-bonded self-assembled complexes: Preparation, characterization and the utilization as a thermal switching reflective color film
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In this study, novel photopolymerizable chiral hydrogen-bonded self-assembled complexes (PCHSCs) were fabricated, which were derived from photopolymerizable 4-(6-acryloyloxyhexyloxy) benzoic acid (AHBA, proton donor) and chiral pyridine derivatives (proton acceptor). Their structures were characterized by fourier transform infrared (FT-IR) and the proton nuclear magnetic resonance (1H-NMR) spectoscopy. The thermal stability, phase behaviors and helical twisted power (HTP) characteristics of the PCHSC were investigated by measuring the variable-temperature FT-IR spectrum, differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and the Cano wedge. The results demonstrate that all the PCHSCs have good thermal stability within a temperature range, and the pitch length of all the cells containing the PCHSCs increases with increasing temperature, which is due to the fact that the HTP values of all the PCHSCs decrease with an increase of temperature. What's more, the introduction of AHBA leads to chiral enhancement of the PCHSCs. Based on the above results, a polymer stabilized cholesteric liquid crystals (PSCLCs) composite with the above PCHSCs was prepared and the thermal-optical characteristics of the PSCLCs film were investigated. The results confirm that the reflective wavelength of the PSCLCs film before and after irradiation can be thermally switched to reflect green and red color from the initial state reflecting a blue/green color with the temperature increasing from 30 °C to 75 °C. On the basis of this mechanism, the novel material in this study can be used as optical/photonic paper, optical sensors and LCs displays, etc.
- Chen, Fengjin,Guo, Jinbao,Qu, Zhijian,Wei, Jie
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- Tuning gel state properties of supramolecular gels by functional group modification
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The factors affecting the self-assembly process in low molecular weight gelators (LMWGs) were investigated by tuning the gelation properties of a well-known gelator N-(4-pyridyl)isonicotinamide (4PINA). The N—H···N interactions responsible for gel formation in 4PINA were disrupted by altering the functional groups of 4PINA, which was achieved by modifying pyridyl moieties of the gelator to pyridyl N-oxides. We synthesized two mono-N-oxides (INO and PNO) and a di-N-oxide (diNO) and the gelation studies revealed selective gelation of diNO in water, but the two mono-N-oxides formed crystals. The mechanical strength and thermal stabilities of the gelators were evaluated by rheology and transition temperature (Tgel) experiments, respectively, and the analysis of the gel strength indicated that diNO formed weak gels compared to 4PINA. The SEM image of diNO xerogels showed fibrous microcrystalline networks compared to the efficient fibrous morphology in 4PINA. Single-crystal X-ray analysis of diNO gelator revealed that a hydrogen-bonded dimer interacts with adjacent dimers via C—H···O interactions. The non-gelator with similar dimers interacted via C—H···N interaction, which indicates the importance of specific non-bonding interactions in the formation of the gel network. The solvated forms of mono-N-oxides support the fact that these compounds prefer crystalline state rather than gelation due to the increased hydrophilic interactions. The reduced gelation ability (minimum gel concentration (MGC)) and thermal strength of diNO may be attributed to the weak intermolecular C—H···O interaction compared to the strong and unidirectional N—H···N interactions in 4PINA.
- Ghosh, Dipankar,Mulvee, Matthew T.,Damodaran, Krishna K.
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- Synthesis and pharmacological evaluation of novel selective MOR agonist 6β-pyridinyl amidomorphines exhibiting long-lasting antinociception
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It was previously reported that 6β-aminomorphinan derivatives show high affinity for opiate receptors. Novel 6β-heteroarylamidomorphinanes were designed based on the MOR selective antagonist NAP. The 6β-aminomorphinanes were prepared by stereoselective Mitsunobu reaction and subsequently acylated with nicotinic acid and isonicotinic acid chloride hydrochlorides. The receptor binding and efficacy were determined in vitro and the analgesic activity was studied in vivo. The in vitro studies revealed moderate selectivity for the MOR. At least two compounds in this series exhibited a long-lasting analgesic response when administered subcutaneously and intracerebroventricularly. When the substances were given intracerebroventricularly to mice, they showed analgesic potency comparable to morphine.
- Urai, ákos,Váradi, András,Sz?cs, Levente,Komjáti, Balázs,Le Rouzic, Valerie,Hunkele, Amanda,Pasternak, Gavril W.,Majumdar, Susruta,Hosztafi, Sándor
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supporting information
p. 152 - 157
(2017/02/05)
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- Design, synthesis and biological evaluation of N-(4-alkoxy-3-cyanophenyl)isonicotinamide/nicotinamide derivatives as novel xanthine oxidase inhibitors
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A series of N-(4-alkoxy-3-cyanophenyl)isonicotinamide/nicotinamide derivatives was designed, synthesized and evaluated for inhibitory potency in vitro against xanthine oxidase. The isonicotinamide series was considerably more effective than the nicotinamide series. SARs analysis revealed that the isonicotinoyl moiety played a significant role on the inhibition and that a benzyl ether tail (e.g., ortho-cyanobenzoxy) linked to the benzonitrile moiety benefits the inhibitory potency. Among these compounds, 10q (IC50 = 0.3 μM) was identified to be the most potent in this work and was observed to be 28.3-fold more potent than allopurinol but 20-fold less potent than topiroxostat. The Lineweaver-Burk plot showed that 10q acted as a mixed-type inhibitor on xanthine oxidase. Molecular modeling provided a reasonable explanation for the SARs observed in this study.
- Zhang, Ting-jian,Li, Song-ye,Wang, Lin,Sun, Qi,Wu, Qing-xia,Zhang, Yi,Meng, Fan-hao
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p. 362 - 372
(2017/10/16)
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- Pyridine derivatives; New efficient additives in bromide/tribromide electrolyte for dye sensitized solar cells
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In this work, two new inexpensive pyridine derivatives, propyl isonicotinate (PIN) and isopropyl isonicotinate (IPIN), have been synthesized through a simple and low cost method and for the first time, they have been applied as effective additives in bromide/tribromide electrolyte in dye sensitized solar cells (DSSCs). Although the iodide/triiodide redox shuttle shows remarkable performance in DSSCs, but bromide/tribromide couple has a more positive redox potential in comparison to this couple. Therefore, it is good idea to design dyes whose HOMO and LUMO levels match with the redox potential of bromide/tribromide and the conduction band (CB) of TiO2, respectively. We have synthesized 3-(4-carbazole-9-yl-phenyl)-2-cyano-acrylic acid (TC301) and 2-cyano-3-(4-(3,6-di-tert-butyl-9H-carbazole-9-yl)phenyl) acrylic acid (TC302) as two carbazole dyes and applied them with modified electrolyte in DSSCs. The influence of PIN and IPIN additives in bromide/tribromide redox electrolyte on the DSSC performances is investigated. In comparison to electrolyte without additive, adding 0.5 M of these additives to the electrolyte solution leads to an increase in the open circuit voltage (Voc) and short current density (Jsc), consequently the energy conversion efficiency (η) improves. Electrochemical impedance spectroscopy show that the enhancement in Voc is due to increasing electron density in the CB of TiO2 so that a shift in the Fermi level (EF) occurs. It leads to a suppression in electron recombination that has beneficial effect on the Voc. Furthermore, cyclic voltammetry results reveal that PIN and IPIN has similar effect mechanisms to 4-tert-butylpyridine (TBP) additive in the DSSCs. Our findings show that TBP can be replaced with PIN and IPIN in the DSSCs.
- Bagheri, Omid,Dehghani, Hossein,Afrooz, Malihe
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p. 86191 - 86198
(2015/11/03)
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- Binuclear dichlorido(η6-p-cymene)ruthenium(II) complexes with bis(nicotinate)- And bis (isonicotinate)-polyethylene glycol ester ligands
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Neutral binuclear ruthenium complexes 1-8 of the general formula [{RuCl2(η6-p-cym)}2 μ-(N∩N)] (N∩N=bis(nicotinate)- and bis (isonicotinate)-polyethylene glycol esters: (3-py)COO(CH2CH2O)nCO(3-py) and (4-py)COO(CH2CH2O)nCO(4-py), n =1-4), as well as mononuclear [RuCl2(η6-p-cym)((3-py)COO(CH2CH2OCH3)-κN)], complex 9, were synthesized and characterized using elemental analysis and electrospray ionization high-resolution mass spectrometry, infrared, 1H NMR and 13C NMR spectroscopies. Stability of the binuclear complexes in the presence of dimethylsulfoxide was studied. Furthermore, formation of a cationic complex containing bridging pyridine-based bidentate ligand was monitored using 1H NMR spectroscopy. Ligand precursors, polyethylene glycol esters of nicotinic (L1·2HCl-L4·2HCl and L9·HCl) and isonicotinic acid dihydrochlorides (L5·2HCl-L8·2HCl), binuclear ruthenium(II) complexes 1-8 and mononuclear complex 9 were tested for in vitro cytotoxicity against 518A2 (melanoma), 8505C (anaplastic thyroid cancer), A253 (head and neck tumour), MCF-7 (breast tumour) and SW480 (colon carcinoma) cell lines.
- Eichhorn, Thomas,Hey-Hawkins, Evamarie,Maksimovi-Ivani, Danijela,Moji, Marija,Schmidt, Jürgen,Mijatovi, Sanja,Schmidt, Harry,Kaluderovi, Goran N.
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- Synthesis of novel chiral ionic liquids based on (-)-menthyl isonicotinate
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(Chemical Equation Presented) Thirteen novel chiral ionic liquids (CILs) containing the (-)-menthyl group can be easily prepared from isonicotinic acid with yields of 35-90%. The properties and characterization of these compounds were discussed and the alternation of optical rotation was analyzed. Copyright Taylor & Francis Group, LLC.
- Miao, Chengping,Tu, Xiaohua,Xiang, Ziwei,Wu, Jianyi
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experimental part
p. 2555 - 2563
(2012/07/30)
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- Identification and development of an efficient route to SB-649915
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The discovery and development of an efficient manufacturing route to the SSRI-5-HT1A receptor antagonist 6-[(1-{2-[(2-methyl-5-quinolinyl)oxy]ethyl}-4- piperidinyl)methyl]-2H-1,4-benzoxazin-3(4H)-one (SB-649915) 1 is described. The existing route to 1 involved coupling quinoline 6 with piperidine 5 and was considered lengthy as a consequence of the nine synthetic steps required to prepare 5. Two new routes to the key piperidine intermediate 5 are identified which deliver this compound in five and two steps respectively, from readily available materials using novel lithiation and Friedel-Crafts methodology respectively. The latter of these two routes was successfully demonstrated at 5 L scale to deliver 700 g of 5. Development to the methanesulfonate 34, an alternative to quinoline 6, is also described as is the final alkylation of piperidine 5 with this methanesulfonate 34 to deliver SB-649915 1.
- Armitage, Mark,Bret, Guillaume,Choudary, Bernie M.,Kingswood, Mike,Loft, Mike,Moore, Steve,Smith, Steve,Urquhart, Michael W. J.
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p. 1626 - 1634
(2013/02/22)
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- Phase transfer-catalyzed, one-pot synthesis of some novel N-pyrimidinyl-N'-nicotinyl thiourea derivatives
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A new series of acyl thiourea derivatives were synthesized in one-pot using PEG-600 as the phase transfer catalyst (PTC). The structures of title compounds were characterized by 1H NMR, IR, MS, and elemental analysis. In addition, the fungicidal activity of the acyl thiourea derivatives were tested, which showed that most of them exhibit moderate activity. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Liu, Xing-Hai,Tan, Cheng-Xia,Weng, Jian-Quan
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experimental part
p. 552 - 557
(2011/05/07)
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- Desymmetrization of 3,3′-bis(acylamino)-2,2′-bipyridine-based discotics: The high fidelity of their self-assembly behavior in the liquid-crystalline state and in solution
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Two novel nonsymmetrical disc-shaped molecules 1 and 2 based on 3,3′-bis(acylamino)-2,2′-bipyridine units were synthesized by means of a statistical approach. Discotic 1 possesses six chiral dihydrocitronellyl tails and one peripheral phenyl group, whereas discotic 2 possesses six linear dodecyloxy tails and one peripheral pyridyl group. Preorganization by strong intramolecular hydrogen bonding and subsequent aromatic interactions induce self-assembly of the discotics. Liquid crystallinity of 1 and 2 was determined with the aid of polarized optical microscopy, differential scanning calorimetry and X-ray diffraction. Two columnar rectangular mesophases (Colr) have been identified, whereas for C3-symmetrical derivatives only one Colr mesophase has been found.[1] In solution, the molecularly dissolved state in chloroform was studied with 1H NMR spectroscopy, whereas the self-assembled state in apolar solution was examined with optical spectroscopy. Remarkably, these desymmetrized discotics, which lack one aliphatic wedge, behave similar to the symmetric parent compound. To prove that the stacking behavior of discotics 1 and 2 is similar to that of reported C3-symmetrical derivatives, a mixing experiment of chiral 1 with C3-symmetrical 13 has been undertaken; it has shown that they indeed belong to one type of self-assembly. This helical J-type self-assembly was further confirmed with UV/Vis and photoluminescence (PL) spectroscopy. Eventually, disc 2, functionalized with a hydrogen-bonding acceptor moiety, might perform secondary interactions with molecules such as acids.
- Van Houtem, Michel H. C. J.,Martin-Rapun, Rafael,Vekemans, Jef A. J. M.,Meijer
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experimental part
p. 2258 - 2271
(2010/07/05)
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- Design and synthesis of eugenol derivatives, as potent 15-lipoxygenase inhibitors
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A group of 4-allyl-2-methoxyphenol (eugenol) esters were designed, synthesized, and evaluated as potential inhibitors of soybean 15-lipoxygenase (SLO). Compounds 4c, 4d 4f, 4p, and 4q showed the best IC50 in SLO inhibition (IC50 = 1.7, 2.3, 2.1, 2.2, and 0.017 μM, respectively). All compounds were docked into SLO active site and showed that allyl group of compounds is oriented toward the iron atom in the active site of SLO. It is assumed that lipophilic interaction of ligand-enzyme would be in charge of inhibiting the enzyme activity. The selectivity of eugenol derivatives in inhibiting 15-HLOb was also compared with 15-HLOa by molecular modeling and multiple alignment techniques.
- Sadeghian, Hamid,Seyedi, Seyed Mohammad,Saberi, Mohammad Reza,Arghiani, Zahra,Riazi, Mehdi
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p. 890 - 901
(2008/09/17)
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- Photophysics of a series of efficient fluorescent pH probes for dual-emission-wavelength measurements in aqueous solutions
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This paper evaluates the 5-aryl-2-pyridyloxazole backbone to engineer donor-acceptor fluorescent pH probes after one- or two-photon absorption. Parent fluorophores, as well as derivatives that can be used to label biomolecules, can be easily obtained in good yields. These molecules exhibit a large one-photon absorption in the near-UV range, and a strong fluorescence emission that covers the whole visible domain. The 5-aryl-2-pyridyloxazole derivatives also possess significant cross sections for two-photon absorption. Upon pyridine protonation, large shifts were observed in the absorption spectra after one- and two-photon excitation, as well as in the emission spectra. This feature was used to measure the pKa of the investigated compounds that range between 2 and 8. In most of the investigated derivatives, the pKa increased upon light excitation and protonation exchanges took place during the lifetime of the excited state, as shown by phase-modulation fluorometry analysis. Several 5-aryl-2-pyridyloxazole derivatives are suggested as efficient probes to reliably measure the pH of aqueous solutions by means of ratiometric methods that are dependent on fluorescence emission.
- Charier, Sandrine,Ruel, Odile,Baudin, Jean-Bernard,Alcor, Damien,Allemand, Jean-Francois,Meglio, Adrien,Jullien, Ludovic,Valeur, Bernard
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p. 1097 - 1113
(2007/10/03)
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- PYRAZOLOPYRIDINE DERIVATES
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New compounds of formula (I) and the salts, solvates and prodrugs thereof, wherein the meanings for the various substituents are as disclosed in the description. These compounds are useful as p38 kinase inhibitors.
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- A simple method for synthesis of active esters of isonicotinic and picolinic acids
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A method for preparation of the p-nitrophenyl-, N-hydroxysuccinimidyl- and pentafluorophenyl esters of isonicotinic and picolinic acids from the corresponding acids is reported.
- Christensen, Jorn B.
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- Poly(oxyalkylene) pyridyl and piperidyl esters and fuel compositions containing the same
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A poly(oxyalkylene)pyridyl or piperidyl ester having the formula: or a fuel-soluble salt thereof; wherein A is a nitrogen-containing ring selected from the group consisting of 3-pyridyl, 4-pyridyl, 3-piperidyl and 4-piperidyl; R1 and R2 are independently hydrogen or lower alkyl having 1 to about 6 carbon atoms and each R1 and R2 is independently selected in each -O-CHR1-CHR2- unit; R3 is hydrogen, alkyl having 1 to about 100 carbon atoms, phenyl, aralkyl having about 7 to about 100 carbon atoms or alkaryl having about 7 to about 100 carbon atoms; x is an integer from 0 to 4; and n is an integer from about 5 to about 100. The poly(oxyalkylene)pyridyl and piperidyl esters of the present invention are useful as fuel additives for the prevention and control of engine deposits.
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- (+)-cis-4,5,7a,8,9,10,11,11a-Octahydro-7H-10-methylindolonaphthyridine: A 5-HT2C/2B Receptor Antagonist with Low 5-HT2A Receptor Affinity
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The indolonaphthyridine 8 is described as a selective 5-HT2C/2B vs 5-HT2A receptor antagonist.The compound was synthesized in seven steps starting from indoline and isonicotinic acid chloride.The key step is a photocyclization of the indolinyl tetrahydropyridinocarbamic acid ethyl ester 4 to the cis-octahydroindolonaphthyridinecarbamic acid ethyl ester 5.The synthesis was accomplished by reduction with aluminum hydride and racemic resolution.The indolonaphthyridine 8 exerted the binding profile of a selective 5-HT2C receptor ligand (pKD 7.8) and behaved as an antagonist on the 5-HT-induced accumulation of inositol phosphates in pig choroid plexus cells (pKB 7.13).Compound 8 dose-dependently inhibited the ACTH response to MK-212 in rats and the MK-212-induced hypophagic effect with an ID50 value of 0.3 mg/kg sc.Compound 8 acted as a 5-HT2B receptor antagonist at the rat stomach fundus with a pKB value of 7.34.
- Nozulak, Joachim,Kalkman, Hans O.,Floersheim, Philipp,Hoyer, Daniel,Schoeffter, Philipp,Buerki, Hans R.
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- TRANSFORMATIONS OF GLYCYRRHIZIC ACID. IX.* SYNTHESIS OF NEW ACYLATES
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New esters of a triterpene glycoside, glycyrrhizic acid, were synthesized by acylating the hydroxy groups of the carbohydrate moiety of the acid or its derivatives (trimethyl ester, trisodium, tripotassium, and monoammonium salts) with aromatic acid chlorides.Depending on the reaction conditions and acylating agents, either complete acylation of the acid occurs, or di- or trisubstituted esters and trimethyl ester of glycyrrhizic acid are formed.The following acylates were synthesized: trimethyl di-O-mesityl-, di-O-(o-nitro)benzenesulfonyl-, and penta-O-(p-nitro)-benzoylglycyrrhizates; penta-O-salicyloyl-, -acetylsalicyloyl-, -cinnamoyl-, -(p-methoxy)cinnamoyl-, di-O-(2,4-dinitro)benzoyl-, -isonicotinoyl-, -nicotinoyl-, and tri-O-acetylsalicyloyl-glycyrrhizic acids.
- Baltina, L. A.,Serdyuk, N. G.,Kondratenko, R. M.,Tolstikov, G. A.,Vasil'eva, E. V.
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p. 1809 - 1815
(2007/10/03)
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- SYNTEZA I BADANIE FARMAKOLOGICZNE NOWYCH POCHODNYCH TETRAHYDROIZOCHINOLINY
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The synthesis of tetrahydroizochinolin and izonicotin acid derivatives is described.Yields, elementary analysis and spectral data (IR) are given in Table 1.
- Gutkowska, Bozenna,Hellmann, Ewa,Kostowski, Wojciech,Krzascik, Pawel
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p. 243 - 248
(2007/10/02)
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- Syntheses and Photophysical Properties of Some 5(2)-Aryl-2(5)-(4-pyridyl)oxazoles and Related Oxadiazoles and Furans
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A number of 5-aryl-2-(4-pyridyl)oxazoles, a 2-aryl-5-(4-pyridyl)oxazole, the related oxadiazole and furan, several 2-(4-pyridyl)cycloalkanooxazoles, and many of their quaternary salts were prepared.No single standard synthesis was effective for preparation of more than a few of the 25 free bases described; methods often unique to a base were employed.Minor variations in structure sometimes produced large differences in absorption and emission wavelengths, as well as in the magnitude of the extinction coefficient.The salts are of interest as laser dyes, scintillation fluors, biological stains, and shifters for luminescent solar concentrators.
- Hall, J. Herbert,Chien, Joseph Yuming,Kauffman, Joel M.,Litak, Peter T.,Adams, Jeffrey K.,et al.
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p. 1245 - 1273
(2007/10/02)
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- Substitutions on Pyridines Activated by Oxazolines via Nucleophilic Additions or Metalation-Alkylation
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Pyridyloxazolines, derived from nicotinic acid or isonicotinic acid, have been shown to metalate at the 4- and 3-positions, respectively.These react with a variety of electrophiles to provide 4- and 3-substituted pyridines in good yield.Alternatively, 3-pyridyloxazolines, when treated with organolithium or Grignard reagents, give addition to the 4-position and provide a series of 4-substituted 1,4-dihydropyridines.
- Meyers, A. I.,Gabel, Richard A.
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p. 2633 - 2637
(2007/10/02)
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- THE MASS SPECTRAL FRAGMENTATION BEHAVIOR OF PYRIDINE CARBOXYLIC AND THIOCARBOXYLIC ACID ESTERS
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The mass spectral fragmentation behavior of pyridine carboxylic acid and thioacid methyl esters shows several peculiarities not observed with other aromatic esters, viz., i.a., (a) COOCH3 groups in α-position are involved in rearrangement processes under participation of N; (b) neighboring COOCH3 groups fragment by ortho-effects; (c) COSCH3, CSOCH3 and CSSCH3 groups suffer complex rearrangements leading to, e.g. loss of CO, CH2CO or S2 from M+, especially when located in α-position.
- Budzikiewicz, H.,Lange, E.,Ockels, W.
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