- Differential antiproliferative activity of new benzimidazole-4,7-diones
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Ten benzimidazole-4,7-diones were synthesized and tested in vitro on two tumor cell lines. Several compounds showed a significant antiproliferative activity on K562 cells, although to a different extent, whereas compound 1i showed a highly significant activity on SW620 cells, comparable to that of doxorubicin. Both the substituents in the quinone ring and the position of the nitrogen atom in the pyridine moiety play a crucial role for the biological activity.
- Garuti, Laura,Roberti, Marinella,Pizzirani, Daniela,Pession, Annalisa,Leoncini, Emanuela,Cenci, Valentina,Hrelia, Silvana
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Read Online
- Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure
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Flavinium salts are frequently used in organocatalysis but their application in photoredox catalysis has not been systematically investigated to date. We synthesized a series of 5-ethyl-1,3-dimethylalloxazinium salts with different substituents in the positions 7 and 8 and investigated their application in light-dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet-born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8-dimethoxy derivative is a superior catalyst with a sufficiently high oxidation power (E=2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds such as all-trans dimethyl 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate can be converted, whose opening requires a high activation energy due to a missing pre-activation caused by bulky adjacent substituents in cis-position.
- Hartman, Tomá?,Reisnerová, Martina,Chudoba, Josef,Svobodová, Eva,Archipowa, Nataliya,Kutta, Roger Jan,Cibulka, Radek
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p. 373 - 386
(2021/02/01)
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- Novel cathepsin K inhibitors block osteoclasts in vitro and increase spinal bone density in zebrafish
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Cathepsin K (Cat K) is a predominant cysteine protease and highly potent collagenase expressed in osteoclasts. Cat K inhibitors are anti-resorptive agents to treat osteoporosis. A novel scaffold of cathepsin K inhibitors, exemplified by lead compound 1x, was used as the template for designing and synthesizing a total of 61 derivatives that have not been reported before. An exploratory structure-activity relationship analysis identified the potent Cat K inhibitor A22, which displayed an IC50 value of 0.44 μM against Cat K. A22 was very specific for Cat K and caused a significantly higher in vitro inhibition of the enzyme as compared to that of lead compound 1x. A surface plasmon resonance analysis confirmed in vitro binding of A22 to Cat K. Molecular docking studies indicated several favourable interaction sites for A22 within the active pocket of Cat K. Furthermore, A22 also blocked active osteoclasts in vitro and increased spinal bone density in zebrafish, in which it showed an activity that was higher than that of the marketed therapeutic bone metabolizer etidronate disodium. A22 represents a very promising lead compound for the development of novel antiresorptive agents functioning as orthosteric inhibitors of Cat K.
- Xue, Si-Tu,Wang, Ya-Li,Han, Xiao-Wan,Yi, Hong,Jiang, Wei,Si, Shu-Yi,Guo, Hui-Fang,Li, Zhuo-Rong
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p. 8600 - 8607
(2019/03/21)
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- Pd-Pt/modified GO as an efficient and selective heterogeneous catalyst for the reduction of nitroaromatic compounds to amino aromatic compounds by the hydrogen source
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In this work, different nitroaromatic compounds were successfully reduced to their corresponding aromatic amines with excellent conversion and selectivity in methanol at 50?°C by using Pd-Pt nanoparticles immobilized on the modified grapheme oxide (m-GO) and hydrogen as the reducing source. The catalytic efficiency of Pd and Pd-Pt loading on the modified GO was investigated for the reduction of various nitroaromatic compounds, and the Pd-Pt/m-GO system demonstrated the highest conversion and selectivity. The catalyst was characterized by different techniques including FT-IR, Raman, UV–Vis, XRD, BET, XPS, FESEM, EDS, and TEM. The metal nanoparticles with the size of less than 10?nm were uniformly distributed on the m-GO. The catalyst could be reused at least five times without losing activity, showing the stability of the catalyst structure. Finally, the efficiency of the prepared catalyst was compared with Pd-Pt/AC, and Pd-Pt/GO catalysts.
- Salahshournia, Hossein,Ghiaci, Mehran
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- Green synthesis and: In situ immobilization of gold nanoparticles and their application for the reduction of p -nitrophenol in continuous-flow mode
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A green and facile method has been developed for the preparation of in situ immobilized gold nanoparticles (AuNPs) using agarose as a reducing and stabilizing agent. The size of the synthesized AuNPs ranges between 10 and 100 nm, and their average size can be controlled by the concentrations of the agarose and gold salt. The agarose matrix as a mild and green reaction medium can provide a good dispersion environment for forming AuNPs, and the hydrogel can be well homogenized with polyacrylic macroporous microbeads as well, which can adsorb and stabilize the particles leading to the simultaneous synthesis and immobilization of AuNPs avoiding harmful inorganic compounds or organic solvents. The supported gold nanocatalyst was successfully applied as a catalyst in packed bed reactors for efficient NaBH4-mediated reduction of p-nitrophenol in continuous-flow mode.
- Szcs, Rózsa,Balogh-Weiser, Diána,Sánta-Bell, Evelin,Tóth-Szeles, Eszter,Varga, Tamás,Kónya, Zoltán,Poppe, László,Lagzi, István
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p. 9193 - 9197
(2019/03/28)
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- Metal-free Reduction of Nitro Aromatics to Amines with B 2 (OH) 4 /H 2 O
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A metal-free reduction of nitro aromatics mediated by diboronic acid with water as both the hydrogen donor and solvent under mild conditions has been developed. A series of aromatic amines were obtained with good functional group tolerance and in good yields.
- Chen, Danyi,Zhou, Yanmei,Zhou, Haifeng,Liu, Sensheng,Liu, Qixing,Zhang, Kaili,Uozumi, Yasuhiro
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supporting information
p. 1765 - 1768
(2018/06/26)
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- A capping agent dissolution method for the synthesis of metal nanosponges and their catalytic activity towards nitroarene reduction under mild conditions
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We report a general strategy for the synthesis of metal nanosponges (M = Ag, Au, Pt, Pd, and Cu) using a capping agent dissolution method where addition of water to the M@BNHx nanocomposite affords the metal nanosponges. The B-H bond of the BNHx polymer gets hydrolysed upon addition of water and produces hydrogen gas bubbles which act as dynamic templates leading to the formation of nanosponges. The rate of B-H bond hydrolysis has a direct impact on the final nanostructure of the materials. The metal nanosponges were characterized using powder XRD, electron microscopy, XPS, and BET surface area analyzer techniques. The porous structure of these nanosponges offers a large number of accessible surface sites for catalytic reactions. The catalytic activity of these metal nanosponges has been demonstrated for the reduction of 4-nitrophenol where palladium exhibits the highest catalytic activity (k = 0.314 min?1). The catalytic activity of palladium nanosponge was verified for the tandem dehydrogenation of ammonia borane and the hydrogenation of nitroarenes to arylamines in methanol at room temperature. The reduction of various substituted nitroarenes was proven to be functional group tolerant except for a few halogenated nitroarenes (X = Br and I) and >99% conversion was noted within 30-60 min with high turnover frequencies (TOF) at low catalyst loading (0.1 mol%). The catalyst could be easily separated out from the reaction mixture via centrifugation and was recyclable over several cycles, retaining its porous structure.
- Ghosh, Sourav,Jagirdar, Balaji R.
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p. 17401 - 17411
(2019/01/03)
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- Water as a hydrogen source in palladium-catalyzed reduction and reductive amination of nitroarenes mediated by diboronic acid
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An unprecedented palladium-catalyzed chemoselective reduction and reductive amination of nitroarenes with water as a hydrogen source mediated by diboronic acid have been discovered. A series of aryl amines containing various reducible functional groups were obtained in good to excellent yields.
- Zhou, Yanmei,Zhou, Haifeng,Liu, Sensheng,Pi, Danwei,Shen, Guanshuo
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p. 3898 - 3904
(2017/06/13)
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- A containing methyl pyrazine structure of the hydrazone compound and its preparation method and application (by machine translation)
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The invention discloses a containing methyl pyrazine structure of the hydrazone compound and its preparation method and application. It to 5 - methyl O-nitroaniline and hydrazine hydrate to obtain compound 1; compound 1 with the role of the BMF prepared compound 2; compound 2 by the reaction of the compound with phosphorus oxychloride 3; compound 3 is obtained by the reaction with hydrazine hydrate compound 4; compound 4 with the substituted aldehyde compound by the reaction of the compound (I). Its raw material is simple and easy, simple preparation method, after treatment is convenient, high product yield, but the compound is has herbicidal activity, in particular against bentgrasses, has certain herbicidal effect, to provide the basis for a new pesticide research. (by machine translation)
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Paragraph 0027
(2017/06/02)
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- Potent, Selective, and Cell Active Protein Arginine Methyltransferase 5 (PRMT5) Inhibitor Developed by Structure-Based Virtual Screening and Hit Optimization
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PRMT5 plays important roles in diverse cellular processes and is upregulated in several human malignancies. Besides, PRMT5 has been validated as an anticancer target in mantle cell lymphoma. In this study, we found a potent and selective PRMT5 inhibitor by performing structure-based virtual screening and hit optimization. The identified compound 17 (IC50 = 0.33 μM) exhibited a broad selectivity against a panel of other methyltransferases. The direct binding of 17 to PRMT5 was validated by surface plasmon resonance experiments, with a Kd of 0.987 μM. Kinetic experiments indicated that 17 was a SAM competitive inhibitor other than the substrate. In addition, 17 showed selective antiproliferative effects against MV4-11 cells, and further studies indicated that the mechanism of cellular antitumor activity was due to the inhibition of PRMT5 mediated SmD3 methylation. 17 may represent a promising lead compound to understand more about PRMT5 and potentially assist the development of treatments for leukemia indications.
- Mao, Ruifeng,Shao, Jingwei,Zhu, Kongkai,Zhang, Yuanyuan,Ding, Hong,Zhang, Chenhua,Shi, Zhe,Jiang, Hualiang,Sun, Dequn,Duan, Wenhu,Luo, Cheng
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p. 6289 - 6304
(2017/08/02)
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- Preparation method of 2-substituted benzimidazole derivative
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The invention discloses a preparation method of a 2-substituted benzimidazole derivative 1-(5-methyl-1H-benzo[d]imidazole-2-yl) piperidine-4-carboxylic acid. 5-methyl-2-nitroaniline is taken as an initial raw material and subjected to reduction, ring closure, chlorination and a nucleophilic reaction, and a target product is obtained. The compound is an important medical intermediate.
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Paragraph 0020; 0021; 0022
(2018/04/01)
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- Synthesis method of 3,4-diaminotoluene
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The invention relates to a synthesis method of 3,4-diaminotoluene. The synthesis method is characterized in that hydrogenation reduction reaction is performed by taking o-nitro-p-toluidine as a raw material under the action of a catalyst and an alcohol solvent to obtain 3,4-diaminotoluene, wherein the weight ratio of the solvent to o-nitro-p-toluidine is (1.5-3):1; and in the hydrogenation reduction reaction, the temperature is 65-85 DEG C and the pressure is 1.0-4.0 MPa. According to the synthesis method, o-nitro-p-toluidine is used as the raw material, a hydrogenation reduction process is adopted, the synthesis route is short, the product purity is high (99.5%) and the yield is high (96%-97%). Compared with the existing sodium sulfide reduction process and the ferrous powder reduction process, the synthesis method is less in reaction step, short in synthesis route, small in wastewater quantity (0.3 ton of wastewater is generated by the products per ton), high in product purity (99.5%) and stable in quality, obviously reduces the cost of the raw material and satisfies the demands of an anti-rusting agent and a corrosion inhibitor of high-quality and high-grade organic pigment disperse fluorescent yellow and synthesis metals (such as silver, copper, lead, nickel and zinc).
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Paragraph 0015; 0016; 0017; 0018; 0019; 0020
(2017/08/02)
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- An easily accessible and recyclable copper nanoparticle catalyst for the solvent-free synthesis of dipyrromethanes and aromatic amines
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A facile method to prepare a reusable copper nanocatalyst is reported. Transmission electron microscopy shows that the CuNPs are spherical in nature and reside in the nanoscopic template of the capping agent, guar gum. Powder X-ray diffraction studies confirm the crystalline nature of the CuNPs. The catalytic efficiency and recyclability of the synthesized CuNPs were demonstrated through the synthesis of dipyrromethanes (DPMs) and aromatic amines. Various DPMs are obtained in very good yields under solvent-free conditions and nitroarenes are converted to the corresponding amino compounds within 10 min, as evidenced by the kinetic study.
- Megarajan, Sengan,Ayaz Ahmed, Khan Behlol,Rajmohan, Rajamani,Vairaprakash, Pothiappan,Anbazhagan, Veerappan
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p. 103065 - 103071
(2016/11/13)
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- A containing methyl pyrazine structure of hydrazone compounds as fungicides (by machine translation)
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The invention discloses a containing methyl pyrazine structure of hydrazone compounds as fungicides. It to 4 - methyl O-nitroaniline and hydrazine hydrate to obtain compound 1; compound 1 with the role of the BMF prepared compound 2; compound 2 by the reaction of the compound with phosphorus oxychloride 3; compound 3 is obtained by the reaction with hydrazine hydrate compound 4; compound 4 with the substituted aldehyde compound by the reaction of the compound (I). Its raw material is simple and easy, simple preparation method, after treatment is convenient, high product yield, but the compound as having anti-fungal activity, in particular against anthrax sharp spore, strawberry anthrax bacteria and Fructus Lycii (wolfberry fruit) anthrax has good sterilization effect, to provide the basis for a new pesticide research. (by machine translation)
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Paragraph 0015; 0029
(2017/06/02)
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- Carbon nitride supported palladium nanoparticles: An active system for the reduction of aromatic nitro-compounds
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Synthesis of carbon nitride supported highly dispersed ultrafine palladium nanoparticles has been reported for the reduction of aromatic nitro-compounds using hydrazine hydrate as a reducing agent. As a demonstration, the as-synthesized carbon nitride-palladium composite was shown to be a highly active and chemo-selective for the title reaction. Utilizing the optimized reaction conditions a set of aromatic nitro compounds have been converted to their corresponding amine derivatives with good to excellent yield ranging from 80% to 99%. The catalyst can be used for multiple times without affecting the catalytic performance and can also be stored for a long time at ambient condition maintaining the high catalytic efficiency.
- Nandi, Debkumar,Siwal, Samarjeet,Choudhary, Meenakshi,Mallick, Kaushik
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- Selectivity of the complexation reactions of four regioisomeric methylcamphorquinoxaline ligands with gold(III): X-ray, NMR and DFT investigations
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Reported are the synthesis, spectral and structural characteristics of new quinoxaline-related regioisomeric ligands L1-L4 (1,x,11,11-tetramethyl-1,2,3,4-tetrahydro-1,4-methanophenazine, x = 7, 8, 9 and 6, respectively) and their mononuclear Au(III) complexes (1-4). Fusion of the camphor moiety to the quinoxaline core made two N-atoms of quinoxaline nonequivalent while the introduction of a methyl-substituent at positions 6-9 enabled a tuning of coordination properties of L1-L4. Gold(III) complexes 1-4 and ligands L1-L4 have been studied in detailed by 1D and 2D NMR and the structures of 1-4 have been determined by X-ray crystallography. The results of these analyses revealed a regiospecific coordination of Au(III) to the sterically less hindered N-5 atom (spatially close to the non-substituted bridgehead carbon) of L1-L3, and to N-10 (spatially close to the methyl-substituted bridgehead carbon) of L4. The results of DFT calculations shed light on disparate coordination modes of L1-L4 toward the AuCl3 fragment and explain formation of single coordination products in high yield.
- Gli?i?, Biljana D.,Hoffmann, Marcin,Warzajtis, Beata,Gen?i?, Marija S.,Blagojevi?, Polina D.,Radulovi?, Niko S.,Rychlewska, Urszula,Djuran, Milo? I.
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p. 137 - 149
(2016/01/15)
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- A pyrazine structure containing methyl 1, 2, 4 - triazole derivative and its preparation method and application (by machine translation)
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The invention discloses a pyrazine structure containing methyl 1, 2, 4 - triazole derivative and its preparation method and application. For 4 - methyl O-nitroaniline with hydrazine hydrate to produce compound (II). With the MBF reaction, to obtain the product (III). The compound (III) POCl for3 To obtain the product (IV) chloride. Compound (IV) with hydrazine hydrate and offer to obtain the intermediate product (V). Compound (V) in order to POCl3 As the solvent, with the substituted acid compound the response results in the type (I) shown in methyl pyrazine structure containing 1, 2, 4 - triazole derivatives; its raw material is simple and easy, simple preparation method, after treatment is convenient, high product yield, but the compound is has herbicidal activity, in particular against bentgrasses have good herbicidal effect, to provide the basis for a new pesticide research. (by machine translation)
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Paragraph 0015; 0027
(2017/02/17)
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- A O-phenylenediamine and its derivatives of the preparation method
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The invention relates to a method for synthesizing organic compounds, and provides a method for preparing o-phenylenediamine and a derivative of o-phenylenediamine, for solving the problems that the process route is complex, a great amount of byproducts can be generated and are hard to purify, the reaction condition is rigorous, the environment pollution is severe and the like in a conventional method for synthesizing o-phenylenediamine derivatives. The method disclosed by the invention comprises the following steps: by taking azobenzene and a derivative of the azobenzene as raw materials, synthesizing the o-nitro azobenzene and the derivative of the o-nitro azobenzene under the coactions of a catalyst, an oxidant and a nitrating agent, and further reducing by using a reducing agent, thereby obtaining the o-phenylenediamine and the derivative of the o-phenylenediamine. The method provided by the invention has the advantages that the raw materials are cheap and easy to obtain, the operation is simple, convenient and safe, the synthesis steps are short, the purification is simple, no great waste acid pollution is caused, and the like.
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Paragraph 0052-0054
(2017/07/20)
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- Structure and reactivity of supported hybrid platinum nanoparticles for the flow hydrogenation of functionalized nitroaromatics
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This contribution targets the first comprehensive understanding of the next-generation catalyst for nitroarene hydrogenation, featuring ligand-capped 2 nm platinum nanoparticles (Pt-HHDMA, HHDMA: hexadecyl(2-hydroxyethyl)dimethylammonium dihydrogen phosphate) deposited on carbon. Fundamental questions related to the structure, properties, and mechanistic fingerprints of the metal-organic interphase of the hybrid system were addressed through a battery of advanced characterization methods and theoretical calculations. Catalytic tests conducted in a flow reactor at variable temperature and pressure revealed the superior activity of Pt-HHDMA in comparison with the archetypal and industrially relevant Lindlar-type Pt-Pb/CaCO3, with outstanding chemoselectivity and leaching resistance. The analysis of the reaction mechanism by Density Functional Theory, which was never addressed systematically, showed that the benefits of the ligand-modified catalyst arise from the facilitated H2 activation and weak nitroarene adsorption on the HHDMA-modified surface. At the same time, the ligand isolates the platinum ensemble, reducing the possibility of unselective routes by controlling the adsorption geometry and extent of the reactant and product intermediates. These results substantially enrich the mechanistic understanding of HHDMA-modified Pt catalyst and are of fundamental relevance for future improvements of this hybrid catalyst and for extrapolating this technology to other challenging reactions.
- Vilé, Gianvito,Almora-Barrios, Neyvis,López, Núria,Pérez-Ramírez, Javier
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p. 3767 - 3778
(2015/06/16)
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- Discovery of phenoxybutanoic acid derivatives as potent endothelin antagonists with antihypertensive activity
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A series of phenoxybutanoic acid derivatives were synthesized and tested for their antagonistic activity on the contraction of the rat thoracic aortic ring induced by endothelin-1. Preliminary screening results showed that 6e and 6g with benzoheterocycles demonstrated significant antagonistic activities when compared to the reference compound BQ123. The results from additional assays for the binding affinity and selectivity for endothelin receptors showed that 6e was a selective ETA antagonist with a nanomolar IC50. Moreover, 6e was effective in relieving hypoxia-induced pulmonary arterial hypertension and right ventricular weight ratio. Therefore, 6e may have potential for further development as a therapeutic agent for the treatment of cardiovascular diseases.
- Cai, Jin,Liu, Ligang,Hong, Kwon Ho,Wang, Peng,Li, Lushen,Cao, Meng,Sun, Chunlong,Wu, Xiaoqing,Zong, Xi,Chen, Junqing,Ji, Min
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p. 657 - 667
(2015/02/19)
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- A Highly Water-Dispersible/Magnetically Separable Palladium Catalyst: Selective Transfer Hydrogenation or Direct Reductive N-Formylation of Nitroarenes in Water
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Simple ion exchange of the chloride anion of an ionic-liquid-functionalized magnetic nanoparticle with [PdCl4]2- provided a highly water-dispersible and magnetically separable palladium catalyst that exhibited excellent activity toward transfer hydrogenation reactions in water as a solvent. The catalyst demonstrated outstanding performance in aqueous-phase transfer hydrogenation of various nitroarenes in a highly chemo- and regioselective manner by using HCOONH4 as a low-cost, green, and easily available hydrogen donor. Also, by using only 0.25 mol % of the catalyst and formic acid as both a hydrogen donor and formylating agent, the catalyst showed excellent activity in the one-pot, direct synthesis of N-arylformamides from nitroarenes in water as a solvent. Notably, owing to the presence of a hydrophilic ionic liquid on the surface of silica-coated iron oxide nanoparticles, the catalyst showed highly stable dispersion in water, as evidenced by the zeta potential and extremely low affinity to the organic phase. These features make this catalyst system suitable for an efficient double-separation strategy (successive extraction/final magnetic separation). The recovered aqueous phase containing the catalyst can be simply and efficiently reused in eight runs without a decrease in activity and can be easily separated from the aqueous phase at the end of the process by applying an external magnetic field.
- Karimi, Babak,Mansouri, Fariborz,Vali, Hojatollah
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p. 1750 - 1759
(2016/01/25)
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- Graphene oxide (GO) or reduced graphene oxide (rGO): Efficient catalysts for one-pot metal-free synthesis of quinoxalines from 2-nitroaniline
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A straightforward one-pot preparation of library of quinoxalines from 2-nitroanilines under entirely metal-free conditions is described. Initial reduction of nitroaniline with hydrazine hydrate is efficiently catalyzed by graphene oxide (GO) or reduced graphene oxide (rGO), and further one-pot tandem reactions with 1,2-dicarbonyl compounds or with α-hydroxy ketones afford quinoxalines in excellent yields. The catalyst is recovered, characterized, and found to be recyclable for consecutive four runs examined with appreciable conversions.
- Roy, Babli,Ghosh, Sujit,Ghosh, Pranab,Basu, Basudeb
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supporting information
p. 6762 - 6767
(2016/01/30)
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- Acid-catalyzed hydrolysis of 5-substituted-1H,3H-2,1,3-benzothiadiazole 2,2-dioxides (5-substituted benzosulfamides): Kinetic behavior and mechanistic interpretations
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The acid-catalyzed hydrolysis of a series of 5-substituted-1H,3H-2,1,3-benzothiadiazole 2,2-dioxides has been investigated in aqueous solutions of sulfuric, perchloric, and hydrochloric acid at 85.0 ± 0.05 °C. Analysis of the kinetic data by the excess acidity method, Arrhenius parameters, the order of the catalytic effects of strong acids, the kinetic deuterium isotope effect, and the substituent effect have indicated that the hydrolysis of 5-substituted benzosulfamides 1a, 1b, 1c, 1d occur with a mechanistic switchover from A2 to A1 in the studied range: an A2 mechanism in low acidity regions and an A1 mechanism in high acid concentrations.
- Gediz Erturk, Aliye,Bekdemir, Yunus
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supporting information
p. 358 - 364
(2015/05/05)
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- Synthesis of riboflavines, quinoxalinones and benzodiazepines through chemoselective flow based hydrogenations
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Robust chemical routes towards valuable bioactive entities such as riboflavines, quinoxalinones and benzodiazepines are described. These make use of modern flow hydrogenation protocols enabling the chemoselective reduction of nitro group containing building blocks in order to rapidly generate the desired amine intermediates in situ. In order to exploit the benefits of continuous processing the individual steps were transformed into a telescoped flow process delivering selected benzodiazepine products on scales of 50 mmol and 120 mmol respectively.
- Baumann, Marcus,Baxendale, Ian R.,Hornung, Christian H.,Ley, Steven V.,Rojo, Maria Victoria,Roper, Kimberley A.
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p. 9736 - 9759
(2014/08/05)
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- Synthesis and biological evaluation of 5-substituted derivatives of benzimidazole
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A series of eight novel 5-substituted derivatives of benzimidazole was synthesized by condensation of the corresponding diamine with ethyl 4-[4- -(2-chlorophenyl)piperazin-1-yl]butanoate in refluxing 4 M hydrochloric acid. In vitro antibacterial activity against ten strains, namely Bacillus subtilis, Clostridium sporogenes, Streptosporangium longisporum, Micrococcus flavus, Sarcina lutea, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Proteus vulgaris and antifungal activity against two fungal strains, namely Candida albicans and Saccharomyces cerevisiae, were evaluated. Of all the compounds screened for activity, 2-{3-[4-(2-chlorophenyl) piperazin-1-yl]propyl}-5-iodo-1H-benzimidazole and 2-{3-[4-(2-chlorophenyl) piperazin-1-yl]propyl}-5-methyl-1H-benzimidazole were associated with higher antifungal activity than commercial drugs.
- Vasic, Vesna P.,Penjisevic, Jelena Z.,Novakovic, Irena T.,Sukalovic, Vladimir V.,Andric, Deana B.,Kostic-Rajacic, Sladana V.
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p. 277 - 282
(2014/04/17)
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- Aerobic synthesis of biocompatible copper nanoparticles: Promising antibacterial agent and catalyst for nitroaromatic reduction and C-N cross coupling reaction
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Herein, we report the synthesis of copper nanoparticles at ambient conditions using biopolymer, pectin, as a protecting agent and hydrazine as a reducing agent. The obtained nanoparticles catalyze the reduction of nitroaromatic compounds in aqueous solution and also catalyze the C-N cross coupling of amines with bromobenzene in good yields. This journal is the Partner Organisations 2014.
- Venkatakrishnan, Showmya,Veerappan, Ganapathy,Elamparuthi, Elangovan,Veerappan, Anbazhagan
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p. 15003 - 15006
(2014/04/17)
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- Metallic nanoparticles immobilized in magnetic metal-organic frameworks: Preparation and application as highly active, magnetically isolable and reusable catalysts
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Separation and recycling of catalysts after catalytic reactions are critically required to reduce the cost of catalysts as well as to avoid the generation of waste in industrial applications. In this paper, ultrafine noble metallic nanoparticles are incorporated into cauliflower-like porous magnetic metal-organic frameworks (MOFs). With the restriction effects of the pore/surface structure in the MOFs, "surfactant-free" metallic nanoparticles are successfully obtained on a 2-3 nm scale. In addition, both the thickness of MOFs shell and the content of noble metallic NPs are tunable on the MOFs coating. Moreover, the microspheres exhibit excellent performance for the catalytic reduction of p-nitrophenol with a turnover frequency of 3094 h-1. The uniform cavities in the MOFs shell provide docking sites for p-nitrophenol and act as confinement nanoreactors, which greatly improves the catalytic performance. Most importantly, the magnetically responsive microspheres can be easily recovered by a magnetic field and show excellent reusability. The as-prepared catalyst also shows good activity for the reduction of other nitrobenzenes. Consequently, this work provides a highly active, magnetically isolable, and recyclable catalyst, which can be used for various catalytic industrial processes. The fundamental model can be further employed in a variety of biomedical fields including drug delivery and biological molecules separation. the Partner Organisations 2014.
- Zhang, Hai-Juan,Qi, Sheng-Da,Niu, Xiao-Ying,Hu, Jing,Ren, Cui-Ling,Chen, Hong-Li,Chen, Xing-Guo
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p. 3013 - 3024
(2014/08/18)
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- One pot catalytic NO2 reduction, ring hydrogenation, and N-alkylation from nitroarenes to generate alicyclic amines using Ru/C-NaNO 2
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A report to produce alicyclic amines and subsequent N-alkylation with alcohols using Ru/C-NaNO2 catalyzed facile transformation of nitrobenzene was investigated. Effects of solvent, temperature, pressure, reaction time, and molar-ratio of substrate/catalyst on product composition were also studied. These mechanistic studies explain that nitrobenzene undergoes hydrogenation reaction in the following order; -NO2 reduction to -NH2, aromatic ring-hydrogenation to alicyclic, and from the reaction of alcohol to give N-alkylated amines. This investigation shed lights on possible application to polyurethane chemistry since these amines are used as important precursors for diisocyanates.
- Oh, Seung Geun,Mishra, Vivek,Cho, Jin Ku,Kim, Baek-Jin,Kim, Hoon Sik,Suh, Young-Woong,Lee, Hyunjoo,Park, Ho Seok,Kim, Yong Jin
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- Design, synthesis, quantum chemical studies and biological activity evaluation of pyrazole-benzimidazole derivatives as potent Aurora A/B kinase inhibitors
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Novel pyrazole-benzimidazole derivatives have been designed and synthesized. The entire target compounds were determined against cancer cell lines U937, K562, A549, LoVo and HT29 and were screened for Aurora A/B kinase inhibitory activity in vitro. The compounds 7a, 7b, 7i, 7k and 7l demonstrated significant cancer cell lines and Aurora A/B kinase inhibitory activities. Molecular modeling studies suggested the derivatives have bound in the active site of Aurora A kinase through the formation of four hydrogen bonds. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. The cellular activity of 7k was also tested by immunofluorescence.
- Zheng, Youguang,Zheng, Ming,Ling, Xin,Liu, Yi,Xue, Yunsheng,An, Lin,Gu, Ning,Jin, Min
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supporting information
p. 3523 - 3530
(2013/07/11)
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- Combined Pd/C and montmorillonite catalysis for one-pot synthesis of benzimidazoles
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A series of nineteen benzimidazoles were prepared from ortho-nitroanilines by one-pot transfer hydrogenation, condensation, and dehydrogenation enabled by the concurrent use of two heterogeneous catalysts: montmorillonite-K10 and Pd/C. This strategy was further employed to accomplish a five-step, three-component synthesis of an antifungal benzimidazoquinazoline by using a simple one-pot procedure.
- Weires, Nicholas A.,Boster, Jared,Magolan, Jakob
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supporting information
p. 6508 - 6512
(2013/01/15)
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- Bakers' yeast-catalyzed ring opening of benzofuroxans: An efficient green synthesis of aryl-1,2-diamines
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A simple and inexpensive method for the reductive cleavage of N-O bond of benzofuroxans with bakers' yeast under nonfermenting condition in aqueous media was achieved. The procedure gives excellent yields of aryl-1,2-diamines. Copyright Taylor & Francis Group, LLC.
- Borah, Harsha N.,Prajapati, Dipak,Boruah, Romesh C.
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scheme or table
p. 267 - 272
(2009/04/07)
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- A facile one-pot synthesis of benzimidazoles from 2-nitroanilines by reductive cyclization
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A facile one-pot process to prepare benzimidazole derivatives is described. Reductive cyclization of a serial of 2-nitroanilines with orthoesters in the presence of Pd/C in methanol at room temperature, which is promoted by a catalytic amount of acetic acid, affords the corresponding benzimidazole derivatives in high yields.
- Liu, Zheng,Li, Haihong,Zhao, Qingjie,Shen, Jingshan
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scheme or table
p. 1907 - 1911
(2009/04/06)
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- Efficient method for the synthesis of benzimidazoquinazoline derivatives with three-point diversity
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An efficient strategy for the preparation of a novel heterocyclic ring system of benzimidazoquinazolines with three-point diversity has been described. The compounds were obtained by treating o-phenylene diamines with o-nitrobenzaldehyde to give benzimidazoles, followed by reduction of the nitro group to give an amine. Derivatization of the resulting amine with isothiocyanates followed by in situ cyclodesulfurization at rt furnished the title compounds in high yields and purities. Copyright Taylor & Francis Group, LLC.
- Saha, Biswajit,Sharma, Sunil,Kundu, Bijoy
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p. 3455 - 3470
(2008/02/13)
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- Benzimidazole compound
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An object of the present invention is to provide a novel chemical compound useful as a therapeutic or prophylactic agent for acid-related diseases, having an excellent inhibitory effect against gastric acid secretion, an excellent effect of maintaining the inhibitory effect against gastric acid secretion, thereby maintaining intragastric pH high for a long time, and having more safety and appropriate physicochemical stability. Provided is a compound represented by where R1 and R3 may be the same or different and each represent a hydrogen atom or a C1-C6 alkyl group; R2 represents (5,5-dimethyl-1,3-dioxan-2-yl)methoxy group, 5,7-dioxaspiro[2.5]oct-6-ylmethoxy group, 1,5,9-trioxaspiro[5.5]undec-3-ylmethoxy group, or (2,2-dimethyl-1,3-dioxan-5-yl)methoxy group; R4, R5, R6 and R7 represent a hydrogen atom, halogen atom, C1-C6 alkyl group, C1-C6 haloalkyl group, C1-C6 alkoxy group or C1-C6 haloalkoxy group; and W1 represents a single bond, methylene or ethylene group, a salt thereof or a solvate of these.
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Page/Page column 71-72
(2008/06/13)
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- Process for the production of the toluene diisocyanate
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The invention relates to a process for the production of toluene diisocyanate, in which the crude toluenediamine obtained from the hydrogenation is purified and then phosgenated. The purification step reduces the total amount of cyclic ketones to less than 0.1 % by weight, based on 100% by weight of the toluenediamine.
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Page/Page column 5; 6
(2008/06/13)
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- Samarium diiodide mediated regeneration of 1,2-benzenediamine and preparation of benzimidazolin-2-ones from 2,1,3-benzothiadiazoles
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On treatment with Sml3 in THF and in the presence of methanol, 2,1,3-benzothiadiazoles underwent reductive N-S bond cleavage leading to 1,2-benzenediamines in high yields. Without methanol but in the presence of triphosgene, benzimidazolin-2-ones were obtained in moderate yields under mild conditions.
- Fan, Xuesen,Zhang, Xinying,Zhang, Yongmin
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- N-cyanoethylated ortho and meta toluenediamine compounds
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The invention provides N-cyanoethylated toluenediamines (CNTDAs), processes for synthesizing them, and compositions containing them. In preferred embodiments, the CNTDAs are represented by the following formula: where the nitrogen atoms are ortho or meta to each other on the aromatic ring. The CNTDAs are particularly suitable for use as latent curing agents for epoxy resins.
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- N-(Aminopropyl)-toluenediamines and their use as epoxy curing agents
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The invention provides N-aminopropylated toluenediamines, processes for synthesizing them, compositions containing them and methods for using them to cure epoxy resins. In preferred embodiments, the N-aminopropylated toluenediamines are represented by the following formula: where the nitrogen atoms are ortho or meta to each other on the aromatic ring.
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- N-Cyanoethylated ortho and meta toluenediamine compositions and process for making them
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The invention provides N-cyanoethylated toluenediamines (CNTDAs), processes for synthesizing them, and compositions containing them. In preferred embodiments, the CNTDAs are represented by the following formula: where the nitrogen atoms are ortho or meta to each other on the aromatic ring. The CNTDAs are particularly suitable for use as latent curing agents for epoxy resins.
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- N-(aminopropyl)-toluenediamines and their use as epoxy curing agents
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The invention provides N-aminopropylated toluenediamines, processes for synthesizing them, compositions containing them and methods for using them to cure epoxy resins. In preferred embodiments, the N-aminopropylated toluenediamines are represented by the following formula: where the nitrogen atoms are ortho or meta to each other on the aromatic ring.
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- Solvent-free reduction of aromatic nitro compounds with alumina-supported hydrazine under microwave irradiation
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Aromatic nitro compounds are readily reduced to the corresponding amino compounds in good yield with hydrazine hydrate supported on alumina in the presence of FeCl3·6H2O, Fe(III) oxide hydroxide or Fe(III) oxides.
- Vass, András,Dudás, József,Tóth, Judit,Varma, Rajender S.
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p. 5347 - 5349
(2007/10/03)
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- A practical method for the reduction of 2,1,3-benzothiadiazoles to 1,2-benzenediamines with magnesium and methanol
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A new and practical method for the reduction of 2,1,3-benzothiadiazoles to 1,2-benzenediamines with magnesium and methanol is described. Sensitive functional groups such as bromo, chloro, cyano, and ester are well tolerated under these new conditions.
- Prashad, Mahavir,Liu, Yugang,Repi?, Oljan
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p. 2277 - 2279
(2007/10/03)
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- Photoinduced Nitro-Nitrite Rearrangement of 5-Nitroquinoxalines
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Unlike known o-nitro methyl derivatives of aromatic compounds, 6-methyl-5-nitro-, 2,3,6-trimethyl-5-nitro-, and 7-methyl-6-nitroquinoxaline and 1,6-dimethyl-5-nitroquinoxalinium perchlorate do not exhibit photochromism in aqueous-ethanolic solutions under conditions of flash photolysis with a time resolution of 50 μs. Under conditions of continuous photolysis, these 5-nitromethylquinoxaline derivatives and also 5-nitroquinoxaline undergo nitro-nitrite rearrangement to give 5-quinoxalinol derivatives with quantum yields ranging from 1 × 10-4 to 3 × 10-3; the efficiency of the photochemical reaction increases when irradiation is performed with a shorter-wave light. 6-Nitro derivatives do not form stable products of photochemical transformations under the same conditions.
- El'tsov,Selitrenikov,Rtishchev
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p. 285 - 294
(2007/10/03)
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- Monoazo or disazo pigments based on (benoxazol-2-yl)- or (benzimidazol-2-yl)-arylacetamides
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Water-insoluble azo colorants, their preparation and use The invention relates to monoazo and disazo compounds of the formula (I) STR1 in which D is the radical of a carbocyclic or heterocyclic diazo or bisdiazo component, R1 and R2, independently of one another, are each a substituted or unsubstituted aryl or heteroaryl radical, X1 and X2, independently of one another, are each ring-forming ether oxygen or a substituted or unsubstituted imide grouping and n has the value 0 or 1, in which rings A and B, independently of one another, can each be additionally substituted and/or carry substituted or unsubstituted fused rings. These new compounds of the formula (I) are obtained by coupling diazotized amines or diamines of the type D--NH2 or H2 N--D--NH2 with (benzoxazol-2-yl)- or (benzimidazol-2-yl)-arylacetamides. Depending on the presence and length of alkyl chains, the compounds of the formula (I) are suitable for use as pigments, disperse dyes or oil-soluble dyes.
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- Ammonium sulphate - Magnesium promoted selective reduction of aromatic nitro compounds
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Various nitroarenes and 2,1,3-benzooxadiazole-1-oxides were selectively and rapidly reduced to their corresponding amino and diamino compounds respectively in high yields using (NH4)2SO4-Mg/Al/Bi, a new reduction system.
- Prajapati,Borah,Sandhu,Ghosh
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p. 4025 - 4028
(2007/10/03)
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- NITRO DERIVATIVES OF AROMATIC AZOXY COMPOUNDS. PART I. 2,2'- AND 4,4'-DIMETHYLAZOXYBENZENE NITRATION PRODUCTS
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By nitration of 2,2'-dimethylazoxybenzene (1) with concentrated nitric acid under conditions of increasing severity we obtained in succession nitro derivatives having their nitro groups in position: 4; 3',4 and 2,3',4.From 4,4'-dimethylazoxybenzene (2) we obtained similar products with nitro groups in positions: 2,3' (plus 2,6-isomer) and 2,3',6.Trinitro derivatives were obtained also by nitration of dinitro compounds, while tetranitro derivatives: 2,3',4,5' and 2,3',5',6 were obtained by nitrating trinitro compounds (in the presence of phosphoric acid).By reduction with stannous chloride in a strongly acidic medium we obtained, parallel to monocyclic aromatic amines and the conventional benzidine rearrangement products, also 4,4'-dimethyl-2,3'-diaminoazoxybenzene from dinitro derivative 2b, and 3,3'-dimethylbenzidine from mononitro derivative 1a, the latter being quite unexpected.
- Urbanski, Jerzy,Wolak, Ireneusz
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p. 1035 - 1045
(2007/10/02)
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- A GENERAL PROCEDURE FOR MILD AND RAPID REDUCTION OF ALIPHATIC AND AROMATIC NITRO COMPOUNDS USING AMMONIUM FORMATE AS A CATALYTIC HYDROGEN TRANSFER AGENT
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Various aliphatic and aromatic nitro compounds were selectively and rapidly reduced to their corresponding amino derivatives in very good yield using anhydrous ammonium formate as a catalytic hydrogen transfer agent.
- Ram, Siya,Ehrenkaufer, Richard E.
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p. 3415 - 3418
(2007/10/02)
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- Process for the manufacture of benzimidazolones-(2)
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Process for the manufacture of benzimidazolones-(2) wherein an o-phenylenediamine is reacted with optionally alkylated urea in the ratio of 1 to 1.3 moles per mole o-phenylenediamine in an organic solvent which has a solubility in water of not more than 5 g/l and has a boiling point above 100° C, at a temperature between 100° and 200° C.
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