- Solvatochromic behavior of a pyrene-pyrimidine-based Schiff base and detection of heavy metal ions in aqueous media
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The synthesis and solvatochromic behavior of pyrimidine based Schiff-base (PYPH) were studied to develop a fluorescent chemo sensor for the detection of Hg2+ in aqueous solution. The characterization of PYPH was investigated on the basis of UV–vis, FTIR, 1H-NMR and mass spectral data. PYPH displays selective fluorescent turn-off response to Hg2+ in aqueous solution. The sensitivity and selectivity of PYPH toward Hg2+ among different metal ions was examined by absorption, fluorescence, 1H-NMR and mass spectral studies. Binding stoichiometry (2:1) has been confirmed by a Job’s plot, HRMS spectral studies and 1H-NMR analysis. A low detection limit was 4.2 × 10?6 M for Hg2+. Ground state geometry of PYPH has been optimized using density functional theory (DFT). These results demonstrate that PYPH has promise to detect Hg2+ ion in environmental analysis systems.
- Ghosh, Swadesh,Singharoy, Dipti,Konar, Saugata,Naskar, Jnan Prakash,Bhattacharya, Subhash Chandra
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- Nonionic Surfactants as Potential Carriers of a Synthesized Pyrimidine Derivative: Spectroscopic and Quantum Chemical Investigations
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Currently, a major problem is the poor water solubility and bioavailability of many pharmaceuticals. Using different types of surfactants is an effective strategy to overcome this problem. Herein a pyrimidine-based Schiff base, 2-[2-(anthracen-9-ylmethylene) hydrazinyl]-4,6-dimethyl pyrimidine (ANHP), has been synthesized and characterized by different spectroscopic methods. A comparative study of drug carrier properties of cationic, anionic, and the nonionic surfactants with this pyrimidine derivative (ANHP) in aqueous solution is the key research interest of this work. From fluorescence studies, the interaction of ANHP with the different types of surfactants were compared and binding constants of ANHP in vesicles were determined. The drug carrier properties of different surfactants were investigated by using different spectroscopic techniques. DLS, zeta potential, and AFM studies have shown that in the presence of ANHP, nonionic surfactants take a vesicular shape. Several experimental results clearly indicate that Ig-720 is the better choice as ANHP carrier among all the surfactants investigated. In addition, the structure of ANHP has been optimized by density functional theory (DFT). The theoretical and experimental results have been compared.
- Ghosh, Swadesh,Singharoy, Dipti,Dhara, Anamika,Naskar, Jnan Prakash,Bhattacharya, Subhash Chandra
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- Electrochemical-induced hydroxylation of aryl halides in the presence of Et3N in water
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A thorough study of mild and environmentally friendly electrochemical-induced hydroxylation of aryl halides without a catalyst is presented. The best protocol consists of hydroxylation of different aryl iodides and aryl bromides by water solution in the presence of Et3N under air, affording the target phenols in good isolated yields. Moreover, aryl chlorides were successfully employed as substrates. This methodology also provides a direct pathway for the formation of deoxyphomalone, which displayed a significant anti-proliferation effect.
- Ke, Fang,Lin, Chen,Lin, Mei,Long, Hua,Wu, Mei,Yang, Li,Zhuang, Qinglong
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supporting information
p. 6417 - 6421
(2021/08/03)
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- Method for synthesizing phenol or derivative thereof in aqueous phase by photocatalytic one-pot method
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The invention discloses a method for synthesizing phenol or a derivative thereof in an aqueous phase by a photocatalytic one-pot method. The method comprises the following steps: by taking a compoundaryl halide shown in formula (I) as a raw material and water as a solvent, adding a catalyst and an auxiliary agent, and carrying out reacting under the conditions of alkali and visible light to obtain the phenol or the derivative (II) thereof. Compared with the prior art, the method is applicable to a large number of functional groups, high in yield, few in byproducts, simple and safe to operate,low in cost and environmentally friendly, wherein R is selected from substituted or non-substituted phenyl, pyridyl, quinolyl or pyrimidinyl; X is selected from halogen; the substituted phenyl is substituted by C1-C4 alkyl, C1-C4 alkoxy, hydroxyl, halogen, cyano, aldehyde group, nitro, amino, acetyl or carboxyl; and the substituted pyridyl, quinolyl or pyrimidinyl is pyridyl, quinolyl or pyrimidinyl substituted by C1-C4 alkyl.
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Paragraph 0032-0033; 0079-0080; 0085-0106
(2020/12/08)
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- Process Research for (+)-Ambrisentan, an Endothelin-A Receptor Antagonist
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An efficient and robust synthetic route to (+)-ambrisentan ((+)-AMB) was designed by recycling the unwanted isomer from the resolution mother liquors. The racemization of AMB in the absence of either acid or base in the given solvents was reported. The recovery process was developed to produce racemates with purities over 99.5%. The mechanism of the formation of the process-related impurities of (+)-AMB is also discussed in detail. (+)-AMB was obtained in 47% overall yield with >99.5% purity and 99.8% e.e. by chiral resolution with only one recycling of the mother liquors on a 100-g scale without column purification.
- Feng, Wei-Dong,Zhuo, Song-Ming,Yu, Jun,Zhao, Chuan-Meng,Zhang, Fu-Li
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p. 1200 - 1207
(2018/09/06)
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- Microwave-assisted copper-catalyzed hydroxylation of aryl halides in water
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A simple and efficient protocol for microwave-assisted copper-catalyzed hydroxylation of aryl halides is developed. A variety of phenols can be obtained in moderate to excellent yields of up to 95%. Its application is performed to synthesize 2,3-dihydroxy-1,4-naphthoquinone, which displays significant anti-proliferation effect.
- Ke, Fang,Chen, Xiaole,Li, Zhengkai,Xiang, Haifeng,Zhou, Xiangge
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p. 22837 - 22840
(2013/11/19)
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- NEW POSITIVE ALLOSTERIC MODULATORS OF NICOTINIC ACETYLCHOLINE RECEPTOR
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The present invention relates to compounds useful in therapy, to compositions comprising said compounds, and to methods of treating diseases comprising administration of said compounds. The compounds referred to are positive allosteric modulators (PAMs) of the nicotinic acetylcholine alpha7 receptor.
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Page/Page column 12
(2013/02/28)
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- PYRAZOLOPYRIDINES USEFUL IN THE TREATMENT OF DISORDERS OF THE CENTRAL NERVOUS SYSTEM
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The present invention relates to compounds useful in therapy, to compositions comprising said compounds, and to methods of treating diseases comprising administration of said com- pounds. The compounds referred to are positive allosteric modulators (PAMs) of the nicotinic acetylcholine α7 receptor.
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Page/Page column 30
(2013/03/26)
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- Nitrogen-containing heterocycles from metal β-diketonates
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Factors determining the reaction of metal β-diketonates with hydrazine, in particular the nature of central metal ion and structure of β-diketonate ligand, are discussed. The possibility for the preparation of other heterocyclic compounds via reaction of metal acetylacetonates with phenylhydrazine, o-phenylenediamine, urea, and thiourea was studied.
- Svistunova,Shapkin,Nikolaeva,Apanasenko
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experimental part
p. 756 - 761
(2011/08/06)
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- Microwave-expedited one-pot, two-component, solvent-free synthesis of functionalized pyrimidines
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The synthesis of a series of diversely substituted pyrimidines under solvent-free conditions in good yields is described. Under microwave irradiation, a variety of nucleophilic substrates containing the N?C?N unit with ?-dicarbonyl compounds, ethyl cyanoacetate, malononitrile, and chalcones was cyclized to give pyrimidines. A combinatorial type approach for a one-step synthesis has been developed where a ring-closing condensation is followed by spontaneous aromatization to afford 28 functionalized and aryl/alkyl substituted pyrimidines. CSIRO 2007.
- Goswami, Shyamaprosad,Jana, Subrata,Dey, Swapan,Kumar Adak, Avijit
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p. 120 - 123
(2008/02/11)
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- Reaction of pyrimidyl esters of some phosphorus acids with isomeric butyl alcohols
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A series of pyrimidyl esters of some phosphorus acids was prepared with the purpose of investigation of their reaction with isomeric butyl alcohols. According to31P NMR data, the obtained phosphates all are capable of phosphorylating isomeric butyl alcohols. The reactions with diphenyl (4-oxo-3,4-dihydro-2-pyrimidyl) phosphate and diphenyl (2-pyrimidyl) phosphate occur in quantitative yield under mild conditions, and the reactions with diphenyl (4,6-dimethyl-2-pyrimidyl) phosphate and dibutyl (4,6-dimethyl-2-pyrimidyl) phosphate require severe conditions to occur. In the latter two cases, certain reaction selectivity was observed, depending on the nature of the solvent and some other factors. Pyrimidyl esters of sulfur-containing phosphorus acids do not react with isomeric butyl alcohols under the studied conditions.
- Semenov,Akamsin,Enikeev,Reznik
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p. 1386 - 1388
(2007/10/03)
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- Fungal and bacterial regioselective hydroxylation of pyrimidine heterocycles
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The bacterium Rhodococcus erythropolis is employed to hydroxylate the anxiolytic lesopitron, and this bacterium, together with Agrobacterium sp. and the fungus Beauveria bassiana, are used to extend the field of hydroxylation of heteroaromatic compounds to a series of unexplored pyrimidines. Of all the substrates investigated, only the carbamate 11a is regioselectively hydroxylated by B. bassiana at the C-5 position of the pyrimidine ring; in contrast, the bacteria are able to regioselectively oxidize, when free, the C-2 and/or C-4 positions of the pyrimidine moiety of all the substrates 1a - 12a up to a maximum of two oxidations.
- Gotor, Vicente,Quiros, Margarita,Ramon, Liz,Frigola, Jordi,Fernandez, Rosa
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p. 6421 - 6432
(2007/10/03)
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- β-Diketone Interactions. Part 11. The Hydrogen-bonded Adduct 4,6-Dimethylpyrimidin-2-one*Urea (DMP*U) from the Reaction of Pentane-2,4-dione and Urea
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The X-ray crystal structure of the adduct formed between 4,6-dimethylpyrimdin-2-one and urea (DMP*U) shows a compact unit joined through two N-H...O=C hydrogen bonds.One of these is remarkably short with RN...O 2.735 Angstroem (RH...O 1.705 Angstroem), and is believed to be among the shortest example of an NHO hydrogen bond between neutral molecules.Its hydrogen-bond energy, estimated from IR data, is ca. 75 kJ mol-1.
- Emsley, John,Ma, Lewina Y. Y.,Hursthouse, Michael B.,Karaulov, Sacha A.,Motevalli, Majid
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p. 1077 - 1080
(2007/10/02)
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- SYNTHESIS OF SUBSTITUTED METHYL ARYL KETONE PYRIMIDINYLOXIMES AND THEIR REACTIONS WITH NUCLEOPHILES
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Chloropyrimidines react readily with the sodium salts of alkyl aryl ketoximes to give acetophenone O-(2,4-dimethylpyrimidin-6-yl)- and O-(4,6-dimethylpyrimidin-2-yl)oximes, the oximino-groups in which readily undergo nucleophilic substitution.
- Danagulyan, G. G.,Balasanyan, N. G.,Terent'ev, P. B.,Zalinyan, M. G.
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p. 1369 - 1373
(2007/10/02)
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- A C-13 nuclear magnetic resonance study of the pyrimidine synthesis by the reactions of 1,3-dicarbonyl compounds with amidines and ureas
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The detailed mechanistic pathways are elucidated for the reactions of acetylacetone, methyl acetoacetate, and dimethyl malonate with a variety of amidines and ureas.In many cases the identification of a single intermediate allows the definition of the reaction path and identification of two steps.Intermediates characterized include ring-closed dihydroxytetrahydropyrimidines, dihydrohydroxypyrimidinones, open-chain enamides, and carbonyl addition compounds.
- Katritzky, Alan R.,Yousaf, Taher I.
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p. 2087 - 2093
(2007/10/02)
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- SYNTHESIS OF SUBSTITUTED 2- AND 4-HYDROXYAMINOPYRIMIDINES
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The reaction of 2- and 4-chlorine-containing alkyl(aryl)pyrimidines with hydroxylamine was studied.It was shown that, depending on the amount of hydroxylamine , N,O-dipyrimidinylhydroxyamides or the corresponding 2- and 4-hydroxyaminopyrimidines are formed together with 2- and 4-oxodihydropyrimidines.
- Moskalenko, G. G.,Sedova, V. F..,Mamaev, V. P.
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p. 1232 - 1236
(2007/10/02)
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- Nucleophilic Displacements of N-Aryl and Heteroaryl Groups. Part 4. Pyrylium-mediated Transformations of Heteroarylamines into Pyridinium Salts and their Inter- and Intra-molecular Displacement
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Heteroarylamines and the appropriate pyrylium salts give 1-heteroaryl-2-ethoxycarbonyl-4,6-diphenylpyridinium, and 1-(2-pyridyl)-2,6-diethoxycarbonyl-4-phenylpyridinium salts.Hydrolysis and decarboxylation afford 1-(2-pyridyl)-2,4-diphenyl- and 1-(2-pyridyl)-4-phenyl-pyridinium salts.Neither these, nor their 2,4,6-triphenyl analogues underwent smooth nucleophilic substitution. 1-Pyrimidin-2-yl- and 1-(4,6-dimethylpyrimidin-2-yl)-2-ethoxycarbonyl-4,6-diphenylpyridinium with ethanolic NaOEt smoothly formed the corresponding pyrimidin-2-ones via intramolecular attack.
- Katritzky Alan R.,Agha, Bushra J.,Awartani, Radi,Patel, Ranjan C.
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p. 2617 - 2621
(2007/10/02)
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- Kinetic Study of the Acid-Promoted Hydrolysis of Some Representative 2-Fluoro Nitrogen Heterocycles
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The acid-promoted hydrolysis of the 2-fluoro derivatives of pyridine, the four isomeric picolines, quinoline, pyrimidine, 4-methylpyrimidine, and 4,6-dimethylpyrimidine have been studied in hydrochloric acid over the concentration range of 0.05-8.0 F HCl.At each acid concentration, the reactions followed pseudo-first-order kinetics, and at low concentrations of acid, the rate of reaction increased linearly with h0.However, at higher acid concentrations negative deviations from linearity were observed for all the substrates and rate maxima for all but the pyrimidines.These results were correlated with the decline in water activity by means of the Bunnett ω and ω* relationships, as well as the Bunnett-Olsen LFER.The slopes of these correlations were suggestive of a proton transfer role for water in the reactions of the less activated 2-fluoropyridines and of 2-fluoroquinoline, while the correlations indicate a nucleophilic role for water in the reactions of the more highly activated pyrimidines.Entropies of activation, calculated both from the pseudo-first-order rate constants, and from the values of k2* obtained from the intercepts of the LFER plot, were significantly more negative for the pyridine and quinoline systems for the pyrimidines.The above results are interpreted as consistent with nucleophilic attack by water in the rate-determining step for the reaction of the pyrimidines, while for the less activated substrates nucleophilic attack may be assisted by proton transfer to additional water molecules.
- Clark, H. R.,Beth, L. D.,Burton, R. M.,Garrett, D. L.,Miller, A. L.,Muscio, O. J.
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p. 4363 - 4369
(2007/10/02)
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