- PIII/PV=O Catalyzed Cascade Synthesis of N-Functionalized Azaheterocycles
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An organocatalytic method for the modular synthesis of diverse N-aryl and N-alkyl azaheterocycles (indoles, oxindoles, benzimidazoles, and quinoxalinediones) is reported. The method employs a small-ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide) and a hydrosilane reductant to drive the conversion of ortho-functionalized nitroarenes into azaheterocycles through sequential intermolecular reductive C?N cross coupling with boronic acids, followed by intramolecular cyclization. This method enables the rapid construction of azaheterocycles from readily available building blocks, including a regiospecific approach to N-substituted benzimidazoles and quinoxalinediones.
- Li, Gen,Luzung, Michael R.,Nykaza, Trevor V.,Radosevich, Alexander T.,Yang, Junyu
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supporting information
p. 4505 - 4510
(2020/02/05)
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- Regioselective nitration of anilines with Fe(NO3)3·9H2O as a promoter and a nitro source
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An efficient Fe(NO3)3·9H2O promoted ortho-nitration reaction of aniline derivatives has been developed. This reaction may go through a nitrogen dioxide radical (NO2) intermediate, which is generated by the thermal decomposition of iron(iii) nitrate. The practicality of the present method using nontoxic and inexpensive iron reagents has been shown by the broad substrate scope and applications.
- Gao, Yang,Mao, Yuanyou,Zhang, Biwei,Zhan, Yingying,Huo, Yanping
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supporting information
p. 3881 - 3884
(2018/06/08)
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- Preparation method of 3-hydroxyphenyl trifluoromethyl ether
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The invention provides a preparation method of 3-hydroxyphenyl trifluoromethyl ether. The preparation method comprises the following steps: taking 4-trifluoromethoxyaniline as a raw material; and successively carrying out acetylation, nitrification, deacetylation, deaminizating, reduction and hydrolysis reaction on the 4-trifluoromethoxyaniline to obtain the 3-hydroxyphenyl trifluoromethyl ether. The preparation method is high in yield of products, simple to operate and low in production cost; and industrialization is facilitated.
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Paragraph 0081; 0084; 0085; 0095; 0099; 0100; 0111; 0112
(2017/09/05)
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- Perenosins: A new class of anion transporter with anti-cancer activity
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A new class of anion transporter named 'perenosins' consisting of a pyrrole linked through an imine to either an indole, benzimidazole or indazole is reported. The indole containing members of the perenosin family function as effective transmembrane Cl-/NO3- antiporters and HCl cotransporters in a manner similar to the prodigiosenes. The compounds reduce the viability of MDA-MB-231 and MCF-7.
- Van Rossom, Wim,Asby, Daniel J.,Tavassoli, Ali,Gale, Philip A.
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supporting information
p. 2645 - 2650
(2016/03/05)
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- SUBSTITUTED PYRIDINE AND PYRAZINE BMI-1 INHIBITORS
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Amine substituted pyridine and pyrazine compounds and forms thereof that inhibit the function and reduce the level of B -cell specific Moloney murine leukemia virus integration site 1 (Bmi-1) protein and methods for their use to inhibit Bmi-1 function and reduce the level of Bmi-1 to treat a cancer mediated by Bmi-1 are described herein.
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Page/Page column 208
(2015/06/08)
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- Synthesis and antiprotozoal activity of some 2-(trifluoromethyl)-1H- benzimidazole bioisosteres
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A series of 2-(trifluoromethyl)-1H-benzimidazole derivatives with various 5- and 6-position bioisosteric substituents (-Cl, -F, -CF3, -CN), namely 1-7, were prepared using a short synthetic route. Each analogue was tested in vitro against the protozoa Giardia intestinalis and Trichomonas vaginalis in comparison with albendazole and metronidazole. Several analogues had IC50 values 1 μM against both species, which make them significantly more potent than either standard. Compound 4 [2,5(6)- bis(trifluoromethyl)-1H-benzimidazole], was 14 times more active than albendazole against T.:vaginalis. This compound (4) also showed moderate antimalarial activity against W2 and D6 strains of Plasmodium falciparum (5.98 and 6.12 μM, respectively). Studying further structure activity relationships through the use of bioisosteric substitution in these benzimidazolic derivatives should provide new leads against protozoal and possibly malarial diseases.
- Navarrete-Vazquez, Gabriel,Rojano-Vilchis, Maria De Monserrat,Yepez-Mulia, Lilian,Melendez, Victor,Gerena, Lucia,Hernandez-Campos, Alicia,Castillo, Rafael,Hernandez-Luis, Francisco
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p. 135 - 141
(2007/10/03)
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- Reductive cyclization with baker's yeast of 4-alkyl-2-nitro-acetanilides to 6-alkylbenzimidazoles and 1-hydroxy-2-methyl-6-alkylbenzimidazoles
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Reduction of 4-substituted 2-nitroacetanilides by baker's yeast in acid media effected cyclization, resulting in the formation of n-substituted 2-methylbenzimidazoles and 6-substituted 1-hydroxy-2-methylbenzimidazole via the chemo- and regioselective reduction of the 2-nitro aromatic group to amine or hydroxylamine.
- Navarro-Ocana,Olguin,Luna,Jimenez-Estrada,Barzana
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p. 2754 - 2756
(2007/10/03)
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- Syntheses and properties of 1-methyl-3-phenylaminobenzimidazolium salts, models of DNA adducts of N7-arylaminodeoxyguanosinium salt
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When arylaminating carcinogens are administered to cells, they mainly generate the C8-arylamino-2'-deoxyguanosine adduct in DNA. A mechanism for this was proposed in which N7-arylaminated 2'-deoxyguanosine acts as an intermediate; however, it remained unclear whether this is actually the case. To elucidate the mechanisms involved in the generation of this adduct, a series of 5-substituted 1-methylbenzimidazole derivatives were used as models of the imidazole moiety of 2'-deoxyguanosine. Syntheses of a series of 5-substituted (CH3, H, F, CF3, or NO2) 1-methyl-3-phenylaminobenzimidazolium salts (7) and their related compounds were carried out, and the chemical characteristics of these products were examined. Heating compound 7 at 80 °C for 48 h in H2O/MeOH provided 5-substituted 1-methyl-2-oxo-2,3-dihydrobenzimidazoles but only when this compound contained a CF3 or NO2 substituent. Compound 7 decomposed in alkaline media, and its rate of decomposition increased when this compound had a stronger electron-withdrawing substituent. The product obtained under these conditions was 4-substituted N1-methyl-2-phenylazoaniline. On the other hand, when 1-methyl-3-(4-nitrophenylamino)benzimidazolium salt was treated under the same conditions as described above, it generated a demethylated product, 1-(4-nitrophenylamino)benzimidazole, when heated in H2O/MeOH and N1-formyl-N1-methyl-2-phenylazoaniline when treated in alkaline media. When the chemical characteristics of 3-phenylamino and 3-amino groups were compared using 3-substituted 1-methyl-5-(trifluoromethyl)benzimidazoles, the 3-phenylamino derivative was found to be more reactive.
- Kaiya,Fujiwara,Kohda
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p. 993 - 1001
(2007/10/03)
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- Hypoxia-Selective Agents Derived from Quinoxaline 1,4-Di-N-oxides
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Hypoxic cells, which are a common feature of solid tumors, but not normal tissues, are resistant to both anticancer drugs and radiation therapy.Thus the identification of drugs with selective toxicity toward hypoxic cells is an important objective in anticancer chemotherapy.The benzotriazine di-N-oxide (SR 4233, Tirapazamine) has been shown to be an efficient and selective cytotoxin for hypoxic cells.Since the bioreductive activation of Tirapazamine is thought to be due to the presence of the 1,4-di-N-oxide moiety, a series of 3-aminoquinoxaline-2-carbonitrile 1,4-di-N-oxides with a range of electron-donating and -withdrawing substituents in the 6- and /or 7- positions has been synthesized and evaluated for toxicity to hypoxic cells.Electrochemical studies of the quinoxaline di-N-oxides and Tirapazamine showed that as the electron-withdrawing nature of the 6(7)-substituent increases, the reduction potential becomes more positive and the compound is more readily reduced.Apart from the unsubstituted 6a and the 6,7-dimethyl derivative 6c, the quinoxaline di-N-oxide have reduction potentials significantly more positive than Tirapazamine (Epc -0.90 V).The most potent cytotoxins to cells in culture were the 6,7-dichloro and 6,7-difluoro derivatives 6i and 6l, which were 30-fold more potent than Tirapazamine.The 6(7)-fluoro and 6(7)-chloro compounds, 6e and 6h, showed the greatest hypoxia selectivity.Four of the compounds, 6e, 6f, 6h and 6i, killed the inner cells of multicellular tumor spheroids in vitro.In vivo Balb/c mice tolerated a dose of these four compounds twice the size of that of Tirapazamine.This study demonstrates that quinoxaline 1,4-di-N-oxides could provide useful hypoxia-selective therapeutic agents.
- Monge, Antonio,Palop, Juan A.,Cerain, Adela Lopez de,Senador, Virginia,Martinez-Crespo, Francisko J.,et al.
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p. 1786 - 1792
(2007/10/02)
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