- Palladium-Catalyzed Cyanation under Mild Conditions: A Case Study to Discover Appropriate Substrates among Halides and Pseudohalides
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A case study has been effectively carried out to identify a suitable substrate among halides and pseudohalides for the palladium-catalyzed cyanation reactions under mild conditions. Among the various substrates considered for evaluation, aryl pentafluorobenzenesulfonates and nonaflates were identified to be the best substrates when compared to corresponding halides and pseudohalides. The substoichiometric use of nontoxic, environmentally benign potassium hexacyanoferrate as a cyanide source and exceptionally milder conditions further highlights the significance of the protocol developed. A wide range of electronically biased and sterically challenging substrates provided the corresponding the nitriles in good to excellent yields.
- Rajendra, Merla Arjuna,Sunil,Sajith, Ayyiliath Meleveetil,Joy, Muthipeedika Nibin,Bakulev, Vasiliy A.,Haridas, Karickal Raman
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supporting information
p. 1629 - 1633
(2020/09/15)
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- Palladium-Catalyzed Cyanation of Aryl Halides Using Formamide and Cyanuric Chloride as a New “CN” Source
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A new source of “CN” employing formamide and cyanuric chloride is introduced for the cyanation reactions. The treatment of formamide and 2,4,6-trichloro-1,3,5-triazine (TCT; cyanuric chloride) afforded an efficient cyanating agent which it can be used as a nontoxic, readily available, and non-expensive reagent in the cyanation transformations. In this study, palladium-catalyzed cyanation of aryl halides was successfully accomplished using this new “CN” source in high yields.
- Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
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p. 2699 - 2707
(2020/04/08)
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- Method for synthesizing 4 - chlorine -3 - nitrotoluene carbonitrile by using microchannel reactor (by machine translation)
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4 -chlorobenzonitrile is dissolved in an organic solvent -3 - to obtain 4 -chlorobenzonitrile solution, and 1 chlorobenzonitrile solution and nitric acid and sulfuric acid mixed acid are respectively introduced into the microchannel reactor to react and then enter into the enhanced mass transfer module and the direct flow micro-channel module to obtain solid and dry matter after being washed to obtain 4 - 4 - chlorine -3 - 4 - nitrobenzonitrile. The method has the advantages of simple operation, mild reaction conditions, rapid reaction, high yield, continuous production and the like, solves the safety problem of nitration reaction, and is high in practicability; and the synthesized 4 - chlorine -3 - nitrotoluene carbonitrile is particularly suitable as an intermediate for preparing asatinib hydrochloride. (by machine translation)
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Paragraph 0023-0066
(2020/12/09)
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- Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS): An efficient catalyst for cyanation reaction in aqueous media
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Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS) were found to be an efficient heterogeneous catalyst in the cyanation reaction of aryl halides in aqueous media. This catalyst system is containing palladium nanoparticles with a size of ~7 nm. Moreover, the CD-PU-NS support formed microsphere-shaped structures with a size of ~100–200 nm. The TEM images show that Pd nanoparticles were formed in near spherical shape morphology and were immobilized in the structure of the CD-PU-NS support. Under our optimized reaction conditions, aryl cyanides were obtained in high yields in the presence of the Pd-CD-PU-NS catalyst. Our results demonstrated that the Pd-CD-PU-NS catalyst is highly effective in the cyanation reaction in aqueous media. Furthermore, the catalyst could be simply extracted from the reaction mixture, providing an efficient methodology for the synthesis of aryl cyanides. The Pd-CD-PU-NS catalyst could be recycled four times with almost consistent catalytic efficiency.
- Khajeh Dangolani, Soheila,Sharifat, Sara,Panahi, Farhad,Khalafi-Nezhad, Ali
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supporting information
p. 256 - 265
(2019/06/07)
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- Development of highly active anti-: Pneumocystis bisbenzamidines: Insight into the influence of selected substituents on the in vitro activity
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Here we describe the potency of 21 pentamidine analogues against the fungal pathogen, Pneumocystis carinii, in an ATP bioluminescent assay with toxicity profiles in 2 mammalian cell lines. Reduction of two 5-methyl-1,2,4-oxadiazole rings was applied to the synthesis of acid-labile bisamidines. Anti-Pneumocystis activity is discussed in the context of 3 groups of compounds depending on the main structural changes of the pentamidine lead structure. The groups include: 1) 1,4-bis(methylene)piperazine derivatives 1-5; 2) alkanediamide derivatives 6-10; 3) alkane-derived bisbenzamidines 11-21. IC50 values of 18 compounds were lower than the IC50 of pentamidine. Four bisamidines were active at nanogram concentrations. Introduction of sulfur atoms in the alkane bridge, replacement of the amidino groups with imidazoline rings, or attachment of nitro or amino groups to the benzene rings is responsible for remarkable activity of the new leading structures. The vast majority of compounds, including four highly active ones, can be classified as mild or nontoxic to host cells. These compounds show promise as candidates for new anti-Pneumocystis agents.
- Maciejewska,Zabiński,Rezler,Ka?mierczak,Collins,Ficker,Cushion
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p. 2003 - 2011
(2017/10/27)
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- Research on controllable degradation of sulfonylurea herbicides
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In order to seek ecologically safer and environmentally benign sulfonylurea herbicides (SU), insight into the structure/bioassay/soil degradation tri-factor relationship was first established. With the introduction of various groups (alkyl, nitro, halogen, cyano etc.) at the 5th position of its benzene ring, structural derivatives of chlorsulfuron were designed, synthesized, and evaluated for their herbicidal activity. The structures of the title compounds were confirmed by infrared spectroscopy, ultraviolet spectroscopy, 1H and 13C NMR, mass spectrometry, elemental analysis and X-ray diffraction. Bioassay results confirmed that most derivatives retained their superior herbicidal activities in comparison with chlorsulfuron. After investigating the soil degradation behavior of each molecule under set conditions, it was found that structures with electron-withdrawing substituents at the 5th position of the benzene ring retained their long degradation half-lives, yet the introduction of electron-donating substituents accelerated the degradation rate. These results will provide a valuable clue to further explore the potential controllable degradation of SU and other herbicides, and to discover novel herbicides that are favorable for environmentally and ecologically sustainable development.
- Hua, Xue-Wen,Chen, Ming-Gui,Zhou, Shaa,Zhang, Dong-Kai,Liu, Ming,Zhou, Sha,Liu, Jing-Bo,Lei, Kang,Song, Hai-Bin,Li, Yong-Hong,Gu, Yu-Cheng,Li, Zheng-Ming
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p. 23038 - 23047
(2016/03/12)
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- PYRROLIDINE DERIVATIVES WITH ANTIBACTERIAL PROPERTIES
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Provided is a compound of Formula (I) or a salt thereof: Formula (I) wherein R, m, n, R1, R2, Aa-Ac are defined as in the claims and ArI represents a bicyclic heterocyclic group of the following formula: Formula (2) Ar 2 represents a bicyclic heterocyclic group of the formula: [Formula 3] having antibacterial activity.
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Page/Page column 40
(2014/03/21)
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- BENZIMIDAZOLES AS FATTY ACID SYNTHASE INHIBITORS
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This invention relates to the use of benzimidazole derivatives for the modulation, notably the inhibition of the activity or function of fatty acid synthase (FAS). Suitably, the present invention relates to the use of benzimidazoles in the treatment of cancer.
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- Microwave assisted, solvent free one pot synthesis of nitriles from aryl aldehydes on melamin formaldehyde as solid support
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Various aryl aldehydes underwent prompt one pot conversion into the corresponding nitriles in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation in the presence of ammonium acetate as catalyst.
- Rezaei, Ramin,Mohammadi, Mohammad Kazem,Rastin, Nedaa
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scheme or table
p. 993 - 996
(2010/10/02)
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- HENRY CONDENSATION UNDER HIGH PRESSURE. 2. EFFECT OF AROMATIC ALDEHYDE TYPE AND PRESSURE ON THE YIELD OF ω-NITROSTYRENES AND SECONDARY PROCESSES
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Condensation of aromatic aldehydes (I)-(XX) with EtNO2 and n-PrNO2 in AcOH in the presence of AcONH4 or i-BuNH2 gives primarily ω-nitrostyrenes (Ia, b) - (XXa, b) and small quantities of nitriles (Ic) - (XXc), oximes (Id) - (XXd), and ketones (Ie, f) - (XXe, f).The yields of (Ia, b) - (XXa, b) at P = 1 atm are higher for acceptor substitutents on the aromatic ring whereas at P = 10 kbar, they are higher for donor substituents.High pressures suppress the formation of (Ic-f) - (XXc-f) and the Z-isomers of (Ia, b) - (XXa, b).The high pressure technique is especially useful in the preparation of donor-substituted (Ia, b) - (XXa, b) which are intermediates in the synthesis of the psychotropic β-phenylethylamines.
- Agafonov, N. E.,Sedishev, I. P.,Dudin, A. V.,Kutin, A. A.,Stashina, G. A.,Zhulin, V. M.
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p. 366 - 372
(2007/10/02)
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- Synthesis and structure-activity relationship of new cephalosporins with amino heterocycles at C-7. Dependence of the antibacterial spectrum and β-lactamase stability on the pK(a) of the C-7 heterocycle
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Cephalosporins with new aminobenzimidazole and aminoimidazoline heterocycles at C-7 have been synthesized starting with versatile C-7 isocyanide dihalide synthons. The aminobenzimidazoles have a broad spectrum of antibacterial activity, including Gram-positive and Gram-negative organisms, but possess limited β-lactamase stability. In contrast, the aminoimidazolines have a narrow spectrum of antibacterial activity, limited to Gram-negative strains only, but possess outstanding β-lactamase stability. Structure-activity relationships are discussed in terms of their dependence on the pK(a) of the C-7 amino heterocycle, basic C-7 residues giving cephalosporins with exceptional β-lactamase stability.
- Jung,Delvare,Boucherot,Hamon,Ackerley,Betts
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p. 1110 - 1116
(2007/10/02)
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- Analogues of 1,5-bis(4-amidinophenoxy)pentane (pentamidine) in the treatment of experimental Pneumocystis carinii pneumonia
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A series of 33 analogues of the anti-Pneumocystis carinii drug 1,5-bis(4-amidinophenoxy)pentane (pentamidine) was synthesized for screening against a rat model of P. carinii pneumonia (PCP). Twenty-five of the compounds showed efficacy against PCP when compared to a saline-treated control group. Two compounds, 1,4-bis(4-amidinophenoxy)butane (butamidine, 6) and 1,3-bis(4-amidino-2-methoxyphenoxy)propane (DAMP, 16), were statistically more effective than the parent drug in treating PCP in the rat model of infection. In addition to their activity against PCP, the compounds were also evaluated for antitrypsin activity, ability to inhibit thymidylate synthetase, affinity for DNA, and toxicity. No correlation was observed between the tested molecular interactions of the diamidines and their effectiveness against PCP.
- Tidwell,Jones,Geratz,Ohemeng,Cory,Hall
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p. 1252 - 1257
(2007/10/02)
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- A MILD AND EFFICIENT PROCEDURE FOR DEHYDRATION OF PRIMARY CARBOXAMIDES TO NITRILES BY SILYL SULPHONYL POLYPHOSPHATES
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A new dehydration procedure is described for the conversion of aryl, aralkyl and aliphatic carboxamides to nitriles in high yields under mild conditions using silyl sulphonyl polyphosphates.
- Rao, C. Someswara,Rambabu, M.,Srinivasan, P. S.
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p. 1431 - 1436
(2007/10/02)
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