- Microreactor-mediated benzylic bromination in concentrated solar radiation
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Sunlight-induced bromination of benzylic compounds was conducted in a capillary microreactor, resulting in mono-brominated compounds with yields of up to 94%. These reactions can be considered to be eco-friendly since they were carried out without an artificial light source or additional temperature control. In addition, up to 257.9mmol could be produced daily using cost-effective molecular bromine, which leads to potential improvement of industrial processes.
- Kim, Young Joon,Jeong, Myung Jin,Kim, Ji Eun,In, Insik,Park, Chan Pil
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- Synthesis of Novel Triazole-incorporated Isatin Derivatives as Antifungal, Antitubercular, and Antioxidant Agents and Molecular Docking Study
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A library of 1,2,3-triazoles efficiently prepared via click chemistry and evaluated for their antifungal, antitubercular, antioxidant, cytotoxicity, molecular docking and ADME prediction.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Khan, Firoz A. Kalam,Sangshetti, Jaiprakash N.,Nawale, Laxman,Arkile, Manisha,Sarkar, Dhiman,Shingate, Bapurao B.
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- An efficient and fast method for the preparation of benzylic bromides
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A mixture of triphenylphosphine and N-bromosuccinimide system is found to promote efficient conversion of benzylic alcohols into benzylic bromides under microwave irradiation conditions.
- Lee, Jong Chan,Hwang, Eui Yong
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- Difunctional chemosensor for Cu(ii) and Zn(ii) based on Schiff base modified anthryl derivative with aggregation-induced emission enhancement and piezochromic characteristics
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Three new anthryl Schiff base derivatives containing a similar molecular structure were synthesized through a simple method and their fluorescent properties were investigated in detail. Among these, compound 1 displayed an aggregation-induced emission (AIE) feature, 2 exhibited an aggregation-induced emission enhancement (AIEE) property, while 3 showed aggregation-caused quenching (ACQ) behavior. Single-crystal structure and theoretical calculation analysis show that the larger conjugation and the existence of multiple intra- and intermolecular interactions restricts the intramolecular vibration and rotation, which benefit the emission in the condensed state, while the tight dimer structure and intramolecular torsional motion induce fluorescence quenching. Moreover, compound 2 can be utilized as fluorescence on-off type sensor for Cu2+ in methanol-H2O (4/1, v/v, pH 7.2) HEPES buffer solution, as well as fluorescence off-on type sensor for Zn2+ in pure methanol solution. The 2:1 ligand-to-metal coordination pattern of the 2-Cu2+ and 2-Zn2+ were calculated through a Job's plot, and were further confirmed by X-ray crystal structures of complexes 2-CuBr2 and 2-ZnCl2. In addition, 2 also exhibits a piezofluorochromic characteristic. This journal is
- Yang, Mingdi,Zhang, Yan,Zhu, Weiju,Wang, Huizhen,Huang, Jing,Cheng, Longhuai,Zhou, Hongping,Wu, Jieying,Tian, Yupeng
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- Preparation and properties of a novel solution of hydrogen bromide (HBr) in 1,4-dioxane: An alternative reagent to HBr gas without protic solvents
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A solution of hydrogen bromide (HBr) in 1,4-dioxane was prepared and investigated for its ability to brominate alcohols, and hydrobrominate alkenes. This study revealed that the brominating ability of this HBr/1,4-dioxane solution is equal or superior to that of hydrobromic acid or HBr in acetic acid. The solution of HBr in 1,4-dioxane is robust, exhibiting no decomposition of the solvent, and retaining 97% of its original concentration, when kept at ?25 °C for 30 days. This solution is a liquid alternative to HBr gas without protic solvents.
- Nishio, Yuya,Mifune, Ryota,Sato, Taisuke,Ishikawa, Shin-ich,Matsubara, Hiroshi
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- Anti-tubercular agents. Part 8: Synthesis, antibacterial and antitubercular activity of 5-nitrofuran based 1,2,3-triazoles
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A series of 5-nitrofuran-triazole conjugates were synthesized and evaluated for their antimicrobial activity against both Gram-positive and Gram-negative bacterial strains. All the compounds exhibited promising inhibition towards Gram-positive pathogenic strains, while mild inhibitory effects were observed towards Gram-negative bacterial strains. Some of the compounds 8a, 8b, 8e, 8f, 8h are most active among the series exhibiting MIC value of 1.17 μg/ml against different bacterial strains. The bactericidal activity is found to be in accordance with the bacterial growth inhibition data. Compound 8e was found to be equipotent to the standard drug Ciprofloxacin displaying MBC value of 1.17 μg/ml against the bacterial strain Bacillus subtilis. The compounds have also demonstrated promising antibacterial activity against the resistant strain MRSA and were found to be effective inhibitors of biofilm formation. The compound 8b exhibited excellent anti-biofilm activity with IC50 value as low as 0.8 μg/ml. These conjugates were also screened for antitubercular activity against Mycobacterium tuberculosis H37Rv strain. Compound 8e showed promising antitubercular activity with MIC value of 0.25 μg/ml. Most of these compounds are less toxic to normal mammalian cells than the widely used antibacterial drug Ciprofloxacin.
- Kamal, Ahmed,Hussaini, Syed Mohammed Ali,Faazil, Shaikh,Poornachandra,Narender Reddy,Kumar, C. Ganesh,Rajput, Vikrant Singh,Rani, Chitra,Sharma, Rashmi,Khan, Inshad Ali,Jagadeesh Babu
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- Direct oxidative conversion of methylarenes into aromatic nitriles
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A variety of methylarenes were successfully converted into the corresponding aromatic nitriles in good to moderate yields by the treatment with NBS or DBDMH in the presence of a catalytic amount of AIBN or BPO, followed by the reaction with molecular iodine in aq NH3 in a one-pot procedure. The present reaction is a useful and practical transition-metal-free method for the preparation of aromatic nitriles from methylarenes.
- Tsuchiya, Daisuke,Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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- Visible-light-promoted Wohl-Ziegler functionalization of organic molecules with N-bromosuccinimide under solvent-free reaction conditions
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The visible-light-induced transformation of toluenes with N-bromosuccinimide (NBS) under solvent-free reaction conditions (SFRC) was studied. The reaction took place in spite of the very restricted molecular motion; toluenes could be regioselectively converted to benzyl bromides. Selective radical-chain reactions with NBS were carried out in liquid/liquid and in solid/solid systems; furthermore, reactions could be performed in the presence of air. The radical scavenger TEMPO (=2,2,6,6-tetramethylpiperidin-1- yloxy) completely suppressed the side-chain bromination of toluenes with NBS under SFRC. Electron-withdrawing groups decreased the reactivity of the toluenes, and the Hammett reaction constant ρ+ = -1.7 indicated involvement of polar radical intermediates with electrophilic character.
- Jereb, Marjan,Zupan, Marko,Stavber, Stojan
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- Polymeric ionic liquids: A strategy for preparation of novel polymeric materials
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A novel polymeric ionic liquid (PIL), bearing high C-N and N-N content, potentially suitable for new safe energetic materials and catalyst supports was introduced. The PIL was prepared by way of radical co-polymerisation of 1-vinyl-3-p-nitrobenzylimidazol
- Farzin, Manoochehr,Nosratzadegan, Keyvan,Azarnia, Jamshid,Ferdosi, Mohammad
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- Clay-Supported Cu(II) Catalyst: An Efficient, Heterogeneous, and Recyclable Catalyst for Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Alloxan-Derived Terminal Alkyne and Substituted Azides Using Click Chemistry
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A novel series of alloxan-derived 1,4-disubstituted 1,2,3-triazoles was synthesized in excellent yields under catalytic conditions using a click reaction strategy through 1,3-dipolar cycloaddition. Their structures have been ascertained on the basis of spectroanalytical and elemental analysis data. Synthesis of hybrid compounds with varying substitutions in the triazole ring was achieved by reaction between alloxan-derived terminal alkyne and a pertinent azide derivative in the presence of clay-Cu(II) as the catalyst in methanolic medium. Also, comparative evaluation of various catalytic systems [viz., CuI, CuSO4, CuI-zeolite, K10Ti, and clay-Cu(II)] was investigated. Of these catalytic systems, clay-Cu(II) was observed to be the best. The catalyst was recyclable for several runs without showing significant loss in its activity. The good selectivity, cost-efficiency, short reaction time, milder reaction conditions, and simple workup procedure are the added salient features of this synthetic protocol.
- Dubey, Nitin,Sharma, Pratibha,Kumar, Ashok
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- Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
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The equilibrium positions have been determined for the halogen redistribution reactions of tri-n-butyltin halides with a variety of structurally different types of alkyl halides and with acetyl halides.These have been related through the reaction ΔGo values to carbon-halogen bond dissociation energy differences.It is suggested that the trends observed in the latter may provide evidence for the existence of a small steric bond weakening effect in the order C-I > C-Br > C-Cl bonds on going from methyl to primary, secondary, and tertiary alkyl halides.On the other hand, with the 2,3-? bond containing allyl, benzyl, and propargyl halides , α-haloacetones, and haloacetonitriles, there may be some type of electronic carbon-halogen bond strengthening effect which lies in order C-I > C-Br > C-Cl.Finally, for the acetyl halides, the data are in agreement with increases in bond strengths resulting from ? contributions being in the order C-Cl > C-Br > C-I.
- Friedrich, Edwin C.,Abma, Charles B.
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- A scalable procedure for light-induced benzylic brominations in continuous flow
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A continuous-flow protocol for the bromination of benzylic compounds with N-bromosuccinimide (NBS) is presented. The radical reactions were activated with a readily available household compact fluorescent lamp (CFL) using a simple flow reactor design based on transparent fluorinated ethylene polymer (FEP) tubing. All of the reactions were carried out using acetonitrile as the solvent, thus avoiding hazardous chlorinated solvents such as CCl4. For each substrate, only 1.05 equiv of NBS was necessary to fully transform the benzylic starting material into the corresponding bromide. The general character of the procedure was demonstrated by brominating a diverse set of 19 substrates containing different functional groups. Good to excellent isolated yields were obtained in all cases. The novel flow protocol can be readily scaled to multigram quantities by operating the reactor for longer time periods (throughput 30 mmol h-1), which is not easily possible in batch photochemical reactors. The bromination protocol can also be performed with equal efficiency in a larger flow reactor utilizing a more powerful lamp. For the bromination of phenylacetone as a model, a productivity of 180 mmol h -1 for the desired bromide was achieved.
- Cantillo, David,De Frutos, Oscar,Rincon, Juan A.,Mateos, Carlos,Oliver Kappe
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- Facile conversion of alcohols into their bromides and iodides by N-bromo and N-iodosaccharins/triphenylphosphine under neutral conditions
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N-Bromo and N-iodosaccharins in the presence of triphenylphosphine convert alcohols into the corresponding bromides and iodides in good to excellent yields at room temperature under neutral conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Ebrahimzadeh, Farzaneh
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- One-pot transformation of methylarenes into aromatic aldehydes under metal-free conditions
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On the basis of studies of the transformation of benzylic bromides into the corresponding aromatic aldehydes by treatment with N-methylmorpholine N-oxide, various methylarenes were treated either with DBDMH in the presence of AIBN in acetonitrile at reflux (Method A) or with NBS in CCl4 under irradiation with a tungsten lamp at 30 °C (Method B), followed by treatment with N-methylmorpholine N-oxide to provide aromatic aldehydes in good yields. These methods could be adopted in one-pot transformations of methylarenes into aromatic aldehydes under conditions free of less toxic reagents and transition metals. Copyright
- Tabata, Masayuki,Moriyama, Katsuhiko,Togo, Hideo
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- N-bromosuccinimide: A facile reagent for the oxidation of benzylic alcohols to aldehydes
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The oxidation of benzylic alcohols to aldehydes using N-bromosuccinimide (NBS) under ambient conditions without use of a transition-metal catalyst has been described. Copyright Taylor & Francis Group, LLC.
- Adimurthy, Subbarayappa,Patoliya, Paresh U.
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- Novel, potent, selective and cellular active ABC type PTP1B inhibitors containing (methanesulfonyl-phenyl-amino)-acetic acid methyl ester phosphotyrosine mimetic
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Protein tyrosine phosphatase 1B (PTP1B) which plays an important role in the negative regulation of insulin and leptin pathway has emerged as a novel promising therapeutic target for the treatment of type 2 diabetes mellitus and obesity. Upon careful study, a series of novel scaffold and simple synthesis method inhibitors were discovered based on the analysis of X-ray crystal structures of PTP1B/inhibitor complexes and docking simulations. Among them, compound P7 exhibited high inhibitory activity (IC50 = 222 nM) with moderate selectivity (8-fold) over T-cell PTPase (TCPTP) through interacting with the A, B and C binding sites of PTP1B enzyme. Further studies on cellular activities revealed that compound P7 could enhance insulin-mediated IRβ phosphorylation and insulin-stimulated glucose uptake.
- Liu, Peihong,Du, Yongli,Song, Lianhua,Shen, Jingkang,Li, Qunyi
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- HOMOLYTIC DISPLACEMENT AT CARBON VI. SYNTHESIS OF TRICHLOROETHYLARENES FROM BENZYLCOBALOXIMES
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Benzylbis(dimethylglyoximato)pyridinecobalt(III) reacts with bromotrichloromethane at from 50 to 90 deg C in chloroform to give good yields of trichloroethylbenzene, which are higher when imidazole is present in the reaction mixture.Methyl- and polymethyl-substituted benzylbis(dimethylglyximato)pyridinecobalt(III) complexes give higher yields of the corresponding trichloroethylarenes (85-90percent), whereas 4-chlorobenzylbis(dimethylglyoximato)pyridinecobalt(III) only gives the 4-nitro-trichloroethylarene when imidazole is present during the reaciton.Similar reactions were observed with benzylcobaloximes and trichloromethanesulphonyl chloride both thermally and under irradiation by tungsten lamps through all-pyrex apparatus.The reactions are interpreted as a direct attack of the trichloromethyl radical on the α-carbon of the benzyl ligand.
- Bougeard, Peter,Gupta, B. Dass,Johnson, Michael D.
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- A novel stilbene-based organic dye with trans-cis isomer, polymorphism and aggregation-induced emission behavior
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Cis-trans isomer and polymorphism of 9-(4-(4-nitrostyryl)phenyl)-9H-carbzole (Dye 1) were obtained unexpectedly. Each isomer has two polymorphs, which was characterized by X-ray single crystal diffraction. Polymorphs T1 and T2 are trans-configuration and both crystallize in monoclinic space group P21/c. Polymorphs C1 and C2 are cis-configuration and crystallize in triclinic space group P-1 and monoclinic space group P21/c, respectively. Trans-isomer shows better stability and higher density than that of cis-isomer, but cis-isomer displays better solubility than that of trans-isomer. The molecular structures and packing arrangements of the four kinds of crystals show different features. The twisted conformation of cis-isomer effectively avoids π-π interactions and close packing. Both the trans and cis isomers show remarkable aggregation-induced emission effect in the acetonitrile/water mixture. In addition, fluorescence cell imaging experiment proves the potential application of the two isomers of dye 1.
- Xi, Wengang,Zhang, Yubin,Chen, Boyu,Gan, Xiaoping,Fang, Min,Zheng, Jun,Wu, Jieying,Tian, Yupeng,Hao, Fuying,Zhou, Hongping
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- Catalytic Bromination of Alkyl sp3C-H Bonds with KBr/Air under Visible Light
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Alkyl sp3C-H bonds of cycloalkanes and functional branch/linear alkanes have been successfully brominated with KBr using air or O2 as an oxidant at room temperature to 40 °C. The reactions are carried out in the presence of catalytic NaNO2 in 37% HCl (aq)/solvent under visible light, combining aerobic oxidations and photochemical radical processes. For various alkane substrates, CF3CH2OH, CHCl3, or CH2Cl2 is employed as an organic solvent, respectively, to enhance the efficiency of bromination.
- Zhao, Mengdi,Lu, Wenjun
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- Intermolecular interactions boost aggregation induced emission in carbazole Schiff base derivatives
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Six D-π-A model compounds (compounds 1-6) were conveniently synthesized and characterized by 1H NMR, 13C NMR, MS and single crystal X-ray diffraction. One photon absorption and emission properties were studied by using a series of UV-visible and fluorescence spectra and theoretical calculations were applied to investigate the structure-property relationships, which showed that all six compounds possessed an obvious intramolecular charge transfer process which could be attributed to their optical properties. We simultaneously investigated their fluorescence emission performance in water/acetonitrile mixtures and found that they all have outstanding aggregation induced emission properties. Scanning electron microscopy testing illustrated that orderly aggregation was the main reason for their aggregation induced emission properties. Cytotoxicity tests indicated that all these compounds had good biocompatibility for living cells, and bio-imaging studies highlighted the potential application of the six compounds in one-photon fluorescence microscopy imaging domains.
- Gan, Xiaoping,Liu, Guangjin,Chu, Mingjie,Xi, Wengang,Ren, Zili,Zhang, Xiuli,Tian, Yupeng,Zhou, Hongping
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- Environmentally benign electrophilic and radical bromination 'on water': H2O2-HBr system versus N-bromosuccinimide
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A H2O2-HBr system and N-bromosuccinimide in an aqueous medium were used as a 'green' approach to electrophilic and radical bromination. Several activated and less activated aromatic molecules, phenylsubstituted ketones and styrene were efficiently brominated 'on water' using both systems at ambient temperature and without an added metal or acid catalyst, whereas various non-activated toluenes were functionalized at the benzyl position in the presence of visible light as a radical activator. A comparison of reactivity and selectivity of both brominating systems reveals the H2O2-HBr system to be more reactive than NBS for benzyl bromination and for the bromination of ketones, while for electrophilic aromatic substitution of methoxy-substituted tetralone it was higher for NBS. Also, higher yields of brominated aromatics were observed when using H2O2-HBr 'on water'. Bromination of styrene reveals that not just the structure of the brominating reagent but the reaction conditions: amount of water, organic solvent, stirring rate and interface structure, play a key role in defining the outcome of bromination (dibromination vs bromohydroxylation). In addition, mild reaction conditions, a straightforward isolation procedure, inexpensive reagents and a lower environment impact make aqueous brominating methods a possible alternative to other reported brominating protocols.
- Podgor?ek, Ajda,Stavber, Stojan,Zupan, Marko,Iskra, Jernej
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- Efficient organic transformations mediated by ZrOCl28H 2O in Water
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Operationally simple and environmentally benign methods for some organic transformations comprising reductive coupling of sulfonyl chlorides, chemoselective deoxygenation of sulfoxides, and halogenation of alcohols mediated by ZrOCl28H2O/MX in water have been developed.
- Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Heidari, Mahdieh
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- Generation of α-imino gold carbenes through gold-catalyzed intermolecular reaction of azides with ynamides
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The generation of α-imino gold carbenes via gold-catalyzed intermolecular reaction of azides and ynamides is disclosed. This new methodology allows for highly regioselective access to valuable 2-aminoindoles and 3-amino-β-carbolines in generally good to excellent yields. A mechanistic rationale for this tandem reaction, especially for the observed high regioselectivity, is supported by DFT calculations.
- Shu, Chao,Wang, Yong-Heng,Zhou, Bo,Li, Xin-Ling,Ping, Yi-Fan,Lu, Xin,Ye, Long-Wu
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- A new diphenylphosphinite ionic liquid (IL-OPPh2) as reagent and solvent for highly selective bromination, thiocyanation or isothiocyanation of alcohols and trimethylsilyl and tetrahydropyranyl ethers
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A new diphenylphosphinite ionic liquid (IL-OPPh2) is introduced. This ionic liquid is used as both a reagent and a solvent to convert alcohols and trimethylsilyl and tetrahydropyranyl (THP) ethers into their corresponding alkyl bromides, thiocyanates or isothiocyanates in the presence of Br2 and SCN- at 80 °C. In this ionic liquid, bromination and thiocyanation of alcohols occurs highly selectively in the presence of trimethylsilyl and THP-ethers and also between different classes of alcohols. The use of this ionic liquid allows easy separation of the desired products from the phosphinate by-product.
- Iranpoor, Nasser,Firouzabadi, Habib,Azadi, Roya
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- Electrochemical method for the preparation of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes
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Electrochemical bromination of alkyl aromatic compounds by two-phase electrolysis yields the corresponding α,α-dibrominated products. The reaction has been carried out in a single-compartment electrochemical cell using aqueous sodium bromide (40-50%), containing a catalytic amount of HBr as electrolyte, and chloroform, containing an alkyl aromatic compound, as the organic phase with a Pt plate as anode at 10-15C. Two-phase electrolysis results in high yields (70-90%) of dibromomethyl, bis(bromomethyl), and bis(dibromomethyl) arenes, depending upon the charge passed.
- Kulangiappar,Karthik,Kulandainathan, M. Anbu
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- Arylmethyl radicals from arylmethoxybromodiazirines
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(Chemical Equation Presented) Photolytic decompositions of 3-arylmethoxy-3-bromodiazirines afford arylmethyl radicals by homolyses of the diazirines' excited states.
- Moss, Robert A.,Fu, Xiaolin
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- Reductive bromination of aromatic aldehydes using alkylboron dibromides
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The reductive bromination of aromatic aldehydes with isopinocampheyl boron dibromide in hexane at room temperature produces the corresponding benzyl bromides in excellent yields. (C) 2000 Elsevier Science Ltd.
- Kabalka, George W.,Wu, Zhongzhi,Ju, Yuhong
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- Benzylic Bromination-Acetoxylation of Toluenes by Bromide Ion Catalyzed Thermal Decomposition of Peroxydisulfate in Acetic Acid in the Presence of Acetate Ions
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Side-chain bromination and acetoxylation of alkylaromatics by halide ion induced decomposition of potassium peroxydisulfate in acetic acid have been studied by product analysis techniques.Catalytic amounts of lithium bromide in the presence of sodium acetate were found effective in promoting benzylic bromination, followed by conversion to the corresponding benzyl acetates by reaction with acetate.The reaction is interpreted to take place by the redox and free-radical chain mechanism involving bromine atoms (ρ = -1.38 vs. ? + for substituted toluenes).In competiti ve experiments, benzyl and 4-nitrobenzyl acetates were found lees reactive than the corresponding toluenes in acetic acid with the couple S2O82-/Br- but more reactive in carbon tetrachloride with N-bromosuccinimide.
- Citterio, Attilio,Santi, Roberto,Pagani, Anselmo
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- High selectively oxidative bromination of toluene derivatives by the H 2O2-HBr system
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An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2, Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2Cl2 at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O 2-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.
- Ju, Jie,Li, Yu Jin,Gao, Jian Rong,Jia, Jian Hong,Han, Liang,Sheng, Wei Jian,Jia, Yi Xia
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- A novel stereoselective one-pot conversion of alcohols into alkyl halides mediated by N,N′-diisopropylcarbodiimide
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Alcohols can be converted in high yields to the corresponding alkyl halides in a one-pot procedure via the corresponding O-alkylisourea; very short reaction times are possible when microwave irradiation is used.
- Crosignani, Stefano,Nadal, Brice,Li, Zhengning,Linclau, Bruno
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- Synthesis, biological evaluation and molecular docking of novel coumarin incorporated triazoles as antitubercular, antioxidant and antimicrobial agents
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A series of new coumarin-based 1,2,3-triazole derivatives were designed, synthesized and evaluated for their antitubercular activity in vitro against Mycobacterium tuberculosis H37Ra, antioxidant activity by DPPH radical scavenging assay, antimicrobial activity in vitro against three gram-positive bacteria (Staphylococcus aureus, Micrococcus luteus and Bacillus cereus) and three gram-negative bacteria (Escherichia coli, Pseudomonas fluorescens and Flavobacterium devorans as well as three fungi (Aspergillus niger, Penicillium chrysogenum and Curvularia lunata). The bioactive assay showed that some synthesized coumarin triazoles displayed comparable or even better antitubercular, antioxidant, antibacterial and antifungal efficacy in comparison with reference drugs. Furthermore, docking study has been performed against DprE1 enzyme of M. tuberculosis that showed good binding interactions. Moreover, the synthesized compounds were also analyzed for ADME properties and showed potential to build up as good oral drug candidates. Graphical Abstract: New coumarin-based 1,2,3-triazole derivatives were designed, synthesized and evaluated for their antitubercular, antioxidant, antibacterial and antifungal activity. Some of the coumarin-based triazole derivatives displayed comparable or even better efficacy in comparison with reference drugs. Molecular docking study has been performed against DprE1 enzyme of Mycobacterium tuberculosis showed good binding interactions.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Shingate, Bapurao B.,Kalam Khan, Firoz A.,Sangshetti, Jaiprakash N.,Khedkar, Vijay M.,Nawale, Laxman,Sarkar, Dhiman,Navale, Govinda R.,Shinde, Sandip S.
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- Temperature Effects on Rates of Dehalogenation of Aromatic Anion Radicals
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The temperature dependence of the unimolecular dehalogenation of radical anions of nitrobenzyl halides and haloacetophenones was measured between -7 and 70 deg C.Activation parameters range from Ea=11.2-16.9 kcal/mol and log A=12.7-17.1.Both Ea and log A increase from p- to o-nitro radicals and from chloro to bromo radicals.Unfavorable steric effects that move the halogen atom out of the aromatic plane result in lowered A factors.In general, the variation of k294 with structure depends in a complex way on the combination of Ea and log A factors, which suggests caution in the evaluation of rate constants at one temperature.The fast unimolecular dissociation of (p-NO2C6H4CH2Br)(1-). (k294=4.6*105 s-1) allows measurement of the slower bimolecular electron transfer (C6H5NO2)(1-).+p-NO2C6H4CH2Br->(p-NO2C6H4CH2Br)(1-).+C6H5NO2 (k294=1.9*106 M-1 s-1).Both the activation energy and probability factor contribute to the slow rate, possibly due to a geometry change upon the reduction of ArNO2.Extending the temperature studies to supercooled solutions shows no discontinuity of the unimolecular rate constants near the phase transition temperatures.
- Meot-Ner (Mautner), M.,Neta, P.,Norris, Robert K.,Wilson, Karen
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- Characterization of a selective inverse agonist for estrogen related receptor α as a potential agent for breast cancer
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The estrogen-related receptor α (ERRα) is an orphan nuclear receptor that plays a primary role in the regulation of cellular energy homeostasis and osteogenesis. It is reported that ERRα is widely expressed in a range of tissues and accumulating evidence has supported that the high expression of ERRα correlates with poor prognosis of various human malignancies, including breast, endometrium, colon, prostate and ovary cancers. Herein is described the discovery of a novel selective inverse agonist (HSP1604) of ERRα, but not of ERRβ and ERRγ, as determined using transient transfection luciferase reporter assay and a time-resolved fluorescence resonance energy transfer (TR-FRET) co-activator assay. HSP1604 potently inhibits ERRα transcriptional activity with IC50=1.47±0.17?μM in cell-based luciferase reporter assay and also decreases the protein level of ERRα and the mRNA levels of its downstream target genes such as pyruvate dehydrogenase kinase 4 (PDK4), pS2 and osteopontin. HSP1604 has also suppressed the proliferation of different human cancer cell lines and the migration of breast cancer cells with high expression of ERRα. Representative in vivo results show that HSP1604 suppresses the growth of human breast cancer xenograft in nude mice as doses at 30?mg/kg or 100?mg/kg administered every other day during 28-day period. HSP1604 thus has the potential both as a new agent to inhibit the growth of tumors and as a chemical probe of ERRα biology.
- Zhang, Liudi,Liu, Peihong,Chen, Haifei,Li, Qunyi,Chen, Lu,Qi, Huijie,Shi, Xiaojin,Du, Yongli
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- 1,2,3-Triazole incorporated coumarin derivatives as potential antifungal and antioxidant agents
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A series of novel ethyl-7-((1-(benzyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-oxo-2H-chromene-3-carboxylates 8a-h as potential antifungal agents were synthesized via click chemistry. The antifungal activity was evaluated against five human pathogenic fungal strains, such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger and Cryptococcus neoformans. Compound 8c, 8d, 8e and 8h were found to be equipotent against C. albicans when compared with miconazole and compound 8f was found to be two-fold more active compared with miconazole and equipotent to fluconazole against C. albicans. The coumarin-based triazole derivatives were also evaluated for antioxidant activity and compound 8a was found to be potent antioxidant when compared with standard drug. Furthermore, molecular docking study of the newly synthesized compounds was performed and results showed good binding mode in the active site of fungal C. albicans enzyme P450 cytochrome lanosterol 14α-demethylase. Moreover, the synthesized compounds were also analyzed for ADME properties and showed potential to build up as good oral drug candidates.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Khan, Firoz A. Kalam,Sangshetti, Jaiprakash N.,Shingate, Bapurao B.
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- NaIO4-mediated C-H activation of alkylbenzenes and alkanes with LiBr
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NaIO4 oxidizes lithium bromide efficiently under acidic conditions to functionalize alkylbenzenes and alkanes and produce the corresponding bromo and acetoxy derivatives in excellent yields. The protocol also demonstrates the direct conversion of cyclohexane into trans-1,2- dibromocyclohexane in moderate yield.
- Shaikh, Tanveer M.,Sudalai, Arumugam
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- Tribromoisocyanuric acid as a green reagent for benzylic bromination of alkylarenes
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The reaction of diverse alkylarenes with tribromoisocyanuric acid (0.34 mol equiv) in reflux EtOAc in the absence of any catalysts or light irradiation produced the corresponding benzyl bromides in 53-88% yield.
- De Almeida, Leonardo S.,Esteves, Pierre M.,De Mattos, Marcio C.S.
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- Thiourea-Catalyzed C?F Bond Activation: Amination of Benzylic Fluorides
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We describe the first thiourea-catalyzed C?F bond activation. The use of a thiourea catalyst and Ti(OiPr)4 as a fluoride scavenger allows the amination of benzylic fluorides to proceed in moderate to excellent yields. Preliminary results with S- and O-based nucleophiles are also presented. DFT calculations reveal the importance of hydrogen bonds between the catalyst and the fluorine atom of the substrate to lower the activation energy during the transition state.
- Houle, Camille,Savoie, Paul R.,Davies, Clotilde,Jardel, Damien,Champagne, Pier Alexandre,Bibal, Brigitte,Paquin, Jean-Fran?ois
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- Microwave-promoted, one-pot conversion of alkoxymethylated protected alcohols into their corresponding nitriles, bromides, and iodides using [bmim][InCl4] as a green catalyst
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The Lewis acid room temperature ionic liquid, [bmim][InCl4], was found to be an efficient and green catalyst for the highly chemoselective and one-pot conversion of MOM- or EOM-ethers into their corresponding nitriles, bromides, and iodides under microwave irradiation. The procedures are simple, rapid, and high yielding. The catalyst exhibited a remarkable reactivity and is reusable.
- Mirjafari, Arsalan,Mohammadpoor-Baltork, Iraj,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza
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- Aromatic aldehydes from benzylbromides via Cobalt(I) mediated benzyl radicals in the presence of aerial oxygen: A mild oxidation reaction in neutral condition
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Co(PPh3)3Cl has been shown to be a novel mediator for the conversion of benzylic bromides to aromatic aldehydes under mild conditions in the presence of acnal oxygen probably via benzylic radicals. In the absence of oxygen, the carbon-carbon coupling reactions have been utilised to attend a series of functionalised benzylic dimers.
- Goswami, Shyamaprosad,Mahapatra, Ajit Kumar
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- Synthesis and bioactivity of novel triazole incorporated benzothiazinone derivatives as antitubercular and antioxidant agent
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In search of new active molecules against Mycobacterium tuberculosis (MTB) H37Ra and M. bovis BCG, a small focused library of benzothiazinone based 1,2,3-triazoles has been efficiently prepared via click chemistry approach. Several derivatives were found to be promising inhibitors of MTB and M. bovis BCG characterized by lower MIC values (27.34-29.37 μg/mL). Among all the synthesized compounds, 6c and 6e is the most active compound against MTB and M. bovis BCG. The compounds were further tested for anti-proliferative activity against HeLa, A549 and A431 cell lines using MTT assay and showed no significant cytotoxic activity at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antioxidant activity with IC50 range = 14.14-47.11 μg/mL. Furthermore, to rationalize the observed biological activity data, the molecular docking study also been carried out against a potential target MTB DprE1, which revealed a significant correlation between the binding score and biological activity for these compounds. The results of the in vitro and in silico study suggest that the triazole incorporated benzothiazinone may possess the ideal structural requirements for further development of novel therapeutic agents.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Arkile, Manisha,Khedkar, Vijay M.,Jadhav, Nandadeep,Sarkar, Dhiman,Shingate, Bapurao B.
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- Benzylic bromination of toluene derivatives with boron tribromide
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A facile method for the benzylic bromination of toluene derivatives was developed. Various substituted toluenes were brominated with boron tribromide as bromine source in carbon tetrachloride at room temperature, affording their corresponding benzyl bromides in good yields.
- Chen, Hongbiao,Shen, Litao,Lin, Yuanbin
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- Catalyst and solvent-free bromination of toluene derivatives by HBr-H 2O2 with visible-light photocatalysis using a continuous-flow micro reactor
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The efficiency of the bromination of toluene derivatives has been improved significantly by utilising a combination of hydrogen peroxide (30%) and hydrogen bromide (40%) in a continuous-flow micro reactor. This catalyst and solvent-free reaction takes place by visible-light photocatalysis.
- Yu, Wu-Bin,Yu, Dong-Ping,Zheng, Ming-Ming,Shan, Shu-Ting,Li, Yu-Jin,Gao, Jian-Rong
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- Bromine/Bentonite Earth System, Promoter of Phenylmethanes from Toluene
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The condensation of toluene to produce o- and p-methylphenylmethanes by use of bromine with a bentonitic earth catalyst has been investigated and a mechanism is proposed based on the isolated intermediates and other related reactions.
- Salmon, Manuel,Angeles, Enrique,Miranda, Rene
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- Environmentally-friendly Wohl-Ziegler bromination: Ionic-liquid reaction and solvent-free reaction
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Environmentally-friendly Wohl-Ziegler bromination of benzylic methyl groups was successfully camed out in ionic-liquid and solvent-free systems, to produce the corresponding benzylic bromides in good to moderate yields.
- Togo, Hideo,Hirai, Takeshi
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- An efficient synthesis of benzyl bromides from aromatic aldehydes using polymethylhydrosiloxane and (bromodimethyl)sulfonium bromide or N-bromosuccinimide
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Polymethylhydrosiloxane (PMHS) in combination with (bromodimethyl)sulfonium bromide or NBS has been utilized for the first time for reductive bromination of aromatic aldehydes at room temperature to afford the corresponding benzyl bromides in excellent yields.
- Das, Biswanath,Srinivas, Yallamalla,Holla, Harish,Laxminarayana, Keetha,Narender, Ravirala
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- Synthesis of 2-alkoxy and 2-benzyloxy analogues of estradiol as anti-breast cancer agents through microtubule stabilization
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2-Methoxyestradiol (2ME2) is an investigational anticancer drug. In the present study, 2-alkoxyesters/acid and 2-benzyloxy analogues of estradiol have been synthesized as analogues of 2ME2. Three of the derivatives exhibited significant anticancer activity against human breast cancer cell lines. The best analogue of the series i.e. 24 showed stabilization of tubulin polymerisation process. It was substantiated by confocal microscopy and molecular docking studies where 24 occupied 'paclitaxel binding pocketg€ to stabilize the polymerisation process. Compound 24 significantly inhibited MDA-MB-231 cells (IC50: 7 μM) and induced arrest of cell cycle and apoptosis in MDA-MB-231 cells. In acute oral toxicity, 24 was found to be non-toxic and well tolerated in Swiss albino mice up to 1000 mg/kg dose.
- Sathish Kumar,Kumar, Amit,Singh, Jyotsna,Hasanain, Mohammad,Singh, Arjun,Fatima, Kaneez,Yadav, Dharmendra K.,Shukla, Vinay,Luqman, Suaib,Khan, Feroz,Chanda, Debabrata,Sarkar, Jayanta,Konwar, Rituraj,Dwivedi, Anila,Negi, Arvind S.
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- Photocatalytic continuous bromination method
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The invention provides a photocatalytic continuous bromination method. The method comprises the following steps: carrying out a first-stage photocatalytic continuous bromination reaction on a materialcontaining an aromatic substrate with a structural general formula I and a bromination reagent in a first continuous illumination reactor to form a first continuous system; overflowing the obtained first continuous system into a second continuous illumination reactor for a second-stage photocatalytic continuous bromination reaction to form a second continuous system; and purifying the second continuous system, wherein the structural general formula I is shown in the specification, R is selected from any one of carboxyl, ester group, NO2, CN, C1 to C8 alkyl and alkoxy, and R1 is C1 to C8 alkyl; n is 1 or 2; X is N or C, and the bromination reagent is Nbromo succinimide or dibromohydantoin. According to the bromination reagent, the selectivity of a product is improved, so the yield of the product is improved; the photocatalytic continuous bromination reaction of the two stages effectively relieves the reaction heat accumulation, and enhances the yield of the target product.
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Paragraph 0066-0067
(2021/04/03)
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- Targeted Delivery of Persulfides to the Gut: Effects on the Microbiome
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Persulfides (R?SSH) have been hypothesized as potent redox modulators and signaling compounds. Reported herein is the synthesis, characterization, and in vivo evaluation of a persulfide donor that releases N-acetyl cysteine persulfide (NAC-SSH) in response to the prokaryote-specific enzyme nitroreductase. The donor, termed NDP-NAC, decomposed in response to E. coli nitroreductase, resulting in release of NAC-SSH. NDP-NAC elicited gastroprotective effects in mice that were not observed in animals treated with control compounds incapable of persulfide release or in animals treated with Na2S. NDP-NAC induced these effects by the upregulation of beneficial small- and medium-chain fatty acids and through increasing growth of Turicibacter sanguinis, a beneficial gut bacterium. It also decreased the populations of Synergistales bacteria, opportunistic pathogens implicated in gastrointestinal infections. This study reveals the possibility of maintaining gut health or treating microbiome-related diseases by the targeted delivery of reactive sulfur species.
- Dillon, Kearsley M.,Morrison, Holly A.,Powell, Chadwick R.,Carrazzone, Ryan J.,Ringel-Scaia, Veronica M.,Winckler, Ethan W.,Council-Troche, R. McAlister,Allen, Irving C.,Matson, John B.
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supporting information
p. 6061 - 6067
(2021/02/01)
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- New 3-(1H-benzo[d]imidazol-2-yl)quinolin-2(1H)-one-based triazole derivatives: Design, synthesis, and biological evaluation as antiproliferative and apoptosis-inducing agents
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A series of 1,2,3-triazole derivatives based on the quinoline–benzimidazole hybrid scaffold was designed, synthesized, and screened against a panel of NCI-60 humanoid cancer cell lines for in vitro cytotoxicity evaluation, which revealed that compound Q6 was the most potent cytotoxic agent with excellent GI50, TGI, and LC50 values on multiple cancer cell lines. Q6 was tested further on the BT-474 breast cancer line to evaluate the mechanism of action. Preliminary screening studies based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay revealed that compound Q6 had an excellent antiproliferative effect against human breast cancer cells, BT-474, with IC50 values of 0.59 ± 0.01 μM. The detailed study based on the acridine orange/ethidium bromide staining (AO/EB) and the 4′,6-diamidino-2-phenylindole (DAPI) assay suggested that the antiproliferative activity shown was due to the induction of apoptosis on exposure to Q6. Further, DCFDA staining showed the generation of reactive oxygen species, altering the mitochondrial potential and leading to the initiation of apoptosis. This was further supported by JC-1 staining, indicating that this scaffold can contribute to the development of more potent derivatives.
- Gaikwad, Nikhil B.,Bansode, Sapana,Biradar, Shankar,Ban, Mayuri,Srinivas, Nanduri,Godugu, Chandraiah,Yaddanapudi, Venkata M.
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- The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
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Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
- Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
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supporting information
p. 5680 - 5686
(2021/08/16)
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- Preparation method of p-nitrobenzyl bromide
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The invention discloses a preparation method of p-nitrobenzyl bromide, and belongs to the technical field of organic synthesis processes. According to the preparation method, p-nitrotoluene is used asa raw material, hydrobromic acid is used as a bromine s
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Paragraph 0029-0051
(2020/06/05)
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- Thiourea-Mediated Halogenation of Alcohols
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The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
- Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
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p. 12901 - 12911
(2020/11/26)
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- A method for preparing nitro benzyl alcohol (by machine translation)
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The invention relates to a method for preparing nitro benzyl alcohol. Specifically, the preparation method to the nitro-toluene as the raw materials, the brominated, hydrolysis, refining and other steps, to make the P-nitro benzyl alcohol. In the process, without intermediate separation and purification, brominated and hydrolysis of the reaction solvent is water, and can be recycled many times, while simplifying the operation, and reduces the production cost, reducing waste water and exhaust gas emission. Preparation method of this invention, with simple operation, with little investment, environmental protection and the like, suitable for industrial production. (by machine translation)
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Paragraph 0027-0049
(2019/05/28)
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- Carbocation Catalyzed Bromination of Alkyl Arenes, a Chemoselective sp3 vs. sp2 C?H functionalization.
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The versatility of the trityl cation (TrBF4) as a highly efficient Lewis acid organocatalyst is demonstrated in a light induced benzylic brominaion of alkyl-arenes under mild conditions. The reaction was conducted at ambient temperature under common hood light (55 W fluorescent light) with catalyst loadings down to 2.0 mol% using N-bromosuccinimide (NBS) as the brominating agent. The protocol is applicable to an extensive number of substrates to give benzyl bromides in good to excellent yields. In contrast to most previously reported strategies, this protocol does not require any radical initiator or extensive heating. For electron-rich alkyl-arenes, the trityl ion catalyzed bromination could be easily switched between benzylic sp3 C?H functionalization and arene sp2 C?H functionalization by simply alternating the solvent. This chemoselective switch allows for high substrate control and easy preparation of benzyl bromides and bromoarenes, respectively. The chemoselective switch was also applied in a one-pot reaction of 1-methylnaphthalene for direct introduction of both sp3 C?Br and sp2 C?Br functionality. (Figure presented.).
- Ni, Shengjun,El Remaily, Mahmoud Abd El Aleem Ali Ali,Franzén, Johan
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supporting information
p. 4197 - 4204
(2018/09/25)
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- Visible-Light-Driven Oxidative Mono- and Dibromination of Benzylic sp 3 C-H Bonds with Potassium Bromide/Oxone at Room Temperature
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Benzylic sp 3 C-H bonds have been successfully brominated with potassium bromide by using Oxone as an oxidant in water/dichloromethane under visible light at room temperature. Toluene, ethylbenzene and other alkylbenzenes bearing an electron-withdrawing group, such as Br, Cl, COMe, CO 2 Et, CO 2 H, CN or NO 2, provide the corresponding benzylic monobromides in good to excellent yields in this reaction. Dibromides can also be produced in the presence of excess potassium bromide in a prolonged reaction time. Control of the illuminance of visible light (~500 lux) is crucial to achieving both high yield and high selectivity in these brominations. Mono- and difluorides can be conveniently prepared through nucleophilic substitutions of the benzylic bromides with potassium fluoride.
- Zhao, Mengdi,Li, Meiqi,Lu, Wenjun
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supporting information
p. 4933 - 4939
(2018/12/14)
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- Preparation method of alkane brominated material
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The invention relates to a preparation method of an alkane brominated material. The preparation method comprises the following steps: adding alkane, a bromine-containing compound or elemental bromine,a catalyst and acid into a solvent; adding the solvent into a light-transmission reaction container under air or oxygen atmosphere; sealing; performing stirring reaction under constant pressure and light illumination conditions; then analyzing a nuclear magnetic yield, and performing extraction, drying, filtration, distillation under reduced pressure and column separation to obtain the alkane brominated material. Compared with the prior art, the preparation method disclosed by the invention has the advantages that by using low-cost and safe bromic salt as a bromine source, the air as an oxidizing agent and a nitrogen-containing reagent as the catalyst, reaction is carried out under the conditions of constant temperature and constant pressure, so that energy conservation and economy are realized, and the preparation method is convenient and safe to operate and is environmentally friendly.
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Paragraph 0073-0074
(2018/09/08)
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- Dehydroxylation of alcohols for nucleophilic substitution
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The Ph3P/ICH2CH2I system-promoted dehydroxylative substitution of alcohols was achieved to construct C-O, C-N, C-S and C-X (X = Cl, Br, and I) bonds. Compared with the previous approaches such as the Appel reaction and Mitsunobu reaction, this protocol offers some practical advantages such as safe operation and a convenient amination process.
- Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
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p. 7034 - 7037
(2018/07/05)
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- Design, synthesis and evaluation of derivatives based on pyrimidine scaffold as potent Pan-Raf inhibitors to overcome resistance
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Simutaneous targeting all Raf isoforms offers the prospect of enhanced efficacy as well as reduced potential for resistance. Described herein is the discovery and characterization of a series of pyrimidine scaffold with DFG-out conformation as potent Pan-Raf inhibitors. Among them, I-41 with excellent Pan-Raf potency demonstrates inhibitory activity against BRafWTphenotypic melanoma and BRafV600Ephenotypic colon cells. The western blot results for the Erk inhibition in human melanoma SK-Mel-2?cell lines showed I-41 inhibited the proliferation of SK-Mel-2?cell lines without paradoxical activation of Erk, which supported I-41 may become a good candidate compound to overcome the resistance of melanoma against the current BRafV600Einhibitor therapy. I-41 also have a favorable pharmacokinetic profile in rat. Synthesis, SAR, lead selection, and evaluation of the key compounds studies are described.
- Wang, Lu,Zhang, Qing,Zhu, Gaoyuan,Zhang, Zhimin,Zhi, Yanle,Zhang, Li,Mao, Tianxiao,Zhou, Xiang,Chen, Yadong,Lu, Tao,Tang, Weifang
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supporting information
p. 86 - 106
(2017/03/02)
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- Rational design, synthesis, and biological evaluation of Pan-Raf inhibitors to overcome resistance
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Selective BRafV600E inhibitors with DFG-in conformation have been proven effective against a subset of melanoma. However, representative inhibitor vemurafenib rapidly acquires resistance in the BRafWT cells through a CRaf or BRafWT dependent manner. Simultaneous targeting of all subtypes of Raf proteins offers the prospect of enhanced efficacy as well as reduced potential for acquired resistance. Herein, we describe the design and characterization of a series of compounds I-01-I-22, based on a pyrimidine scaffold with DFG-out conformation as Pan-Raf inhibitors. Among them, I-15 binds to all Raf protomers with IC50 values of 12.6 nM (BRafV600E), 30.1 nM (ARaf), 19.7 nM (BRafWT) and 17.5 nM (CRaf) and demonstrates cellular activity against BRafWT phenotypic melanoma and BRafV600E phenotypic colorectal cancer cells. The western blot results for the P-Erk inhibition in human melanoma SK-Mel-2 cell line showed that I-15 inhibited the proliferation of the SK-Mel-2 cell line at concentrations as low as 400 nM, without paradoxical activation of Erk as vemurafenib, which supported that I-15 may become a good candidate compound to overcome the resistance of melanoma induced by vemurafenib. I-15 also has a favorable pharmacokinetic profile in rats. Rational design, synthesis, SAR, lead selection and evaluation of the key compounds studied are described.
- Wang, Lu,Zhu, Gaoyuan,Zhang, Qing,Duan, Chunqi,Zhang, Yanmin,Zhang, Zhimin,Zhou, Yujun,Lu, Tao,Tang, Weifang
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supporting information
p. 3455 - 3465
(2017/04/26)
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- Method for preparing benzyl bromide
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The invention provides a method for preparing benzyl bromide. The method comprises the following steps: by taking bromine released from a redox reaction between bromates and negative bromide ions in the presence of an acid as a bromine source in an organic solvent, carrying out a benzyl radical substitution reaction with a methylbenzene compound shown as a formula I under initiation of an initiator, thereby obtaining a corresponding benzyl bromide compound shown a formula II, wherein in the formula II, m represents the number of Br and is equal to 1 or 2; when m is equal to 1, the formula II shows a benzyl monobromo compound; and when m is equal to 2, the formula II shows a benzyl dibromo compound. The reaction is carried out in an organic solvent, the initiator is combined and used, the radical substitution reaction is high in selectivity and wide in substrate application range, the substituent group replacing methylbenzene may be an electron-withdrawing group or an electron-donating group and can give extremely high yield on strong electron-donating groups (such as methoxy group). Moreover, the method disclosed by the invention is also applicable to preparation of benzyl dibromo compounds, and the product yield is high.
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Paragraph 0052-0054
(2017/10/05)
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- Novel sulfonamide compound, preparation method, and use of novel sulfonamide compound as protein tyrosine phosphatase 1B inhibitor
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The invention relates to a novel sulfonamide compound in a structure of a general formula I as shown in the specification, or pharmaceutically acceptable salt and a preparation method of the novel sulfonamide compound, and further relates to a drug composition containing the compound as shown as the general formula I or the pharmaceutically acceptable salt of the compound, and a use of the compound or the pharmaceutically acceptable salt for preparing a drug for preventing and/or treating symptoms or diseases such as hyperglycemia and diabetes mellitus type 2 since the compound as shown as the general formula I or the pharmaceutically acceptable salt of the compound has activity of inhibiting a protein tyrosine phosphatase 1B (PTP 1B).
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Paragraph 0018
(2017/12/29)
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- A capable of detecting the live cell mitochondria of nickel ion in high selective fluorescent probe and its preparation method (by machine translation)
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A capable of detecting the live cell mitochondria of nickel ion in high selective fluorescent probe and its preparation method, the probe is containing pyridine base three-aniline [...] derivatives, in the preparation method, triphenylamine as the starting material, process for preparing the intermediate first I 4 - (N, N - diphenyl amino) benzaldehyde and intermediate [...] II P-nitro-toluene, and then the intermediate 1 and II preparation 4 - vinyl triphenylamine intermediate to the nitrobenzene, then in Pd/C, reduced under the action of the hydrazine hydrate obtained 4 - P vinyl tri-aniline, then with 2 - pyridobenzodiazepinones formaldehyde through condensation reaction to obtain the Schiff base, Schiff base in under the action of the sodium borohydride reduction to obtain the target product. The probe in the 425 nm the left and the right with good single-photon fluorescent nature. HepG2 cells after dyeing is the target product, can clearly observe the organic material to the HepG2 cells in the cytoplasm of mitochondrial has high imaging capability, and can reversibly detecting mitochondria in the nickel ion. The probe for organic dye design, preparation and life science research is of great significance. (by machine translation)
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Paragraph 0040-0041
(2017/10/13)
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- Inhibitors to Overcome Secondary Mutations in the Stem Cell Factor Receptor KIT
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In modern cancer therapy, the use of small organic molecules against receptor tyrosine kinases (RTKs) has been shown to be a valuable strategy. The association of cancer cells with dysregulated signaling pathways linked to RTKs represents a key element in
- Kaitsiotou, Helena,Keul, Marina,Hardick, Julia,Mühlenberg, Thomas,Ketzer, Julia,Ehrt, Christiane,Krüll, Jasmin,Medda, Federico,Koch, Oliver,Giordanetto, Fabrizio,Bauer, Sebastian,Rauh, Daniel
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p. 8801 - 8815
(2017/11/15)
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- Stability, Kinetic, and Mechanistic Investigation of 1,8-Self-Immolative Cinnamyl Ether Spacers for Controlled Release of Phenols and Generation of Resonance and Inductively Stabilized Methides
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Three cinnamyl ether spacers (non-methyl, α-methyl, and γ-methyl) for caging of phenols have been synthesized and are physiologically stable. When triggered, the γ-methyl spacer releases phenols (pKa 7.8 and 9.8) with a t1/2 a 7.8) with a t1/2 = 27 and 54 min. For the γ-methyl spacer, the results suggest the presence of a resonance and inductively stabilized aza-cinnamyl methide.
- Matikonda, Siddharth S.,Fairhall, Jessica M.,Tyndall, Joel D. A.,Hook, Sarah,Gamble, Allan B.
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supporting information
p. 528 - 531
(2017/02/10)
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- Photoluminescent discotic liquid crystals derived from tris(N-salicylideneaniline) and stilbene conjugates: Structure-property correlations
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Luminescent discotic liquid crystals based on tris(N-salicylideneaniline)s [TSANs] bearing trans-stilbene fluorophores have been synthesized. Their mesomorphic and photophysical properties were studied. These TSANs existing in the form of C3h and Cs geometrical isomers of the keto-enamine tautomer self-assemble to form the columnar phase and exhibit fluorescence both in solution and mesophase states. These columnar mesophases also exhibit frozen (glassy) columnar phase, which ensures preserved fluorescence intensity, defect free alignment and simultaneous restriction on the motion of ionic impurities. These features make them promising candidates for the use in organic light emitting diodes, particularly as emissive layers. This study also led to an understanding about the dependence of their mesomorphism (mesophase type, stability and thermal range) and photophysical features on the number and pattern of their peripheral substitution, in comparison to the analogous columnar liquid crystalline TSANs reported earlier.
- Achalkumar, Ammathnadu S.,Veerabhadraswamy,Hiremath, Uma S.,Rao, Doddamane S. Shankar,Prasad, Subbarao Krishna,Yelamaggad, Channabasaveshwar V.
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p. 291 - 305
(2016/05/24)
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- Design, synthesis and biological evaluation of coumarin derivatives as novel acetylcholinesterase inhibitors that attenuate H2O2-induced apoptosis in SH-SY5Y cells
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A novel series of coumarin derivatives were designed, synthesized and investigated for inhibition of cholinesterase, including acetyl cholinesterase (AChE) and butyrylcholinesterase (BuChE). This biological study showed that these compounds containing piperazine ring had significant inhibition activities on AChE rather than BuChE. Further study suggested that 9x, as one of this kind of structure derivative, showed the strongest inhibition activity on AChE with an IC50 value of 34?nM. Moreover, molecular docking, flow cytometry (FCM), and western blot assay suggested that 9x could induce cytoprotective autophagy to attenuate H2O2-induced cell death in human neuroblastoma SH-SY5Y cells. These findings highlight a new approach for the development of a novel potential neuroprotective compound targeting AChE with autophagy-inducing activity in future Alzheimer's disease (AD) therapy.
- Yao, Dahong,Wang, Jing,Wang, Guan,Jiang, Yingnan,Shang, Lei,Zhao, Yuqian,Huang, Jian,Yang, Shilin,Wang, Jinhui,Yu, Yamei
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p. 112 - 123
(2016/08/01)
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- An efficient and selective method for the iodination and bromination of alcohols under mild conditions
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A straightforward and effective procedure for the conversion of a variety of alcohols into the corresponding alkyl iodides and bromides is described using KX/P2O5 (X = I, Br). The reactions were easily carried out in acetonitrile under mild conditions. Using this method, the selective conversion of benzylic alcohols in the presence of aliphatic alcohols was achieved.
- Khazdooz, Leila,Zarei, Amin,Aghaei, Hamidreza,Azizi, Ghobad,Gheisari, Mohammad Mehdi
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p. 168 - 171
(2015/12/30)
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- 1,2,3-Triazole tethered acetophenones: Synthesis, bioevaluation and molecular docking study
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A small focused library of eighteen new 1,2,3-triazole tethered acetophenones has been efficiently prepared via click chemistry approach and evaluated for their antifungal and antioxidant activity. The antifungal activity was evaluated against five human pathogenic fungal strains: Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger, and Cryptococcus neoformans. Among the synthesized compounds, 9c, 9i, and 9p found to be more potent antifungal agents that the reference standard. These 1,2,3-triazole based derivatives were also evaluated for antioxidant activity, and compound 9h was found to be the most potent antioxidant as compared to the standard drug. Furthermore, molecular docking study of the newly synthesized compounds was performed and results showed good binding mode in the active site of fungal C. albicans enzyme P450 cytochrome lanosterol 14α-demethylase. Moreover, the synthesized compounds were also analyzed for ADME properties and showed potential as good oral drug candidates.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Khedkar, Vijay M.,Jha, Prakash C.,Khan, Firoz A. Kalam,Sangshetti, Jaiprakash N.,Shingate, Bapurao B.
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p. 1058 - 1063
(2016/07/29)
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- Synthesis and Biological Evaluation of 1,2,3-triazole tethered Pyrazoline and Chalcone Derivatives
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A series of pyrazoline derivatives and corresponding chalcone intermediates with substituents same as combretastatin-A4(CA-4) conjugated with triazole nucleus has been synthesized and evaluated for their anticancer potential. Sulphorhodamine B(SRB) assay indicated compound 12c to be the most active compound from the series with GI50 value of 6.7 μm against the human liver carcinoma cell line HepG2. Interestingly, the intermediate 11c exhibited more promising cytotoxicity demonstrating GI50 value of 1.3 μm against the prostate cancer cell line DU145. Compounds 11c and 12c caused accumulation of cells in G2/M phase and inhibited tubulin polymerization. Furthermore, these compounds reduce the mitochondrial membrane potential and activate caspases 3 and 9, thereby indicating their ability to trigger apoptosis.
- Hussaini, Syed Mohammed Ali,Yedla, Poornachandra,Babu, Korrapati Suresh,Shaik, Thokhir B.,Chityal, Ganesh Kumar,Kamal, Ahmed
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- Design, synthesis, and biological evaluation of benzoselenazole-stilbene hybrids as multi-target-directed anti-cancer agents
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To identify novel multi-target-directed drug candidates for the treatment of cancer, a series of benzoselenazole-stilbene hybrids were synthesised by combining the pharmacophores of resveratrol and ebselen. The biological assay indicated that all of the h
- Yan, Jun,Guo, Yueyan,Wang, Yali,Mao, Fei,Huang, Ling,Li, Xingshu
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p. 220 - 229
(2015/03/31)
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- 1,2,3-Triazole derivatives as antitubercular agents: synthesis, biological evaluation and molecular docking study
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Searching for new active molecules against Mycobacterium tuberculosis (MTB) H37Ra, a small focused library of 1,2,3-triazoles has been efficiently prepared via a click chemistry approach. The newly synthesized compounds were tested against drug-sensitive MTB. Several derivatives were found to be promising inhibitors of MTB characterized by lower MIC values (5.8-29.9 μg mL-1). Among all the synthesized 31 compounds, 15e was the most active compound against MTB. Based on the results from the anti-tubercular activity, SAR for the synthesized series has been developed. The active compounds from the anti-tubercular study were further tested for anti-proliferative activity against THP-1, A549 and PANC-1 cell lines using MTT assay and showed no significant cytotoxic activity against these three cell lines except THP-1 at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antioxidant activities with an IC50 range of 10.1-37.3 μg mL-1. The molecular docking study of the synthesized compounds was performed against the DprE1 enzyme of MTB to understand the binding interactions. Moreover, the synthesized compounds were also analysed for ADME properties and all the experimental results promote us to consider this series as a starting point for the development of novel and more potent anti-tubercular agents in the future.
- Shaikh, Mubarak H.,Subhedar, Dnyaneshwar D.,Nawale, Laxman,Sarkar, Dhiman,Kalam Khan, Firoz A.,Sangshetti, Jaiprakash N.,Shingate, Bapurao B.
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supporting information
p. 1104 - 1116
(2015/06/25)
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- BETA-SUBSTITUTED BETA-AMINO ACIDS AND ANALOGS AS CHEMOTHERAPEUTIC AGENTS
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β-Substituted β-amino acids, β-substituted β-amino acid derivatives, and β-substituted β-amino acid analogs and (bio)isosteres and their use as chemotherapeutic agents are disclosed. The β-substituted β-amino acid derivatives and β-substituted β-amino acid analogs and (bio)isosteres are selective LAT1/4F2hc substrates and exhibit rapid uptake and retention in tumors expressing the LAT1/4F2hc transporter. Methods of synthesizing the β-substituted β-amino acid derivatives and β-substituted β-amino acid analogs and methods of using the compounds for treating cancer are also disclosed. The β-substituted β-amino acid derivatives and β-substituted β-amino acid analogs exhibit selective uptake in tumor cells expressing the LAT1/4F2hc transporter and accumulate in cancerous cells when administered to a subject in vivo. The β-substituted β-amino acid derivatives and β-substituted β-amino acid analogs and (bio)isosteres exhibit cytotoxicity toward several tumor types.
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Paragraph 0544; 0601
(2015/09/22)
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- Preparation of carbazole and dibenzofuran derivatives by selective bromination on aromatic rings or benzylic groups with N-bromosuccinimide
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N-Bromosuccinimide (NBS), a bromine source, has been used to study the bromination of toluidine and cresols systematically to clarify the underlying mechanism and the orientation effect. It has been found that bromination of toluidine and cresols which possess electron-donating NH2/OH with NBS gives electrophilic aromatic substitution products quickly instead of the desired benzylic bromination products. In contrast, when the electronic effect of the substituted groups is reversed, only the benzylic bromination products are gained. Based on this methodology, several potential AChE inhibitors, such as 2-methoxy-5-(benzylamino)methyl-dibenzofuran, 3-bromo-2-methoxy-5-methyl-9H- carbazole, 3,6-dibromo-2-methoxy-5-methyl-9H-carbazole, and 5-(bromomethyl)-2- methoxy-9H-(phenylsulfonyl)-carbazole have been synthesized.
- Fang, Lei,Zhang, Haun,Fang, Xubin,Gou, Shaohua,Cheng, Lin
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p. 635 - 641
(2014/06/23)
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- Nuclear versus side-chain bromination of 4-methoxy toluene by an electrochemical method
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GRAPHICAL ABSTRACT The electrochemical bromination of 4-methoxy toluene by two-phase electrolysis yields 3-bromo 4-methoxy toluene at first, which subsequently undergoes side-chain bromination to give 3-bromo 4-methoxy benzyl bromide as a final product in 86% yield. The two-phase electrolysis consists of 25-50% NaBr as aqueous electrolyte and CHCl3 containing aromatic compound as organic phase. The reaction temperature is maintained at 10-25 °C. The probable orientation of bromine atom in an alkyl aromatic compound (nuclear versus side chain) is explained from the experimental result.
- Kulangiappar,Anbukulandainathan,Raju
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p. 2494 - 2502
(2014/08/05)
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- Friedel-crafts reaction of benzyl fluorides: Selective activation of C-f bonds as enabled by hydrogen bonding
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A Friedel-Crafts benzylation of arenes with benzyl fluorides has been developed. The reaction produces 1,1-diaryl alkanes in good yield under mild conditions without the need for a transition metal or a strong Lewis acid. A mechanism involving activation of the C-F bond through hydrogen bonding is proposed. This mode of activation enables the selective reaction of benzylic C-F bonds in the presence of other benzylic leaving groups.
- Champagne, Pier Alexandre,Benhassine, Yasmine,Desroches, Justine,Paquin, Jean-Franois
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supporting information
p. 13835 - 13839
(2015/02/05)
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- Aromatic cation activation: Nucleophilic substitution of alcohols and carboxylic acids
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A new method for the nucleophilic substitution of alcohols and carboxylic acids using aromatic tropylium cation activation has been developed. This article reports the use of chloro tropylium chloride for the rapid generation of alkyl halides and acyl chlorides under very mild reaction conditions. It demonstrates, for the first time, the synthetic potential of tropylium cations in promoting chemical transformations.
- Nguyen, Thanh V.,Bekensir, Alp
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supporting information
p. 1720 - 1723
(2014/04/17)
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