- Synthesis, in-vitro, in-vivo anti-inflammatory activities and molecular docking studies of acyl and salicylic acid hydrazide derivatives
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Over the course of time several drugs have been synthesized and are available in market for the treatment of inflammation. However, they were unable to cure effectively and associated with side effects. To effectively deal with such diseases, heterocycles and their derivatives have gained their special position. For this reason 1,3,4-oxadiazole (15–16), 1,2,4-triazole (17–18), Schiff base (19–24) and 3,5-disubstituted pyrazole (25) derivatives were synthesized starting from salicylic acid and acyl acid hydrazides (12–14) as COX-1 and COX-2 inhibitors. In vivo anti-inflammatory activities were also tested by carrageenan-induced mice paw edema against albino mice of any sex. Structures of all the synthesized compounds were confirmed by FT-IR and 1H NMR analysis. Schiff base derivative of 4-amiontirazole (24) with IC50 value of 1.76 ± 0.05 (COX-2) and 117.8 ± 2.59 emerged as potent COX-2 inhibitor. Furthermore, we also performed in-vivo anti-inflammatory investigations by using carrageenan induced paw edema test. From in-vivo anti-inflammatory activities, it was found that after 1 h the maximum percentage inhibition 15.8% was observed by compound 14 which is comparable with that of the standard drug followed by the compound 18 with percentage inhibition of 10.5%. After 3 h, the maximum percentage inhibition was observed by compound 18 with 22.2% and compound 14 with 16.7%. After 5 h the maximum percentage inhibition was observed by compound 18 with 29.4% followed by compound 16 with 23.5%. We further explore the mechanism of the inhibition by using docking simulations. Docking studies revealed that the selective COX-2 inhibitors established interactions with additional COX-2 enzyme pocket residues.
- Ali, Gowhar,Ashraf, Zaman,Hussain, Izhar,Khushal, Adil,Mumtaz, Amara,Munir, Abida,Rashid, Umer,Sadiq, Abdul,Saeed Jan, Muhammad,Saeed, Kiran,Ullah Mughal, Ehsan,Ullah, Rahim
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- The computer-aided discovery of novel family of the 5-HT6 serotonin receptor ligands among derivatives of 4-benzyl-1,3,5-triazine
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The work describes a discovery of new chemical family of potent ligands for the 5-HT6 serotonin receptors. During the search for new histamine H4 receptor antagonists among 1,3,5-triazine derivatives, compound 2 (4-benzyl-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine) was found. Compound 2, weakly active for the H4 receptor but fitted in 3/4 of pharmacophore features of the 5-HT6R ligand, occurred to be a moderate 5-HT6R agent, useful as a lead structure for further modifications. A series of new derivatives (3–19) of the lead 2 was synthesized, evaluated in the radioligand binding assay (RBA) and explored in comprehensive molecular modelling, including both pharmacophore- and structure-based approaches with docking to the homology model of 5-HT6R. The most active compounds displayed a potent affinity for the 5-HT6R in the nanomolar range (Ki?=?20–30?nM), some of them (4, 11 and 19) were tested in the rat forced swim test that revealed their antidepressant-like effect. SAR-analysis on the basis of both, RBA and docking results, indicated that action on the receptor is related to the hydrophobicity and the size of aromatic moiety substituted by a methylene linker at the position 4 of 1,3,5-triazine.
- ?a?ewska, Dorota,Kurczab, Rafa?,Wi?cek, Ma?gorzata,Kamińska, Katarzyna,Sata?a, Grzegorz,Jastrz?bska-Wi?sek, Magdalena,Partyka, Anna,Bojarski, Andrzej J.,Weso?owska, Anna,Kie?-Kononowicz, Katarzyna,Handzlik, Jadwiga
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Read Online
- Magnesiate Addition/Ring-Expansion Strategy to Access the 6-7-6 Tricyclic Core of Hetisine-Type C20-Diterpenoid Alkaloids
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A synthetic strategy to access the fused 6-7-6 tricyclic core of hetisine-type C20-diterpenoid alkaloids is reported. This strategy employs a Diels-Alder cycloaddition to assemble a fused bicyclic anhydride intermediate, which is elaborated to
- Pflueger, Jason J.,Morrill, Louis C.,Degruyter, Justine N.,Perea, Melecio A.,Sarpong, Richmond
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Read Online
- Preparation method of carboxylic ester compound
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The invention relates to a preparation method of a carboxylic ester compound, which comprises the following steps: reacting carboxylic acid with methanol in air under the catalysis of nitrite to obtain an ester compound, the preparation method disclosed by the invention has the advantages of rich raw material sources, cheap and easily available catalyst, mild reaction conditions, simplicity and convenience in operation and the like, a series of fatty carboxylic acids can be modified with high yield, and particularly, the traditional esterification method is generally not suitable for esterification of drug molecules. By utilizing the method, a series of known drug molecules can be modified, so that a shortcut is provided for discovering new drug molecules.
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Paragraph 0050-0051
(2021/03/30)
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- Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
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In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
- Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
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supporting information
p. 2713 - 2718
(2021/06/25)
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- N-Phenyl-1,2,3,4-tetrahydroisoquinoline: An Alternative Scaffold for the Design of 17β-Hydroxysteroid Dehydrogenase 1 Inhibitors
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17β-Hydroxysteroid dehydrogenases catalyse interconversion at the C17 position between oxidized and reduced forms of steroidal nuclear receptor ligands. The type 1 enzyme, expressed in malignant cells, catalyses reduction of the less-active estrone to estradiol, and inhibitors have therapeutic potential in estrogen-dependent diseases such as breast and ovarian cancers and in endometriosis. Synthetic decoration of the nonsteroidal N-phenyl-1,2,3,4-tetrahydroisoquinoline (THIQ) template was pursued by using Pomeranz-Fritsch-Bobbitt, Pictet-Spengler and Bischler-Napieralski approaches to explore the viability of this scaffold as a steroid mimic. Derivatives were evaluated biologically in vitro as type 1 enzyme inhibitors in a bacterial cell homogenate as source of recombinant protein. Structure-activity relationships are discussed. THIQs possessing a 6-hydroxy group, lipophilic substitutions at the 1- or 4-positions in combination with N-4′-chlorophenyl substitution were most favourable for activity. Of these, one compound had an IC50 of ca. 350 nM as a racemate, testifying to the applicability of this novel approach.
- Mottinelli, Marco,Sinreih, Ma?a,Ri?ner, Tea L.,Leese, Mathew P.,Potter, Barry V. L.
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p. 259 - 291
(2020/12/07)
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- Blue Light-Promoted N?H Insertion of Carbazoles, Pyrazoles and 1,2,3-Triazoles into Aryldiazoacetates
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Blue light irradiation of aryldiazoacetates leads to the formation of free carbenes, which can react with carbazoles, pyrazoles and 1,2,3-triazoles to afford the corresponding N?H inserted products. These reactions are performed under air and at room temperature, allowing the mild preparation of a variety of motifs found in biologically relevant targets. (Figure presented.).
- Stivanin, Mateus L.,Fernandes, Alessandra A. G.,da Silva, Amanda F.,Okada, Celso Y.,Jurberg, Igor D.
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supporting information
p. 1106 - 1111
(2020/01/25)
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- Room Temperature Coupling of Aryldiazoacetates with Boronic Acids Enhanced by Blue Light Irradiation
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A visible-light-promoted photochemical protocol is reported for the coupling of aryldiazoacetates with boronic acids. This photochemical reaction shows great enhancement compared to the same protocol performed in the absence of light. Except for a few cases, the room temperature coupling in the dark (thermal process) generally does not work. When it does, it is likely to also involve free carbenes as key intermediates. Alternatively, photochemical reactions show a broad scope, can be performed under air and tolerate a wide variety of functional groups. Reaction-evolution monitoring, DFT calculations and control experiments have been used to evaluate the main aspects of this intricate mechanistic scenario. Biologically active molecules Adiphenine, Benactyzine and Aprophen have been prepared as examples of synthetic applications.
- da Silva, Amanda F.,Afonso, Marco A. S.,Cormanich, Rodrigo A.,Jurberg, Igor D.
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supporting information
p. 5648 - 5653
(2020/04/22)
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- Photocatalytic Hydromethylation and Hydroalkylation of Olefins Enabled by Titanium Dioxide Mediated Decarboxylation
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A versatile method for the hydromethylation and hydroalkylation of alkenes at room temperature is achieved by using the photooxidative redox capacity of the valence band of anatase titanium dioxide (TiO2). Mechanistic studies support a radical-based mechanism involving the photoexcitation of TiO2 with 390 nm light in the presence of acetic acid and other carboxylic acids to generate methyl and alkyl radicals, respectively, without the need for stoichiometric base. This protocol is accepting of a broad scope of alkene and carboxylic acids, including challenging ones that produce highly reactive primary alkyl radicals and those containing functional groups that are susceptible to nucleophilic substitution such as alkyl halides. This methodology highlights the utility of using heterogeneous semiconductor photocatalysts such as TiO2 for promoting challenging organic syntheses that rely on highly reactive intermediates.
- Zhu, Qilei,Nocera, Daniel G.
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supporting information
p. 17913 - 17918
(2020/12/04)
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- Synthesis of Functionalized Indolines and Dihydrobenzofurans by Iron and Copper Catalyzed Aryl C-N and C-O Bond Formation
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A simple and effective one-pot, two-step intramolecular aryl C-N and C-O bond forming process for the preparation of a wide range of benzo-fused heterocyclic scaffolds using iron and copper catalysis is described. Activated aryl rings were subjected to a highly regioselective, iron(III) triflimide-catalyzed iodination, followed by a copper(I)-catalyzed intramolecular N-or O-arylation step leading to indolines, dihydrobenzofurans, and six-membered analogues. The general applicability and functional group tolerance of this method were exemplified by the total synthesis of the neolignan natural product, (+)-obtusafuran. DFT calculations using Fukui functions were also performed, providing a molecular orbital rationale for the highly regioselective arene iodination process.
- Henry, Martyn C.,Senn, Hans Martin,Sutherland, Andrew
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p. 346 - 364
(2019/01/08)
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- Efficient Synthesis of Spirooxindole Pyrrolones by a Rhodium(III)-Catalyzed C?H Activation/Carbene Insertion/Lossen Rearrangement Sequence
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A rhodium(III)-catalyzed domino annulation of simple olefins with diazo oxindoles to give spirooxindole pyrrolone products is described. This reaction can be formally viewed as the result of an anomalous tandem C?H activation, carbene insertion, Lossen rearrangement, and a nucleophilic addition process. The potential utility of this reaction was further demonstrated by the late-stage diversification of drug molecules.
- Ma, Biao,Wu, Peng,Wang, Xing,Wang, Zhengyu,Lin, Hai-Xia,Dai, Hui-Xiong
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supporting information
p. 13335 - 13339
(2019/08/20)
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- Meta C-H Arylation of Electron-Rich Arenes: Reversing the Conventional Site Selectivity
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Controlling site selectivity of C-H activation without using a directing group remains a significant challenge. While Pd(II) catalysts modulated by a mutually repulsive pyridine-type ligand have been shown to favor the relatively electron-rich carbon centers of arenes, reversing the selectivity to favor palladation at the relatively electron-deficient positions has not been possible. Herein we report the first catalytic system that effectively performs meta C-H arylation of a variety of alkoxy aromatics including 2,3-dihydrobenzofuran and chromane with exclusive meta site selectivity, thus reversing the conventional site selectivity governed by native electronic effects. The identification of an effective ligand and modified norbornene (NBE-CO2Me), as well as taking advantage of the statistics, are essential for achieving the exclusive meta selectivity.
- Liu, Luo-Yan,Qiao, Jennifer X.,Yeung, Kap-Sun,Ewing, William R.,Yu, Jin-Quan
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supporting information
p. 14870 - 14877
(2019/10/02)
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- A sustainable procedure toward alkyl arylacetates: Palladium-catalysed direct carbonylation of benzyl alcohols in organic carbonates
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A sustainable procedure for the synthesis of various alkyl arylacetates from benzyl alcohols has been developed. With palladium as the catalyst and organic carbonates as the green solvent and in situ activator, benzyl alcohols were carbonylated in an efficient manner without any halogen additives.
- Li, Yahui,Wang, Zechao,Wu, Xiao-Feng
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supporting information
p. 969 - 972
(2018/03/13)
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- Discovery, synthesis, and structure-activity relations of 3,4-dihydro-1H-spiro(naphthalene-2,2′-piperidin)-1-ones as potassium-competitive acid blockers
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With the aim to discover a gastric antisecretory agent more potent than the existing proton pump inhibitors, novel 3,4-dihydro-1H-spiro(naphthalene-2,2′-piperidin)-1-one derivatives, which could occupy two important lipophilic pockets (described as LP-1 and LP-2) of H+,K+-ATPase and can strongly bind to the K+-binding site, were designed based on a docking model. Among the compounds synthesized, compound 4d showed a strong H+,K+-ATPase-inhibitory activity and a high stomach concentration in rats, resulting in potent inhibitory action on histamine-stimulated gastric acid secretion in rats. Furthermore, 4d exerted significant inhibitory action on histamine-stimulated gastric-acid secretion in rats with a rapid onset and moderate duration of action after the administration. These findings may lead to a new insight into the drug design of potassium-competitive acid blockers.
- Imaeda, Toshihiro,Ono, Koji,Nakai, Kazuo,Hori, Yasunobu,Matsukawa, Jun,Takagi, Terufumi,Fujioka, Yasushi,Tarui, Naoki,Kondo, Mitsuyo,Imanishi, Akio,Inatomi, Nobuhiro,Kajino, Masahiro,Itoh, Fumio,Nishida, Haruyuki
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p. 3719 - 3735
(2017/06/13)
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- Acetylcholinesterase inhibition activity of some quinolinyl substituted triazolothiadiazole derivatives
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A series of aralkanoic acids was converted into aralkanoic acid hydrazides through their esters formation. The aralkanoic acid hydrazides upon treatment with carbon disulfide and methanolic potassium hydroxide yielded potassium dithiocarbazinate salts, which on refluxing with aqueous hydrazine hydrate yielded 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles. The target compounds, 3-aralkyl-6-(substitutedquinolinyl) [1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles, were synthesized by condensing various quinolinyl substituted carboxylic acids with 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles in phosphorus oxychloride. The structures of the newly synthesized triazolothiadiazoles were characterized by IR, 1H NMR, 13C NMR, and elemental analysis studies. The structure of one of the 5-aralkyl-4-amino-3-mercapto-1,2,4-triazoles was unambiguously deduced by single crystal X-ray diffraction analysis. All the synthesized compounds were screened for their acetylcholinesterase inhibition activities. Four of the triazolothiadiazoles exhibited excellent acetylcholinesterase inhibition activities as compared to the reference inhibitor.
- Rafiq, Muhammad,Saleem, Muhammad,Hanif, Muhammad,Abbas, Qamar,Lee, Ki Hwan,Seo, Sung-Yum
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p. 170 - 177
(2015/04/14)
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- Highly efficient and chemoselective zinc-catalyzed hydrosilylation of esters under mild conditions
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A mild and highly efficient catalytic hydrosilylation protocol for room-temperature ester reductions has been developed using diethylzinc as the catalyst. The methodology is operationally simple, displays high functional group tolerance and provides for a facile access to a broad range of different alcohols in excellent yields.
- Kovalenko, Oleksandr O.,Adolfsson, Hans
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supporting information
p. 2785 - 2788
(2015/02/05)
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- Similarities and differences in the crystal packing of methoxybenzyl and methoxyphenylethyl-1,3,4-oxadiazole-2(3H)-thiones
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This work reports the crystal and molecular structures of five 1,3,4-oxadiazol-2(3H)-thiones derived from 2, 3 and 4-methoxy substituted 2-phenylacetic acid and 2- and 4-methoxy substituted 3-phenylpropanoic acid. The methoxybenzyl-1,3,4-oxadiazol-2(3H)-thiones are V-shaped while the corresponding methoxyphenylethyl-systems are close to planar, which impacts the solid state molecular packing arrangement. For molecules 1-4, inversion related N-H...S hydrogen bonds generating R22(8) rings dominate the packing, supported by an eclectic mix of C-H...O, C-H...S, C-H...π and π...π contacts that stack the molecules into interconnected columns. In contrast, each of the two unique molecules in the asymmetric unit of 5 forms N-H...O contacts with like molecules augmented by C-H...S contacts for one molecule and C-H...O contacts for the other to generate planar layers that are interconnected though a series of π...π stacking interactions. The Royal Society of Chemistry.
- Khan, Imtiaz,Ibrar, Aliya,Simpson, Jim
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p. 164 - 174
(2014/01/06)
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- Switching pathways: Room-temperature neutral solvolysis and substitution of amides
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Stick or twist: By introducing steric hindrance at the nitrogen atom, stable linear amides bearing an electron-withdrawing α-substituent (Z=Ar, PhSO2, P(O)(OR)2, CN, or CO2R) can be induced to undergo solvolysis and substitution reactions through an elimination-addition mechanism (see picture). Key to this process is a low barrier to rotation around the amide bond and the α-substituentZ. Copyright
- Hutchby, Marc,Houlden, Chris E.,Haddow, Mairi F.,Tyler, Simon N. G.,Lloyd-Jones, Guy C.,Booker-Milburn, Kevin I.
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supporting information; experimental part
p. 548 - 551
(2012/02/04)
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- Tripeptidic BACE1 inhibitors devised by in-silico conformational structure-based design
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Previously reported pentapeptidic BACE1 inhibitors, designed using a substrate-based approach, were used as lead compounds for the further design of non-peptidic BACE1 inhibitors. Although these peptidic and non-peptidic inhibitors, with a hydroxymethylcarbonyl isostere as a substrate transition-state mimic, exhibited potent BACE1 inhibitory activities, their molecular-sizes appeared a little too big (molecular weight of >600 daltons) for developing practical anti-Alzheimer's disease drugs. To develop lower weight BACE1 inhibitors, a series of tripeptidic BACE1 inhibitors were devised using a design approach based on the conformation of a virtual inhibitor bound to the BACE1 active site, also called 'in-silico conformational structure-based design'. Although these tripeptidic BACE1 inhibitors contained some natural amino acid residues, they are expected to be useful as lead compounds for developing the next generation BACE1 inhibitors, due to their low molecular size and unique structural features compared with previously reported inhibitors.
- Hamada, Yoshio,Tagad, Harichandra D.,Nishimura, Yoshinori,Ishiura, Shoichi,Kiso, Yoshiaki
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scheme or table
p. 1130 - 1135
(2012/03/26)
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- Synthesis, urease inhibition, antioxidant and antibacterial studies of some 4-Amino-5-aryl-3H-1,2,4-triazole-3-thiones and their 3,6-Disubstituted 1,2,4-Triazolo[3,4-b]1,3,4-thiadiazole derivatives
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A new series of 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones, bearing various methoxybenzyl- and methoxyphenethyl groups, was synthesized by refluxing potassium hydrazinecarbodithioate salts in dilute aqueous solution of hydrazine hydrate. These salts were formed by the reaction of acid hydrazides and carbon disulfide in methanolic potassium hydroxide solution at 0-5 °C. 4-Amino-5-aryl-3H-1,2,4-triazole-3-thiones were condensed with different substituted aromatic acids to yield 3,6-disubstituted-1,2,4-triazolo[3,4-b]1,3, 4-thiadiazoles. The structures of the synthesized compounds were characterized by infrared (IR), 1H and 13C nuclear magnetic resonance (NMR), elemental analysis and mass spectrometric (MS) studies. All the synthesized compounds were screened for their urease inhibition, antioxidant and antibacterial activities. Some compounds showed excellent urease inhibition activity, more than the standard drug. Others exhibited potent antioxidant activity. All the compounds showed significant antibacterial activities as compared to the standard drug.
- Hanif, Muhammad,Saleem, Muhammad,Hussain, Muhammad Tahir,Rama, Nasim Hasan,Zaib, Sumera,Aslam, Muhammad Adil M.,Jones, Peter G.,Iqbal, Jamshed
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experimental part
p. 854 - 860
(2012/07/28)
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- Synthesis, urease and acetylcholine esterase inhibition activities of some 1,4-disubstituted thiosemicarbazides and their 2,5-disubstituted thiadiazoles
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A new series of 2,5-disubstituted-1,3,4-thiadiazoles 6a-i was synthesized by overnight stirring various 1,4-disubstituted thiosemicarbazides 5a-i in polyphosphoric acid followed by neutralization. The structures of newly synthesized compounds 5a-i and 6a-i were characterized by IR, 1H and 13C NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were evaluated for their urease and acetylcholine esterase inhibition activities. Thiosemicarbazides 5a-i are found to possess excellent potential for urease inhibition, more than the standard drug. Thiosemicarbazides 5a-i are more potent urease inhibitor than their cyclic analogues thiadiazoles 6a-i. Almost all of the compounds are excellent inhibitors of acetylcholine esterase. The inhibition of acetylcholine esterase of compounds 5a, 5c, 5d, 5g, 5i, 6e, 6f, 6g, and 6i is much more than that of standard drug.
- Saleem, Muhammad,Rafiq, Muhammad,Hanif, Muhammad,Rama, Nasim Hasan,Seo, Sung-Yum,Lee, Ki-Hwan
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p. 2741 - 2747
(2012/10/29)
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- Synthesis, crystal structure and b-glucuronidase inhibition activity of some new hydrazinecarboxamides and their 1,2,4-triazole derivatives
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A new series of hydrazinecarboxamides (5a-n), bearing various methoxyphenyl and methoxyphenethyl groups, was synthesized by condensation of corresponding acid hydrazides (3a-f) with methoxyphenylisocyanates (4a-c). Dehydrocyclization of hydrazinecarboxamides (5a-n) yielded corresponding methoxyphenyl and methoxyphenethyl substituted triazoles (6a-l) by refluxing in 2 N aqueous sodium hydroxide solution. All the synthesized compounds were screened for their b-glucuronidase inhibition activity. Compounds 5a, 5e, 5h, and 5l exhibited an excellent b-glucuronidase inhibitory activity as compared to the standard inhibitor. Springer Science+Business Media, LLC 2011.
- Hanif, Muhammad,Khan, Imtiaz,Rama, Nasim Hasan,Noreen, Shagufta,Choudhary, Muhammad Iqbal,Jones, Peter G.,Iqbal, Mazhar
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p. 3885 - 3896
(2013/02/23)
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- Synthesis, acetylcholinesterase and alkaline phosphatase inhibition of some new 1,2,4-triazole and 1,3,4-thiadiazole derivatives
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A new series of 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones (6as) and 2,5-disubstituted-1,3,4-thiadiazoles (7ah) was synthesized by intramolecular dehydrocyclization of various 1,4-disubstituted thiosemicarbazide derivatives (5as) by refluxing in 4N aqueous sodium hydroxide and by overnight stirring with polyphosphoric acid, respectively. The structures of these compounds were characterized by IR, 1H and 13C NMR, elemental analysis and mass spectroscopic studies. All the synthesized compounds were screened for their acetylcholinesterase and alkaline phosphatase inhibition studies. Most of the tested compounds showed promising activities, amongst them (6k) and (6q) showed excellent acetylcholinesterase inhibitory activity with IC50 0.2410.012 and 0.2600.013M, respectively, as compared with those of standard drug whereas the compound (6p), with IC50 0.0440.001M, was found to be the most potent inhibitor of alkaline phosphatase.
- Khan, Imtiaz,Hanif, Muhammad,Rama, Nasim Hasan,Hussain, Muhammad Tahir,Khan, Aftab Ahmed,Aslam, Muhammad Adil S.,Iqbal, Jamshed
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p. 1413 - 1419,7
(2020/09/02)
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- Structural assignment of 6-oxy purine derivatives through computational modeling, synthesis, x-ray diffraction, and spectroscopic analysis
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6-Oxy purine derivatives have been considered as potential therapeutic agents in various drug discovery efforts reported in the literature. However, the structural assignment of this important class of compounds has been controversial concerning the speci
- Zhao, Xinyun,Chen, Xi,Yang, Guang-Fu,Zhan, Chang-Guo
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body text
p. 6968 - 6972
(2010/09/04)
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- Total synthesis of haouamine A: the indeno-tetrahydropyridine core
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A full account of synthetic efforts toward the indeno-tetrahydropyridine core of haouamine A is presented. Initial failed strategies led to the unexpected discovery of a mild abnormal Chichibabin pyridine synthesis and provided knowledge and inspiration f
- Burns, Noah Z.,Jessing, Mikkel,Baran, Phil S.
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scheme or table
p. 6600 - 6610
(2011/02/25)
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- SUBSTITUTED BENZIMIDAZOLONE DERIVATIVES, MEDICAMENTS COMPRISING THEM AND THEIR USE
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The present invention relates to novel benzimidazolone derivatives of the general formula (I) in which the substituents R1, R2, R3, A1, A2, and B are as defined in claim 1, medicaments comprising these, and the use thereof for the prophylaxis and/or treatment of vasopressin-dependent diseases.
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Page/Page column 64
(2008/06/13)
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- Inhibitors of semicarbazide-sensitive amine oxidase (SSAO) and VAP-1 mediated adhesion useful for treatment and prevention of diseases
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Compositions and methods of using compositions for treatment of inflammatory diseases and immune disorders are provided. Allylamino compounds are disclosed which are inhibitors of semicarbazide-sensitive amine oxidase (SSAO) and/or vascular adhesion protein 1 (VAP-1). The compounds have therapeutic utility in suppressing inflammation and inflammatory responses, and in treatment of several disorders, including multiple sclerosis and stroke.
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Page/Page column 67
(2008/06/13)
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- Synthesis and structure-antifungal activity relationships of 3-aryl-5-alkyl-2,5-dihydrofuran-2-ones and their carbanalogues: Further refinement of tentative pharmacophore group
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Two series of 3-(substituted phenyl)-5-alkyl-2,5-dihydrofuran-2-ones related to a natural product, (-)incrustoporine, were synthesized and their in vitro antifungal activity evaluated. The compounds with halogen substituents on the phenyl ring exhibited selective antifungal activity against the filamentous strains of Absidia corymbifera and Aspergillus fumigatus. On the other hand, the influence of the lenghth of the alkyl chain at C(5) was marginal. The antifungal effect of the most active compound against the above strains was higher than that of ketoconazole, and close to that of amphotericin B. In order to verify the hypothesis about a possible relationship between the Michael-accepting ability of the compounds and their antifungal activity, a series of simple carbanalogues, 2-(substituted phenyl)cyclopent-2-enones, was prepared and subjected to antifungal activity assay as well.
- Pour, Milan,Spulak, Marcel,Balsanek, Vojtech,Kunes, Jiri,Kubanova, Petra,Buchta, Vladimir
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p. 2843 - 2866
(2007/10/03)
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- New and efficient method for esterification of carboxylic acids with simple primary and secondary alcohols using cerium(IV) ammonium nitrate (CAN)
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The esterification of phenylacetic acids and cis-oleic acid with primary and secondary simple alcohols, which also act as solvents using cerium(IV) ammonium nitrate (CAN) at room temperature gave phenylacetates and methyl (9Z)-octadec-9-enoate. The reactions, which occur under relatively mild conditions, afforded the desired products in good to excellent yields.
- Pan, Wen-Bin,Chang, Fang-Rong,Wei, Li-Mei,Wu, Ming-Jung,Wu, Yang-Chang
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p. 331 - 334
(2007/10/03)
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- Esterification of carboxylic acids with boron trichloride
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Treatment of carboxylic acids with boron trichloride followed by addition of alcohol provides the carboxylic ester. This esterification, following BCl3 ether or ester O-C cleavage reaction conditions, proceeds cleanly in good yields with most substrates. Cleavage of benzyl esters with boron trichloride then treating with methanol affords the methyl ester.
- Dyke, Christopher A.,Bryson, Thomas A.
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p. 3959 - 3961
(2007/10/03)
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- Substituted benzopyran analogs for the treatment of inflammation
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A class of benzopyrans, benzothiopyrans, dihydroquinolines, dihydronaphthalenes, and analogs thereof, is described for use in treating cyclooxygenase-2 mediated disorders. Compounds of particular interest are defined by Formula I'wherein X, A1, A2, A3, A4, R, R'', R1 and R2 are as described in the specification.
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- Synthesis and biological activities of the marine bryozoan alkaloids convolutamines A, C and F, and lutamides A and C
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Synthesis of convolutamines and lutamides, new 2,4,6-tribromo-3-methoxyphenethylamine alkaloids isolated from Floridian marine bryozoan Amathia convoluta, was accomplished by a sequence of reactions starting from 3-hydroxyphenethylamines. Cytotoxities of the synthetic lutamides, convolutamines and their de-O-methyl derivatives were examined using drug-sensitive and -resistant P388 as well as KB cell lines. The bioassay suggests that the 2,4,6-tribromo-3-methoxyphenethylamine is an indispensable unit for detection of the activities. Additionally, a reversal of drug resistance by those alkaloids is recognized. Copyright (C) 2000 Elsevier Science Ltd.
- Hashima, Hirofumi,Hayashi, Masahiko,Kamano, Yoshiaki,Sato, Nobuhiro
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p. 1757 - 1766
(2007/10/03)
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- Regioselectivity of the Base-Induced Ring Cleavage of 1-Oxygenated Derivatives of Cyclobutabenzene
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Oxy anions 3 generated from 1,2-dihydrocyclobutabenzen-1-ones 1 through addition of a charged nucleophile or from 1-hydroxy-1,2-dihydrocyclobutabenzenes 2 by deprotonation with base lead to stable products through distal and/or proximal cleavage of the strained four-membered ring via benzyl carbanion 4 and/or aryl carbanion 5. A systematic study of this process reveals the relative stability of the two isomeric carbanions 4 and 5 as a key factor in determining the course of the ring-cleavage reaction. While benzyl carbanions 4 can be trapped with carbon electrophiles, attempts at trapping aryl carbanions 5 with electrophiles other than H+ failed. In protic solvents, the magnesium salt of the tertiary alcohol 2 shows an increased rate of proximal cleavage as compared to its alkali salts. From this, we conclude that, in contrast to benzyl carbanions 4, free aryl carbanions 5 are of transient existence only. Proximal C,C-bond cleavage seems to occur either through protonation of 5 from a fast, reversible equilibrium 3?5 in which 3 strongly predominates, or in protic solvents possibly even through a rate-limiting protonation of 3 at the aromatic C-atom, bypassing free anion 5 altogether. Thus, additional factors other than just the relative stability of isomeric carbanions 4 and 5 are of importance in determining the regiochemistry of the base-induced C,C-bond cleavage in ketones 1 and in alcohols 2.
- Gokhale, Abha,Schiess, Peter
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p. 251 - 267
(2007/10/03)
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- The effect of an alkoxy group on the kinetic and thermodynamic acidity of benzene and toluene
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2-, 3- and 4-Methoxytoluene can be selectively metalated at an O-adjacent ortho position when butyllithium or tert-butyllithium in the presence of sodium (potassium) tert-butoxide or N,N,N',N'',N''-pentamethyldiethylenetriamine are employed as reagents. In contrast, lithium diisopropylamide or lithium 2,2,6,6-tetramethylpiperidide deprotonate the benzylic α-position of 2- and 3-methoxytoaluene exclusively and of 4-methoxytoluene preferentially. These relative reactivities can be rationalized by an interplay of transition state stabilizing and destabilizing forces (dipole matching and metal coordination vs. lone pair repulsion).
- Schlosser, Manfred,Maccaroni, Paola,Marzi, Elena
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p. 2763 - 2770
(2007/10/03)
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- Transition metal complexes in organic synthesis. Part 46: Synthesis of 5-arylmethyl-substituted tricarbonyl(1-4-η-cyclohexa-1,3-diene)iron complexes
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The reaction of tricarbonyl(η5-cyclohexadienylium) iron tetrafluoroborate 3 with the methyl arylacetate 6, the dimethyl arylmalonate 12, and the di-tert-butyl arylmalonate 14 provides regio- and stereoselectively the tricarbonyliron-complexed 5
- Knoelker, Hans-Joachim,Graf, Michael,Mangei, Ulrike
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experimental part
p. 530 - 535
(2011/10/12)
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- Enantiodivergent Synthesis of the Key Intermediate for Aphanorphine by Chemoenzymatic Process
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A short chemoenzymatic route to both enantiomers of the key intermediate (12) in the preparation of aphanorphine is described.Enzymatic hydrolysis of the prochiral malonate (8) followed by selective reduction was achieved in very high ee (>99percent).
- Hallinan, Keith O.,Honda, Toshio
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p. 12211 - 12216
(2007/10/02)
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- Esters of α-Arylalkanoic Acids from 'Masked' α-Halogenoalkyl Aryl Ketones and Silver Salts: Synthetic, Kinetic, and Mechanistic Aspects
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A method for the synthesis of alkyl esters of α-arylalkanoic acids is given based on silver-ion-assisted (AgBF4, AgOSO2CF3, AgSbF6, AgNO3) solvolysis of alkyl acetals of primary and secondary α-halogenoalkyl aryl ketones (Hal = I, Br, Cl) in an alcoholic medium (methanol, ethanol).The reaction is quite selective and alkyl esters are the only reaction products; ethers, which are possible substitution products, are not found.The importance of masking the carbonyl as the acetal is emphasised.The reaction is found to be first-order in AgBF4 and in the primary α-halogeno acetal.A three-point Hammett correlation (ρ = -3.29) between ?+ and the rate constants suggests a large cationic contribution as well as strong aryl participation in the transition state.The role payed by the oxygen of the acetal group in the specificity of the reaction is discussed in comparison with the reactivity of analogous compounds with saturated skeletons and of α-halogenoalkyl aryl ketones.
- Giordano, Claudio,Castaldi, Graziano,Casagrande, Francesco,Belli, Aldo
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p. 2575 - 2582
(2007/10/02)
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