- The dihydropyrone Diels-Alder reaction: Development and application to the synthesis of highly functionalized 1-oxa-4-decalones
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A facile method for the synthesis of highly functionalized 1-oxadecalone derivatives is described via the Diels-Alder reaction of 2,3-dihydro-4-pyrone dienophiles with electron rich dienes. By this process a variety of functional groups and substitution patterns can be incorporated into the oxadecalone framework. (C) 2000 Elsevier Science Ltd.
- Seth, Punit P.,Chen, Deqi,Wang, Junquan,Gao, Xiuchun,Totah, Nancy I.
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- Conformational, structural, vibrational and quantum chemical analysis on 4-aminobenzohydrazide and 4-hydroxybenzohydrazide-A comparative study
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Experimental and theoretical quantum chemical studies were carried out on 4-hydroxybenzohydrazide (4HBH) and 4-aminobenzohydrazide (4ABH) using FTIR and FT-Raman spectral data. The structural characteristics and vibrational spectroscopic analysis were carried performed by quantum chemical methods with the hybrid exchange-correlation functional B3LYP using 6-31G, 6-311++G and aug-cc-pVDZ basis sets. The most stable conformer of the title compounds have been determined from the analysis of potential energy surface. The stable molecular geometries, electronic and thermodynamic parameters, IR intensities, harmonic vibrational frequencies, depolarisation ratio and Raman intensities have been computed. Molecular electrostatic potential and frontier molecular orbitals were constructed to understand the electronic properties. The potential energy distributions (PEDs) were calculated to explain the mixing of fundamental modes. The theoretical geometrical parameters and the fundamental frequencies were compared with the experimental. The interactions of hydroxy and amino group substitutions on the characteristic vibrations of the ring and hydrazide group have been analysed.
- Arjunan,Jayaprakash,Carthigayan,Periandy,Mohan
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- Trifluoromethanesulfonic acid immobilized on zirconium oxide obtained by the sol-gel method as catalyst in paraben synthesis
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The parabens, alkylic esters of p-hydroxybenzoic acid, were synthesized using trifluoromethanesulfonic acid immobilized on zirconium oxide (zirconia) as catalyst. The oxide was obtained by the sol-gel method, using urea as a pore-forming agent. After removing urea by extraction with water, the solid was dried and then calcined at 100, 205, 310 and 425 °C for 24 h. Afterward, it was impregnated with trifluoromethanesulfonic acid in toluene at reflux and leached to remove the weakly adsorbed acid. Mesoporous materials were obtained, whose mean pore diameter increased with the temperature of the thermal treatment of the support, while the specific surface area and the amount of acid bonded to the support decreased. The samples are crystalline from 400 °C and are thermally stable up to 250 °C. The catalysts have strong acidity and the number of acid sites decreased with the acid content in the support. The catalytic activity in the synthesis of propyl paraben, expressed as moles of ester formed at 5 h/mol acid in the catalyst, decreased when samples obtained from supports thermally treated at higher temperature were used. The activity also slightly diminished for the synthesis of different parabens in the order propyl > ethyl > methyl ester.
- Gorsd, Marina,Pizzio, Luis,Blanco, Mirta
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- Synthesis, characterization and antimicrobial evaluation of novel (E)-N′-(4-(1-((3,4-dimethoxypyridin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)benzylidene)benzohydrazide derivatives
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The synthesis of novel 1,2,3-triazole-hydrazone derivatives embedded with 3,4-dimethoxy pyridine ring nucleus is described. These derivatives were prepared utilizing, 2-(chloromethyl)-3,4-dimethoxypyridine 1, 4-ethynylbenzaldehye 5 and various benzohydrazides7a-7j. The structures of the newly synthesized 1,2,3-triazole-hydrazones 8a-j was established on the basis of the spectroscopic techniques like 1H NMR, mass and IR data. They were evaluated against a panel of bacterial and fungal pathogens such as Staphylococcus. pyogens, Staphylococcus. Aureus (Gram positive bacteria), Escherichia.coli, Pseudomonas. aeruginosa (Gram negative bacteria) and Aspergillus niger and Candida albicans (Fungal stains). Compounds 8b, 8c, 8d, 8e and 8f with R = 4-OH, 4-OMe, 4-SO2Me, 3,45,-OMe and 3-NO2 respectively showed moderate antibacterial activity while compounds 8b, 8d, 8i and 8j with R = 4-OH, 4-SO2Me, 3,5-dichloro and 2,5-difluoro substitution exhibited very good fungal activity.
- Saidugari, Swamy,Vadali, Lakshmana Rao,Vidya,Ram
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- Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole derivatives as anti-breast cancer agents
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Structural based molecular docking approach revealed the findings of 2-(phenoxymethyl) -5-phenyl-1,3,4-oxadiazole derivatives. The compounds (7a-o) were synthesized and characterized well by using conventional methods. The compounds, 7b and 7m were reconfirmed through single crystal XRD analysis. The synthesized compounds (7a-o) were evaluated their antiproliferative activities against MCF-7 and MDA-MB-453. Furthermore, Lipinski's rule of five and pharmacokinetic properties were predicted for the test compounds. These results demonstrate that the compounds 7b and 7d exhibit more potent cytotoxicity and 7d exhibits dose-dependent activity and reduced cell viability. Further, the mechanism of action for the induced apoptosis was observed through morphological changes and western blotting analysis. These findings may furnish the lead for further development.
- Lakshmithendral,Saravanan,Elancheran,Archana,Manikandan,Arjun,Ramanathan,Lokanath,Kabilan
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- Novel Benzothiazole Ionic Liquids as Catalysts for the Synthesis of Parabens
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Abstract: A simple and green approach to the esterification of p-hydroxybenzoic acid and aliphatic alcohols to obtain parabens was developed. First, two novel benzothiazole ionic liquids [HBth]H2PW12O40 (IL1) and [HBth]H4PMo12O41 (IL2) were synthesized with benzothiazole and heteropolyacids as starting materials. The synthesized ionic liquids were characterized by FTIR spectroscopy, TGA, PXRD analysis, and SEM. The application of IL1 and IL2 as catalysts for the synthesis of parabens was explored. The results showed that the ILs had a high catalytic activity in the synthesis of parabens, and, at the same time, they could be easily recovered and reused five times without loss of activity.
- Liu, B.,Liu, Y.,Sun, J.,Yin, D.
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- Construction of cis-azadecalone units via novel intermolecular Diels-Alder reaction
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N-Methoxycarbonyl-5-ethoxycarbonyl-2,3-dihydropyridin-4-one 1 reacts under thermal or Lewis acid-catalysed conditions with trimethylsilyloxybutadienes to give cis-azadecalones via a formal [4+2] cycloaddition.
- Dhimane, Hamid,Meunier, Stéphane,Vanucci-Bacqué, Corinne,Lhommet, Gérard
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- One billionhertz microwave athermal action on the synthesis of aromatic esters at normal pressure
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Benzoic acid or p-hydroxybenzoic acid undergoes rapid reaction with alcohol using H2SO4 as catalyst at normal pressure, under irradiating continuously of the 1 GHz and 50 mW microwave for 22-60 minutes to afford aromatic esters in 76-90% yields.
- Zhang,Zhou,Zhang,Wu,Chen
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- Synthesis of Nipagin esters using acidic functional ionic liquids as catalysts
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(Chemical Equation Presented) Several Bronsted acidic functional ionic liquids (FILs) with an alkane sulfonic acid group were synthesized. These FILs as dual solvent-catalysts for Nipagin esterification reactions were investigated. The results indicated that [HSO3-pMIM]HSO4 has the best catalytic activity and recyclability among the various kinds of FILs investigated, and its structure was characterized by infrared and NMR. The [HSO3-pMIM]HSO4 could be easily separated from the reaction mixture and reused without noticeably decreasing the catalytic activity. Copyright Taylor & Francis Group, LLC.
- Wang, Guohua,Li, Lu,Xie, Congxia,Yu, Shitao,Liu, Fusheng,Ye, Xiaoling
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- Correlation of antioxidant activities with theoretical studies for new hydrazone compounds bearing a 3,4,5-trimethoxy benzyl moiety
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A new series of antioxidants, namely imines bearing the well-known free radical scavenger group 3,4,5-trimethoxybenzyloxy, was designed and synthesized. Theoretical calculations based on density functional theory (DFT) were performed to understand the antioxidant activities. Experimental studies evaluating the antioxidant activities of the compounds using DPPH and FRAP assays verified the predictions obtained by DMOL3 based on DFT.1. The DPPH radical scavenging activities depended on the substitution pattern of the aromatic aldehyde, with both the substitution type and position showing significant effects. Compounds 7b, 7c and 7d, which contain a phenolic hydroxyl group at the para position to the imine as well as, additional electron donating groups at the ortho-position to this hydroxyl group, exhibited IC50 values of 62, 75 and 106 μg/mL, respectively, and potent antioxidant activities against DPPH, which were better than that of the reference compound BHT. With the exception of compounds 7a and 7h with a phenolic hydroxyl group at the ortho position, all of the investigated compounds exhibited ferric reducing activities above 1000 μM. Correlation analysis between the two antioxidant assays revealed moderate positive correlation (r = 0.59), indicating differing antioxidant activities based on the reaction mechanism. Therefore, imines bearing a 3,4,5-trimethoxybenzyloxy group can be proposed as potential antioxidants for tackling oxidative stress.
- Kareem, Huda S.,Ariffin, Azhar,Nordin, Nurdiana,Heidelberg, Thorsten,Abdul-Aziz, Azlina,Kong, Kin Weng,Yehye, Wageeh A.
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- The influence of the thioalkyl terminal group on the mesomorphic behavior of some 6-alkoxy-2-naphthoates derived from 1,3,4-oxadiazole
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A new series of mesogenic compounds having a naphthalene moiety has been synthesized by esterification of 4-(5-(alkyllthio)-1,3,4-oxadiazol-2-yl)phenol and 6-alkoxy-2-naphthoic acid and their liquid crystalline properties have been studied. All the members of the series are enantiotropic and exhibit smectic as well as nematic mesophase. The plot of transition temperatures versus number of carbon atoms in the alkoxy chain exhibits no odd even effect and falling tendency for isotropic transition temperatures. High anisotropy, linearity confers rich mesomorphic properties on the system.
- Chothani,Akbari,Patel,Patel
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- UV-stability and UV-protective activity of alkaloids from the marine sponge Zyzzya fuliginosa
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Alkaloids from the marine sponge Zyzzya fuliginosa damirones A (1) and B (2); makaluvamines H (3), C (4), G (5), and L (6); and zyzzyanones A (8) and B (9) were investigated for the ability to protect egg-cell membranes of the sea urchin Strongylocentrotus nudus from UV-radiation. Damirones, zyzzyanones, and tricyclic makaluvamines C (4) and H (3) exhibited the greatest membrane-protective activity. It was shown that makaluvamines G (5) and L (6) were converted by UV-irradiation into damirones A (1), B (2), tricyclic makaluvamines H (3), C (4), and zyzzyanones A (8) and B (9), respectively. 2006 Springer Science+Business Media, Inc.
- Makarchenko,Utkina
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- ZnII and CdII MOFs based on an amidoisophthalic acid ligand: Synthesis, structure and catalytic application in transesterification
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Solvothermal reaction of zinc(ii) and cadmium(ii) salts with 5-propionamidoisophthalic acid (H2L1) and 5-benzamidoisophthalic acid (H2L2) in the presence or absence of an auxiliary ligand gives rise to a series of 1D, 2D and 3D Zn(ii) or Cd(ii) self-assembled metal-organic frameworks as revealed by X-ray diffraction structural analyses: [Zn(μ-L1-μ-1κOO′:2κO′′)(formamide)2]n (1), [{Zn2(μ-L1-1κO:2κO′)2(4,4′-bipyridine)2(H2O)}·2(DMF)·5(H2O)]n (2), [Cd(μ-L1-μ-1κO2O′:2κO′′2O′′′)(DMF)]n (3), [{Zn(μ-L2-1κO:2κO′)(4,4′-bipyridine)(H2O)}·(H2O)]n (4) and [{Cd(μ-L2-μ-1κO2O′:2κO′′2O′′′)(formamide)(4,4′-bipyridine)}·(formamide)]n (5), which are also characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. The different architectures found in 1-5 result from the coordination modes of the carboxylate groups, which can assume nonbridging monodentate (in 1, 2 and 4), bridging bidentate (also in 1), bridging chelate (in 3 and 5) and chelate bidentate (also in 5) coordination. While 1 and 5 possess one dimensional double chain type structures, 3 has a 1D cyclic type structure and 2 and 4 have 2D or 3D wave-like structures, respectively. Topological analysis has shown that 1 and 5 have a 3-connected uninodal net with a topological type SP1-periodic net, 2 has a 2,4-connected binodal net, 3 has a 4-connected uninodal net structure and 4 has a more complex 2,2,2,4-connected tetranodal net. Frameworks 1-5 act as heterogeneous catalysts for the transesterification reaction of different carboxylate esters, with 4 showing the highest activity. These heterogeneous catalysts can be recycled without losing activity.
- Karmakar, Anirban,Rúbio, Guilherme M. D. M.,Guedes da Silva, M. Fátima C.,Ribeiro, Ana P. C.,Pombeiro, Armando J. L.
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- Development of hydrogel lenses with surface-immobilized PEG layers to reduce protein adsorption
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This paper describes the synthesis and characterization of a series of poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogel lenses coated with poly(ethylene glycol) (PEG) chains. A novel tri-branched PEG-substituted hydrazide is synthesized, which imparts densely packed, covalently bound PEG layers on hydrogels, to determine whether branching provides improved coverage of the lens surface, thereby reducing protein adsorption. Surface modification of hydrogels with PEG was performed via amide-coupling reactions between PEG-substituted hydrazide and the pHEMA matrix. Protein adsorption, water content, optical transparency, and surface properties of the hydrogels were investigated. The hydrogels exhibited transmittance of >90% and improved surface hydrophilicity. Notably, the amount of lysozyme adsorbed on tri-branched PEGcoated hydrogels decreased significantly compared to the amount adsorbed onto the surface of control and linear PEG-coated hydrogels. These results provide insight into the mechanism by which PEGs reduce lysozyme adsorption and suggest that PEG coating may offer an intriguing potential for ophthalmic biomaterials as well as protein-resistant devices.
- Jee, Jun-Pil,Kim, Ho-Joong
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- Using m icrowave and ultrasound to synthesis of substituted bis-acyl hydrazone derivatives
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In this paper, some new bis-acyl hydrazone derivatives (4a-f) were prepared through the reaction of carboxylic acid hydrazides with 1,4-diacetylbenzene using classical methods, microwave and ultrasound irradiation methods. These compounds are obtained through a series of reactions where some carboxylic acids react with ethanol first in the presence of concentrated sulfuric acid to give the corresponding esters (2a-f), which when treatment with aqueous hydrazine give carboxylic acid hydrazides (3a-f).thus, The results proved that the use of microwave and ultrasound techniques is much better than the classical methods, as it gave a higher yield, shorter reaction time, and the absence of the use of solvents. All newly synthesized compounds were confirmed by IR, (1H & 13C) NMR spectral analysis and the corresponding reactions were monitored by TLC using the reported eluent.
- Mohammed, Salim J.,Sheat, Attallah M.,A.abood, Salih,Yahya, Omar M.
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p. 6423 - 6427
(2021/11/01)
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- Design, synthesis, and biological evaluation of new raloxifene analogues of improved antagonist activity and endometrial safety
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Raloxifene agonism of estrogen receptor (ER) in post-menopausal endometrium is not negligible. Based on a rational drug design workflow, we synthesized 14 analogues of raloxifene bearing a polar group in the aromatic ring of the basic side chain (BSC) and/or changes in the bulkiness of the BSC amino group. Analogues with a polar BSC aromatic ring and amino group substituents of increasing volume displayed increasing ER antagonism in Ishikawa cells. Analogues with cyclohexylaminoethoxy (13a) or adamantylaminoethoxy BSC (13b) lacking a polar aromatic ring displayed high ER-binding affinity and ER antagonism in Ishikawa cells higher than raloxifene and similar to fulvestrant (ICI182,780). The endometrial surface epithelium of immature female CD1 mice injected with 13b was comparable to that of vehicle-treated mice, while that of mice treated with estradiol, raloxifene or 13b in combination with estradiol was hyperplastic. These findings indicate that raloxifene analogues with a bulky BSC amino group could provide for higher endometrial safety treatment of the menopausal syndrome.
- Lambrinidis, George,Gouedard, Cedric,Stasinopoulou, Sotiria,Angelopoulou, Angeliki,Ganou, Vassiliki,Meligova, Aggeliki K.,Mitsiou, Dimitra J.,Marakos, Panagiotis,Pouli, Nicole,Mikros, Emmanuel,Alexis, Michael N.
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supporting information
(2020/12/07)
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- Novel arylcarbamate-N-acylhydrazones derivatives as promising BuChE inhibitors: Design, synthesis, molecular modeling and biological evaluation
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A novel series of arylcarbamate-N-acylhydrazones derivatives have been designed and synthesized as potential anti-cholinesterase agents. In vitro studies revealed that these compounds demonstrated selective for butyrylcholinesterase (BuChE) with potent inhibitory activity. The compounds 10a-d, 12b and 12d were the most potent BuChE inhibitors with IC50 values of 0.07–2.07 μM, highlighting the compound 10c (IC50 = 0.07 μM) which showed inhibitory activity 50 times greater than the reference drug donepezil (IC50 = 3.54 μM). The activity data indicates that the position of the carbamate group in the aromatic ring has a greater influence on the inhibitory activity of the derivatives. The enzyme kinetics studies indicate that the compound 10c has a non-competitive inhibition against BuChE with Ki value of 0.097 mM. Molecular modeling studies corroborated the in vitro inhibitory mode of interaction and show that compound 10c is stabilized into hBuChE by strong hydrogen bond interaction with Tyr128, π-π stacking interaction with Trp82 and CH?O interactions with His438, Gly121 and Glu197. Based on these data, compound 10c was identified as low-cost promising candidate for a drug prototype for AD treatment.
- Yamazaki, Diego A.S.,Rozada, Andrew M.F.,Baréa, Paula,Reis, Elaine C.,Basso, Ernani A.,Sarragiotto, Maria Helena,Seixas, Flávio A.V.,Gauze, Gisele F.
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- Design, synthesis, in vitro and in vivo evaluation against MRSA and molecular docking studies of novel pleuromutilin derivatives bearing 1, 3, 4-oxadiazole linker
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A class of pleuromutilin derivatives containing 1, 3, 4-oxadiazole were designed and synthesized as potential antibacterial agents against Methicillin-resistant staphylococcus aureus (MRSA). The ultrasound-assisted reaction was proposed as a green chemistry method to synthesize 1, 3, 4-oxadiazole derivatives (intermediates 85–110). Among these pleuromutilin derivatives, compound 133 was found to be the strongest antibacterial derivative against MRSA (MIC = 0.125 μg/mL). Furthermore, the result of the time-kill curves displayed that compound 133 could inhibit the growth of MRSA in vitro quickly (- 4.36 log10 CFU/mL reduction). Then, compound 133 (- 1.82 log10 CFU/mL) displayed superior in vivo antibacterial efficacy than tiamulin (- 0.82 log10 CFU/mL) in reducing MRSA load in mice thigh model. Besides, compound 133 exhibited low cytotoxicity to RAW 264.7 cells. Molecular docking studies revealed that compound 133 was successfully localized in the binding pocket of 50S ribosomal subunit (ΔGb = -10.50 kcal/mol). The results indicated that these pleuromutilin derivatives containing 1, 3, 4-oxadiazole might be further developed into novel antibiotics against MRSA.
- Liu, Jie,Zhang, Guang-Yu,Zhang, Zhe,Li, Bo,Chai, Fei,Wang, Qi,Zhou, Zi-Dan,Xu, Ling-Ling,Wang, Shou-Kai,Jin, Zhen,Tang, You-Zhi
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- Synthesis and mesomorphic characterization of some novel steroidal mesogens: A structure–property correlation
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The steroidal derivatives are found to be extremely good mesogens since their inception. Because of their inherent chirality, they have the potential to induce a wide variety of liquid crystalline phases, including frustrated phases depending upon the structure of the steroidal skeleton and the substituents attached. In this report, a series of novel monoalkoxy and dialkoxy benzoate derivatives of ergosterol and a few monoalkoxy derivatives of stigmasterol have been synthesized and their mesomorphic property has been investigated. The derivatives exhibited various mesophases including SmA, SmC*, N*, TGB and blue phases. Also, the gelation ability of some of these derivatives with various organic solvents has been examined. Furthermore, the mesomorphism of these derivatives has been compared with the analogous cholesteryl counterparts.
- Bhat S, Vanishree,Kumar, Sandeep,Raghunathan, V. A.
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- Pleuromutilin derivative with 1, 3, 4-oxadiazole side chain and preparation and application thereof
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The invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with a 1, 3, 4-oxadiazole side chain and preparation and application thereof The pleuromutilin derivative with the 1, 3, 4-oxadiazole side chain is a compound shown in a formula 2 or a pharmaceutically acceptable salt thereof, and a solvent compound, an enantiomer, a diastereoisomer and a tautomer of the compound shown in the formula 2 or the pharmaceutically acceptable salt thereof or a mixture of the solvent compound, the enantiomer, the diastereoisomer and the tautomer in any proportion, including a racemic mixture. The pleuromutilin derivative has good antibacterial activity, is especially suitable for being used as a novel antibacterial agent for systemic system infection of animals or human beings, and has good water solubility.
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Paragraph 0055-0056; 0070; 0090; 0092; 0095; 0103
(2021/07/24)
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- One-pot production of diethyl maleate via catalytic conversion of raw lignocellulosic biomass
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The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g-1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment.
- Cai, Zhenping,Chen, Rujia,Jiang, Lilong,Li, Fukun,Li, Xuehui,Long, Jinxing,Zhang, Hao
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supporting information
p. 10116 - 10122
(2021/12/24)
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- Aryl phenol compound as well as synthesis method and application thereof
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The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
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Paragraph 0088-0091
(2021/05/12)
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- Substituent and Surfactant Effects on the Photochemical Reaction of Some Aryl Benzoates in Micellar Green Environment?
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In this study, we carried out preparative and mechanistic studies on the photochemical reaction of a series of p-substituted phenyl benzoates in confined and sustainable micellar environment. The aim of this work is mainly focused to show whether the nature of the surfactant (ionic or nonionic) leads to noticeable selectivity in the photoproduct formation and whether the electronic effects of the substituents affect the chemical yields and the rate of formation of the 5-substituted-2-hydroxybenzophenone derivatives. Application of the Hammett linear free energy relationship (LFER) on the rate of formation of benzophenone derivatives, on the lower energy band of the UV-visible absorption spectra of the aryl benzoates and 5-substituted-2-hydroxybenzophenone derivatives allows a satisfactory quantification of the substituent effects. Furthermore, UV-visible and 2D-NMR (NOESY) spectroscopies have been employed to measure the binding constant Kb and the location of the aryl benzoates within the hydrophobic core of the micelle. Finally, TD-DFT calculations have been carried out to estimate the energies of the absorption bands of p-substituted phenyl benzoates and 5-substituted-2-hydroxybenzophenone derivatives providing good linear correlation with those values measured experimentally.
- Siano, Gastón,Crespi, Stefano,Bonesi, Sergio M.
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p. 1298 - 1309
(2021/05/07)
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- Radical-anion coupling through reagent design: hydroxylation of aryl halides
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The design and development of an oxime-based hydroxylation reagent, which can chemoselectively convert aryl halides (X = F, Cl, Br, I) into phenols under operationally simple, transition-metal-free conditions is described. Key to the success of this approach was the identification of a reducing oxime anion which can interact and couple with open-shell aryl radicals. Experimental and computational studies support the proposed radical-nucleophilic substitution chain mechanism.
- Chechik, Victor,Greener, Andrew J.,James, Michael J.,Oca?a, Ivan,Owens-Ward, Will,Smith, George,Ubysz, Patrycja,Whitwood, Adrian C.
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p. 14641 - 14646
(2021/11/17)
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- Discovery and characterization of a novel perylenephotoreductant for the activation of aryl halides
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To develop a photocatalyst with catalytical activity for substrates with low reactivities is always highly desired. Herein, based on the principle of structure–property relationships, we rationally designed the natural product cercosporin, the naturally occurring perylenequinonoid pigment, to develop a novel organic perylenephotoreductant, hexacetyl reduced cercosporin (HARCP), through structural manipulation. Compared with cercosporin, HARCP shows prominent electrochemical and photophysical characteristics with greatly improved photoreductive activity, fluorescence lifetime and fluorescence quantum yield. These properties allowed HARCP as a powerful photoreductant to efficiently realize a series of benchmark reactions, including photoreduction, alkoxylation and hydroxylation to construct C–H and C–O bonds using aryl halides as substrates under mild conditions, all of which have never been achieved by the same photocatalyst. Thus, this study well supports the notion that the principle between structural manipulation and photocatalytic activity is of great significance to design customized photocatalysts for photoredox chemistry.
- Guo, Baodang,Huang, Shuping,Li, Jia,Li, Min,Liu, Xuanzhong,Rao, Yijian,Wu, Yawen,Yin, Huimin,Yuan, Zhenbo,Zhang, Yan
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p. 111 - 120
(2021/06/16)
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- Biocatalytic Cross-Coupling of Aryl Halides with a Genetically Engineered Photosensitizer Artificial Dehalogenase
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Devising artificial photoenzymes for abiological bond-forming reactions is of high synthetic value but also a tremendous challenge. Disclosed herein is the first photobiocatalytic cross-coupling of aryl halides enabled by a designer artificial dehalogenase, which features a genetically encoded benzophenone chromophore and site-specifically modified synthetic NiII(bpy) cofactor with tunable proximity to streamline the dual catalysis. Transient absorption studies suggest the likelihood of energy transfer activation in the elementary organometallic event. This design strategy is viable to significantly expand the catalytic repertoire of artificial photoenzymes for useful organic transformations.
- Fu, Yu,Huang, Jian,Wu, Yuzhou,Liu, Xiaohong,Zhong, Fangrui,Wang, Jiangyun
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supporting information
p. 617 - 622
(2021/02/03)
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- Method for preparing paraben
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The invention discloses a method for preparing paraben. The method comprises the following steps: adding p-hydroxybenzoic acid (Amol), an alcohol (Bmol) and a benzimidazole ionic liquid (Cmol) into adry three-neck flask, slowly heating, carrying out reflux reaction, and carrying out TLC monitoring until reaction is finished; carrying out reduced pressure distillation to remove a solvent, washingresidues with ethyl acetate, carrying out suction filtration, and carrying out spin-drying on an obtained filtrate to obtain paraben. The yield can reach 90% or above; an obtained filter cake is the benzimidazole ionic liquid and can be recycled; the ratio of A to B to C is 1: 5: (0.2-0.5). The method provided by the invention has the advantages that the catalyst can be recycled, green and environment-friendly effects are realized, the cost is reduced, and the method is an efficient method for synthesizing paraben.
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Paragraph 0025-0028
(2020/03/25)
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- CHEMOSELECTIVE SENSITIVITY BOOSTER FOR TAGGING A PEPTIDE, PEPTIDE CONJUGATE, OR SIMILAR REACTIVE MOLECULE
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The invention pertains to chemoselective sensitivity booster for tagging a peptide, peptide conjugate, or similar reactive molecule for analysis of a peptide, protein, antibody, protein bioconjugate, antibody bioconjugate, and similar analytes. The sensitivity booster comprises of sp2 or sp3 nitrogen centers in combination with hydrophobic carbon chains linked with an electrophile or nucleophile for attachment with a peptide, peptide conjugate, or molecules with similar reactivity.
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Page/Page column 26; 27
(2020/12/29)
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- Design and Structural Optimization of Dual FXR/PPARδActivators
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Nonalcoholic steatohepatitis (NASH) is considered as severe hepatic manifestation of the metabolic syndrome and has alarming global prevalence. The ligand-activated transcription factors farnesoid X receptor (FXR) and peroxisome proliferator-activated receptor (PPAR) δhave been validated as molecular targets to counter NASH. To achieve robust therapeutic efficacy in this multifactorial pathology, combined peripheral PPAR?-mediated activity and hepatic effects of FXR activation appear as a promising multitarget approach. We have designed a minimal dual FXR/PPARδactivator scaffold by rational fusion of pharmacophores derived from selective agonists. Our dual agonist lead compound exhibited weak agonism on FXR and PPARδand was structurally refined to a potent and balanced FXR/PPARδactivator in a computer-aided fashion. The resulting dual FXR/PPARδmodulator comprises high selectivity over related nuclear receptors and activates the two target transcription factors in native cellular settings.
- Schierle, Simone,Neumann, Sebastian,Heitel, Pascal,Willems, Sabine,Kaiser, Astrid,Pollinger, Julius,Merk, Daniel
-
supporting information
p. 8369 - 8379
(2020/08/12)
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- Proline ionic liquid and method for catalyzing synthesis of paraben by proline ionic liquid
-
The invention discloses proline ionic liquid and a method for catalyzing synthesis of paraben by the proline ionic liquid. The preparation method comprises the following steps: adding N-butylbenzimidazole, a solvent and proline into a dry three-neck flask, carrying out reflux reaction until the reaction is complete (monitored by TLC), evaporating to remove the solvent to obtain a faint yellow oilyliquid, namely the proline ionic liquid, adding p-hydroxybenzoic acid, alcohol and a proline ionic liquid into a dry three-necked bottle, heating to reflux reaction, monitoring by TLC until the reaction is finished, evaporating under reduced pressure to remove the solvent, extracting residues with diethyl ether, evaporating the diethyl ether phase to remove the solvent to obtain the methylparabenwith the yield of 88% or above, wherein the remainder is the ionic liquid, and carrying out washing and drying so that the product can be recycled for many times. The method disclosed by the invention is efficient, environment-friendly and safe, the catalyst can be recycled, the cost is reduced, the requirement on equipment is low, and the method is an efficient method for synthesizing paraben.
- -
-
Paragraph 0047-0050
(2020/09/16)
-
- Preclinical evaluation of 1,2,4-triazole-based compounds targeting voltage-gated sodium channels (VGSCs) as promising anticonvulsant drug candidates
-
Epilepsy is a chronic neurological disorder affecting nearly 65–70 million people worldwide. Despite the observed advances in the development of new antiepileptic drugs (AEDs), still about 30–40% of patients cannot achieve a satisfactory seizure control. In our current research, we aimed at using the combined results of radioligand binding experiments, PAMPA-BBB assay and animal experimentations in order to design a group of compounds that exhibit broad spectrum of anticonvulsant activity. The synthesized 4-alkyl-5-substituted-1,2,4-triazole-3-thione derivatives were primarily screened in the maximal electroshock-induced seizure (MES) test in mice. Next, the most promising compounds (17, 22) were investigated in 6 Hz (32 mA) psychomotor seizure model. Protective effect of compound 22 was almost similar to that of levetiracetam. Moreover, these compounds did not induce genotoxic and hemolytic changes in human cells as well as they were characterized by low cellular toxicity. Taking into account the structural requirements for good anticonvulsant activity of 4-alkyl-5-aryl-1,2,4-triazole-3-thiones, it is visible that small electron-withdrawing substituents attached to phenyl ring have beneficial effects both on affinity towards VGSCs and protective activity in the animal models of epilepsy.
- Kaproń, Barbara,?uszczki, Jarogniew J.,Siwek, Agata,Karcz, Tadeusz,Nowak, Gabriel,Zagaja, Miros?aw,Andres-Mach, Marta,Stasi?owicz, Anna,Cielecka-Piontek, Judyta,Kocki, Janusz,Plech, Tomasz
-
-
- Synthesis, characterization, antibacterial evaluation and molecular docking study of 4-{[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenoxy]methyl}benzonitrile derivatives
-
Novel series of 1,3,4-oxadiazole derivatives were synthesized by the reaction between respective acid hydrazides with various aldehydes using chloramine-T (CAT). The structural characterization of compounds 7a-e were confirmed by LC-MS and 1H NMR, 13C NMR spectroscopy and they were subjected for biological evaluation and molecular docking studies. The synthesized compounds exhibited comparable activity with the standard.
- Tc, Krishnaveni,Kotian, Sumana Y.,Abishad,Byrappa,Rai, K. M. Lokanatha
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p. 761 - 765
(2020/12/05)
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- Dual aminoquinolate diarylboron and nickel catalysed metallaphotoredox platform for carbon-oxygen bond construction
-
Herein, aminoquinolate diarylboron complexes are utilized as photocatalysts in dual Ni/photoredox catalyzed carbon-oxygen construction reactions. Via this unified metallaphotoredox platform, diverse (hetero)aryl halides can be conveniently coupled with acids, alcohols and water. This method features operational simplicity, broad substrate scope and good compatibility with functional groups. This journal is
- Day, Craig,Jia, Xin,Wei, Lanfeng,Xu, Liang,Zu, Weisai
-
supporting information
p. 8273 - 8276
(2020/08/17)
-
- A process for preparing Nepal jin zhi method (by machine translation)
-
The invention discloses a method for preparing Nepal jin zhi method: in a reaction container by adding of formula choline chloride (Amol) and methanesulfonic acid (Bmol), for 80 °C stirring to complete dissolution shall be low altogether [...]; cooling to room temperature, then added to the hydroxy benzoic acid of formula (Cmol) acrylic (Dmol), slow heating, reflux reaction, TLC monitoring until a reaction is finished (1 - 2 h); reaction liquid-cooled to the room temperature, precipitate solid, filtered, cake of a small amount of washing, get [...], a yield of 90% or more; recycling the filtrate to obtain low altogether [...]. Wherein A: B: C: D is 1: (1 - 4): 1: (1.1 - 1.5). The method of the invention short reaction time, efficiency is high, the catalyst can be recycled, environmental protection, and reducing the cost; to reduce the consumption of the stinging; low requirements on equipment, is an efficient method of synthesizing [...]. (by machine translation)
- -
-
Paragraph 0035; 0036; 0037; 0038; 0039; 0040; 0041
(2019/10/02)
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- Sensitivity booster for mass detection enables unambiguous analysis of peptides, proteins, antibodies, and protein bioconjugates
-
A chemical tag enhances peptide detection by multiple orders in mass spectrometry. The substantial improvement in the peptide mapping along with simplified and enhanced fragmentation pattern enables the unambiguous sequencing of a protein and antibody. The chemoselective sensitivity booster provides a tool for remarkably improved analysis of protein bioconjugates.
- Singudas, Rohith,Reddy, Neelesh C.,Rai, Vishal
-
supporting information
p. 9979 - 9982
(2019/08/22)
-
- METHOD FOR THE SYNTHESIS AND PURIFICATION OF ARYL ACID ESTERS
-
The general inventive concepts are directed to the discovery that certain aryl acids can be esterified under particular conditions to provide the resulting ester as a solid that precipitates in good yield from the reaction mixture. The esters may then be isolated and purified with relative ease. Accordingly, a method for the esterification, isolation, and purification of aryl acids is provided.
- -
-
Paragraph 0031-0032
(2019/10/17)
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- Targeting malaria and leishmaniasis: Synthesis and pharmacological evaluation of novel pyrazole-1,3,4-oxadiazole hybrids. Part II
-
In continuance with earlier reported work, an extension has been carried out by the same research group. Mulling over the ongoing condition of resistance to existing antimalarial agents, we had reported synthesis and antimalarial activity of certain pyrazole-1,3,4-oxadiazole hybrid compounds. Bearing previous results in mind, our research group ideated to design and synthesize some more derivatives with varied substitutions of acetophenone and hydrazide. Following this, derivatives 5a–r were synthesized and tested for antimalarial efficacy by schizont maturation inhibition assay. Further, depending on the literature support and results of our previous series, certain potent compounds (5f, 5n and 5r) were subjected to Falcipain-2 inhibitory assay. Results obtained for these particular compounds further strengthened our hypothesis. Here, in this series, compound 5f having unsubstituted acetophenone part and a furan moiety linked to oxadiazole ring emerged as the most potent compound and results were found to be comparable to that of the most potent compound (indole bearing) of previous series. Additionally, depending on the available literature, compounds (5a–r) were tested for their antileishmanial potential. Compounds 5a, 5c and 5r demonstrated dose-dependent killing of the promastigotes. Their IC50 values were found to be 33.3 ± 1.68, 40.1 ± 1.0 and 19.0 ± 1.47 μg/mL respectively. These compounds (5a, 5c and 5r) also had effects on amastigote infectivity with IC50 of 44.2 ± 2.72, 66.8 ± 2.05 and 73.1 ± 1.69 μg/mL respectively. Further target validation was done using molecular docking studies. Acute oral toxicity studies for most active compounds were also performed.
- Verma, Garima,Khan, Mohemmed Faraz,Mohan Nainwal, Lalit,Ishaq, Mohd,Akhter, Mymoona,Bakht, Afroz,Anwer, Tariq,Afrin, Farhat,Islamuddin, Mohammad,Husain, Ibraheem,Alam, Mohammad Mumtaz,Shaquiquzzaman, Mohammad
-
-
- Method for preparing parabens
-
The invention discloses a method for preparing parabens. The method comprises the following steps: adding an appropriate amount of methanol (A) into a reaction container, sequentially adding a benzothiazole ionic liquid (B) and p-hydroxybenzoic acid (C) while stirring, slowly heating the obtained solution to a reflux temperature, and carrying out TLC monitoring until the reaction ends; and distilling off methanol, washing the obtained reaction product with ethyl acetate, carrying out suction filtration (the filter cake is the benzothiazole ionic liquid), carrying out rotary evaporation on thefiltrate, washing the product with water, carrying out suction filtration, and drying the product to obtain colorless crystals (methylparaben) at a yield of 91% or above. A ratio of A:B:C is 1:4:0.15, and a catalyst has a high activity and a good stability, and can be recycled. Additionally, the method also has a high esterification rate of 87%% or above to other parabens (ethylparaben, propylparaben, isopropylparaben, butylparaben and n-dodecyl 4-hydroxybenzoate), and provides a good method for industrial synthesis of parabens.
- -
-
Paragraph 0026; 0030-0032; 0048; 0050-0053
(2019/07/01)
-
- Practical heterogeneous photoredox/nickel dual catalysis for C-N and C-O coupling reactions
-
Efficient C-N and C-O coupling reactions of aryl halides with amines and alcohols have been developed by using the strategy of heterogeneous visible light photoredox and nickel dual catalysis. Obviously, the joint use of inexpensive and bench-stable CdS and nickel salts, together with mild reaction conditions, makes these two transformations attractive for the synthetic community. This heterogeneous dual catalysis system also proved to be successful in the ligand-free catalytic hydroxylation of aryl bromide with water as a nucleophile. The practicality of this protocol is further emphasized by the scaled-up reaction and the reusability of heterogeneous photocatalysts.
- Liu, Yi-Yin,Liang, Dong,Lu, Liang-Qiu,Xiao, Wen-Jing
-
supporting information
p. 4853 - 4856
(2019/05/02)
-
- A practical method for preparation of phenols from arylboronic acids catalyzed by iodopovidone in aqueous medium
-
A novel and efficient strategy for the ipso-hydroxylation of arylboronic acids to phenols has been developed using inexpensive, readily available, air-stable water-soluble povidone iodine as catalyst and aqueous hydrogen peroxide as oxidizing agent. The reactions were performed at room temperature under metal-, ligand- and base-free condition in a short reaction time. The corresponding substituted phenols were obtained in moderate to good yields by oxidative hydroxylation of arylboronic acids in aqueous medium.
- Dong, Bin,Ke, Yanxiong,Lu, Guangying,Ren, Jiangmeng,Ren, Yaoyao,Zeng, Bu-Bing,Zhou, Bin
-
-
- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
-
Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
-
supporting information
p. 9472 - 9476
(2019/01/03)
-
- A synthesis method of [...] derivatives (by machine translation)
-
The invention discloses a [...] derivative 4 - (2 - bromine ethoxy group) [...] synthetic method, to the hydroxy benzoic acid as the starting material, through esterification, condensation, reduction, brominated to obtain the target compound, the compound is an important medical intermediates. (by machine translation)
- -
-
Paragraph 0023; 0024
(2018/03/24)
-
- Synthesis of 9,10-Diarylanthracenes via Mg(TMP) 2 ·2LiCl-Mediated Benzyne Generation/[4+2] Cycloaddition and Deoxygenation of 9,10-Epoxyanthracene Intermediates
-
A new synthetic route to functionalized 9,10-diarylanthracenes has been developed. 9,10-Epoxyanthracene intermediates were prepared by [4+2] cycloaddition of 1,3-diarylisobenzofuran with a variety of functionalized benzyne intermediates, which were obtained by Mg(TMP) 2 ·2LiCl-mediated benzyne generation. For the cleavage of the resultant 9,10-epoxyanthracene intermediates, we developed mild deoxygenation conditions using a combination of trifluoroacetic acid and Et 3 SiH. The utility of this sequence was demonstrated by application to the synthesis of 5,7,12,14-tetraphenylpentacene.
- Miyamoto, Naoya,Nakazawa, Yuki,Nakamura, Takanori,Okano, Kentaro,Sato, Sota,Sun, Zhe,Isobe, Hiroyuki,Tokuyama, Hidetoshi
-
supporting information
p. 513 - 518
(2017/12/08)
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- N-(5-Methyl-1,3-Thiazol-2-yl)-2-{[5-((Un)Substituted- Phenyl)1,3,4-Oxadiazol-2-yl]Sulfanyl}acetamides. Unique Biheterocycles as Promising Therapeutic Agents
-
An electrophile, 2-bromo-N-(5-methyl-1,3-thiazol-2-yl)acetamide, was synthesized by the reaction of 5-methyl-1,3-thiazol-2-amine and bromoacetyl bromide in an aqueous medium. In a parallel scheme, a series of (un)substituted benzoic acids was converted sequentially into respective esters, acid hydrazides, and then into 1,3,4-oxadiazole heterocyclic cores. The electrophile was coupled with the aforementioned 1,3,4-oxadiazoles to obtain the targeted bi-heterocyles. Structural analysis of the synthesized compounds was performed by IR, EI-MS, 1H NMR, and 13C NMR. The enzyme inhibition study of these molecules was carried out against four enzymes, namely, acetylcholinesterase, butyrylcholinesterase, α-glucosidase, and urease. The interactions of these compounds with respective enzymes were recognized by their in silico study. Moreover, their cytotoxicity was also determined to find out their utility as possible therapeutic agents.
- Abbasi,Ramzan,Aziz-ur-Rehman,Siddiqui,Shah,Hassan,Seo,Ashraf,Mirza,Ismail
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p. 801 - 811
(2019/02/27)
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- Synthesis of Hydroxybenzoic Acids and Their Esters by Reaction of Phenols with Carbon Tetrachloride and Alcohols in the Presence of Iron Catalysts
-
Alkyl esters of hydroxy-, methoxy-, and ethoxybenzoic and cresotic acids have been synthesized by reaction of phenols, anisole, phenetole, and cresols with carbon tetrachloride and alcohols in the presence of iron catalysts.
- Bayguzina,Tarisova,Khusnutdinov
-
p. 208 - 215
(2018/03/26)
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- Pd-Catalyzed debenzylation and deallylation of ethers and esters with sodium hydride
-
Herein we demonstrate simply that the addition of Pd(OAc)2 as a promotor switches the reactivity of a commonly used base NaH to a nucleophilic reductant. The reactivity is engineered into a palladium-catalyzed reductive debenzylation and deallylation of aryl ethers and esters. This operationally simple, mild protocol displays a broad substrate scope and a broad spectrum of functional group tolerance (>50 examples) and high chemoselectivity toward aryl ethers over aliphatic structures. Moreover, the dual reactivity of NaH as a base and a reductant is demonstrated in efficient synthetic elaboration.
- Mao, Yujian,Liu, Ye,Hu, Yanwei,Wang, Liang,Zhang, Shilei,Wang, Wei
-
p. 3016 - 3020
(2018/04/14)
-
- Application of metallide/palladium compound catalytic reduction system in debenzylation reaction and deuterization reaction
-
The invention discloses an application of a metallide/palladium compound catalytic reduction system in debenzylation reaction and deuterization reaction of benzyl-containing compounds. The reaction comprises the following steps: under the protection of nitrogen, suspending a palladium compound and a metallide in a solvent, stirring for 5 minutes, adding the benzyl-containing compounds, carrying out a reaction for 0.5 to 48 h at the temperature of -30 DEG C to 150 DEG C, adding ice water to stop the reaction, adjusting the pH value to 3.5 with diluted hydrochloric acid, extracting the reactionsolution by a solvent, drying by distillation, purifying by column chromatography, and thus completing the reaction.
- -
-
Paragraph 0043
(2018/09/08)
-
- Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
-
The alkylation of carboxylic acids by an ethyl moiety of boron trifluoride etherate in the absence of ethyl alcohol from the reaction system is unexpected and novel. Both aromatic and aliphatic carboxylic acids were clearly alkylated affording good yields in short reaction times with the exception of nicotinic acid that necessitated an overnight reaction. It was noted that while ortho-substituted hydroxyl groups of carboxylic acids investigated were not affected by alkylation, those of meta- and para-substituted carboxylic acids were partially etherified. Furthermore, the alkylation reaction was found to be compatible with a range of functional groups such as halogens, amino and nitro groups except for the alkene function of undecylenic acid that underwent polymerisation with concomitant alkylation of its carboxylic acid function.
- Jumbam, Ndze D.,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
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p. 387 - 392
(2018/09/06)
-
- Palladium-Catalyzed Aerobic Oxidative Carbonylation of C–H Bonds in Phenols for the Synthesis of p-Hydroxybenzoates
-
This work reports the synthesis of p-hydroxybenzoates directly from phenols by oxidative carbonylation of phenolic C–H bonds, proceding through oxidative iodination. The developed methodology is efficient and economically attractive because phenols are cheap and easily available starting materials. This one-pot strategy was expediently applied to the synthesis of a variety of p-hydroxybenzoates by utilizing simple primary and secondary alcohols with different phenols under mild reaction conditions. Advantageously, the procedure has no need for co-catalysts, co-solvents or external ligands. The utilization of molecular oxygen as a terminal oxidant for C–H bond oxidation represents an additional benefit.
- Gaikwad, Vinayak V.,Bhanage, Bhalchandra M.
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p. 2877 - 2881
(2018/06/21)
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- Synthesis of Phenols: Organophotoredox/Nickel Dual Catalytic Hydroxylation of Aryl Halides with Water
-
A highly effective hydroxylation reaction of aryl halides with water under synergistic organophotoredox and nickel catalysis is reported. The OH group of the resulting phenols originates from water, following deprotonation facilitated by an intramolecular base group on the ligand. Significantly, aryl bromides as well as less reactive aryl chlorides served as effective substrates to afford phenols with a wide range of functional groups. Without the need for a strong inorganic base or an expensive noble-metal catalyst, this process can be applied to the efficient preparation of diverse phenols and enables the hydroxylation of multifunctional pharmaceutically relevant aryl halides.
- Yang, Liu,Huang, Zhiyan,Li, Gang,Zhang, Wei,Cao, Rui,Wang, Chao,Xiao, Jianliang,Xue, Dong
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supporting information
p. 1968 - 1972
(2018/02/06)
-
- Fe-catalyzed esterification of amides via C-N bond activation
-
An efficient Fe-catalyzed esterification of primary, secondary, and tertiary amides with various alcohols for the preparation of esters was performed. The esterification process was accomplished with FeCl3$6H2O, which is a stable, inexpensive, environmentally friendly catalyst with high functional group tolerance.
- Chen, Xiuling,Hu, Siying,Chen, Rongxing,Wang, Jian,Wu, Minghu,Guo, Haibin,Sun, Shaofa
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p. 4571 - 4576
(2018/02/09)
-
- Efficient dealkylation of aryl alkyl ethers catalyzed by Cu2O
-
An efficient protocol for dealkylation of aryl alkyl ethers under the catalysis of inexpensive and easily reusable Cu2O has been described. The phenol products were obtained in high yields, and a range of functional groups were well tolerated. The choice of solvent is critical to the catalysis, and CH3OH proved to be the optimal choice. Mechanistic investigations showed that this reaction possibly proceeds via a single-electron transfer (SET) process.
- Liu, Lingxian,Li, Zengguang,Chen, Changjun,Li, Huanrong,Xu, Lijin,Yu, Zhiyong
-
supporting information
p. 2447 - 2453
(2018/04/11)
-
- Design and optimization of N-acylhydrazone pyrimidine derivatives as E. coli PDHc E1 inhibitors: Structure-activity relationship analysis, biological evaluation and molecular docking study
-
By targeting the thiamin diphosphate (ThDP) binding site of Escherichia coli (E. coli) pyruvate dehydrogenase multienzyme complex E1 (PDHc E1), a series of novel ‘open-chain’ classes of ThDP analogs A, B, and C with N-acylhydrazone moieties was designed and synthesized to explore their activities against E. coli PHDc E1 in vitro and their inhibitory activity against microbial diseases were further evaluated in vivo. As a result, A1–23 exhibited moderate to potent inhibitory activities against E. coli PDHc E1 (IC50 = 0.15–23.55 μM). The potent inhibitors A13, A14, A15, C2, had strong inhibitory activities with IC50 values of 0.60, 0.15, 0.39 and 0.34 μM against E. coli PDHc E1 and with good enzyme-selective inhibition between microorganisms and mammals. Especially, the most powerful inhibitor A14 could 99.37% control Xanthimonas oryzae pv. Oryzae. Furthermore, the binding features of compound A14 within E. coli PDHc E1 were investigated to provide useful insights for the further construction of new inhibitor by molecular docking, site-directed mutagenesis, and enzymatic assays. The results indicated that A14 had most powerful inhibition against E. coli PDHc E1 due to the establishment of stronger interaction with Glu571, Met194, Glu522, Leu264 and Phe602 at active site of E.coli PDHc E1. It could be used as a lead compound for further optimization, and may have potential as a new microbicide.
- He, Haifeng,Xia, Hongying,Xia, Qin,Ren, Yanliang,He, Hongwu
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p. 5652 - 5661
(2017/10/09)
-
- New Biguanides as Anti-Diabetic Agents, Part II: Synthesis and Anti-Diabetic Properties Evaluation of 1-Arylamidebiguanide Derivatives as Agents of Insulin Resistant Type II Diabetes
-
New 1-arylamidebiguanide hydrochloride salts were synthesized via reaction of hydrazide derivatives with dicyandiamide in acidic medium. The structure of the obtained derivatives was characterized by spectroscopic and elemental analysis tools. The anti-diabetic properties of the synthesized compounds were determined. Oral treatment of hyperglycemic rats with the synthesized biguanide derivatives showed a significant decrease of the elevated glucose in comparison with the anti-diabetic standard drug, metformin. The effects of the synthesized biguanide derivatives on the diabetic properties regarding liver function enzyme activities (AST, ALT, and ALP), lipid profiles (TC, TG, and TL), lipid peroxide, and nitrous oxide as well as histopathological characteristics were investigated and discussed.
- Basyouni, Wahid M.,Abbas, Samir Y.,El Shehry, Mohamed F.,El-Bayouki, Khairy A.M.,Aly, Hanan F.,Arafa, Azza,Soliman, Mahmoud S.
-
-
- Synthesis and pharmacological screening: Sulfa derivatives of 2-pipecoline-bearing 1,3,4-oxadiazole core
-
An electrophile, 1-(4-(bromomethylbenzenesulfonyl)-2-methylpiperidine, was synthesized by the reaction of 2-methylpiperidine (2-pipecoline) and 4-bromomethylbenzenesulfonyl chloride in a weak basic medium under pH control. A series of nucleophiles, 5-aryl/aralkyl-1,3,4-oxadiazol-2-thiols, were synthesized from corresponding carboxylic acids in three steps. The title molecules were synthesized by coupling the electrophile to nucleophiles in an aprotic medium using LiH as an activator. The structures of all synthesized compounds were corroborated through IR, 1H NMR, and EI-MS techniques. All the compounds were screened for their pharmacological behavior, particularly, antibacterial and enzyme inhibitory activities. Notably efficient results were obtained against both gram-positive and gram-negative bacterial strains. Regarding enzyme inhibition, compounds were efficient against acetylcholinesterase and butyrylcholinesterase.
- Aziz-ur-Rehman,Arif,Abbasi,Siddiqui,Rasool,Shah
-
p. 328 - 339
(2017/07/04)
-
- Synthetic method of 4-chlorotoluene compound
-
The invention discloses a synthetic method of a 4-chlorotoluene compound 4-(2-chloroethoxy) benzyl chloride. According to the synthetic method, p-hydroxybenzoic acid is taken as an initial raw material, and the target compound is obtained via esterification, condensation, reduction, and chlorination. The target compound is an important pharmaceutical intermediate.
- -
-
Paragraph 0023; 0024
(2017/07/20)
-
- Synthesis of Complex Phenols Enabled by a Rationally Designed Hydroxide Surrogate
-
The conversion of aryl halides to phenols under mild reaction conditions is a longstanding and formidable challenge in organic chemistry. Herein, we report the rational design of a broadly applicable Pd-catalyzed method to prepare phenols with benzaldehyde oxime as a hydroxide surrogate. These reactions occur under mildly basic conditions and enable the late-stage hydroxylation of several functionally-dense drug-like aryl halides.
- Fier, Patrick S.,Maloney, Kevin M.
-
supporting information
p. 4478 - 4482
(2017/04/13)
-
- Reagent Design and Ligand Evolution for the Development of a Mild Copper-Catalyzed Hydroxylation Reaction
-
Parallel synthesis and mass-directed purification of a modular ligand library, high-throughput experimentation, and rational ligand evolution have led to a novel copper catalyst for the synthesis of phenols with a traceless hydroxide surrogate. The mild reaction conditions reported here enable the late-stage synthesis of numerous complex, druglike phenols.
- Fier, Patrick S.,Maloney, Kevin M.
-
supporting information
p. 3033 - 3036
(2017/06/07)
-
- Preparation method of N-methyl-4-hydroxybenzamide
-
The invention relates to a preparation method of N-methyl-4-hydroxybenzamide, wherein the preparation method comprises the following steps: 1) adding 4-hydroxybenzoyl chloride and triethylamine into a container, heating under stirring to make the system temperature be 20-50 DEG C, then dropping absolute ethyl alcohol with the dropping time of 0.5-1 h, after the dropping is finished, carrying out a heat preservation reaction for 2-5 h at the temperature of 20-50 DEG C, then carrying out suction filtration of the reaction liquid to remove triethylamine hydrochloride, and thus obtaining a filtrate, namely ethyl 4-hydroxybenzoate; and 2) adding ethyl 4-hydroxybenzoate into the container, stirring and heating to 30-60 DEG C, dropping methylamine with the dropping time of 0.5-1 h, after the dropping is finished, carrying out a heat preservation reaction for 3-5 h at the temperature of 30-60 DEG C, cooling to room temperature, precipitating out a large number of solids, and carrying out suction filtration, to obtain a filter cake, namely N-methyl-4-hydroxybenzamide. Compared with the prior art, with adopting of the stepwise reaction, the yield of N-methyl-4-hydroxybenzamide is greatly improved.
- -
-
Paragraph 0021; 0024; 0027; 0030; 0033; 0036
(2017/07/01)
-
- A Ni-Mg-Al layered triple hydroxide-supported Pd catalyst for heterogeneous acceptorless dehydrogenative aromatization
-
In the presence of a Ni-Mg-Al layered triple hydroxide-supported Pd catalyst, the acceptorless dehydrogenative aromatization of a wide range of cyclohexanols/cyclohexanones and cyclohexylamines efficiently proceeded to give the corresponding phenols and anilines, respectively, in moderate to high yields with the liberation of molecular hydrogen.
- Jin, Xiongjie,Taniguchi, Kento,Yamaguchi, Kazuya,Nozaki, Kyoko,Mizuno, Noritaka
-
supporting information
p. 5267 - 5270
(2017/07/10)
-
- N-Substituted 3(10H)-Acridones as Visible-Light, Water-Soluble Photocatalysts: Aerobic Oxidative Hydroxylation of Arylboronic Acids
-
We disclosed a novel water-soluble photocatalyst that could promote aerobic oxidative hydroxylation of arylboronic acids to furnish phenols in excellent yields. This transformation uses visible-light irradiation under environmentally friendly conditions, that is, water-soluble catalyst, metal-free, green oxidant, room temperature.
- Xie, Hong-Yan,Han, Li-Shuai,Huang, Shan,Lei, Xiantao,Cheng, Yong,Zhao, Wenfeng,Sun, Hongbin,Wen, Xiaoan,Xu, Qing-Long
-
p. 5236 - 5241
(2017/05/24)
-
