- Efficient nitriding reagent and application thereof
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The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
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Paragraph 0172-0175
(2021/03/31)
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- Hypervalent Iodine Reagent-Promoted Hofmann-Type Rearrangement/Carboxylation of Primary Amides
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A novel transformation of primary amides to secondary amides promoted by hypervalent iodine reagents was developed. The hypervalent iodine reagent-mediated Hofmann-type rearrangement generated an isocyanate intermediate, which was subsequently trapped by an in situ generated carboxylic acid from the hypervalent iodine reagent to provide the corresponding secondary amides. This method provided a facile and efficient route for the synthesis of secondary amides from primary amides and also revealed novel reactivities of hypervalent iodine reagents.
- Wang, Xia,Yang, Peng,Hu, Bo,Zhang, Qian,Li, Dong
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p. 2820 - 2826
(2021/02/01)
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- Electrochemical formation of: N, N ′-diarylhydrazines by dehydrogenative N-N homocoupling reaction
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Hydrazines represent a class of compounds of high interest due to their applicability as versatile starting materials in many important transformations. Herein, we report a synthetic approach to hydrazine derivatives using commercially available anilines and an anodic dehydrogenative N-N coupling reaction as the key step.
- Breising, Valentina M.,Kayser, Jacob M.,Kehl, Anton,Schollmeyer, Dieter,Liermann, Johannes C.,Waldvogel, Siegfried R.
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supporting information
p. 4348 - 4351
(2020/04/27)
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- Nitromethane as a nitrogen donor in Schmidt-type formation of amides and nitriles
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The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.
- Jiao, Ning,Liu, Jianzhong,Qiu, Xu,Song, Song,Wei, Jialiang,Wen, Xiaojin,Zhang, Cheng,Zhang, Ziyao
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supporting information
p. 281 - 285
(2020/01/28)
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- An Electrochemical Beckmann Rearrangement: Traditional Reaction via Modern Radical Mechanism
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Abstract: Electrosynthesis as a potential means of introducing heteroatoms into the carbon framework is rarely studied. Herein, the electrochemical Beckmann rearrangement, i. e. the direct electrolysis of ketoximes to amides, is presented for the first time. Using a constant current as the driving force, the reaction can be easily carried out under neutral conditions at room temperature. Based on a series of mechanistic studies, a novel radical Beckmann rearrangement mechanism is proposed. This electrochemical Beckmann rearrangement does not follow the trans-migration rule of the classical Beckmann rearrangement.
- Tang, Li,Wang, Zhi-Lv,He, Yan-Hong,Guan, Zhi
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p. 4929 - 4936
(2020/08/21)
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- An organocatalytic C-C bond cleavage approach: A metal-free and peroxide-free facile method for the synthesis of amide derivatives
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A facile organocatalytic approach has been devised towards the synthesis of amide derivatives using 1,3-dicarbonyls as easily available acyl-sources under peroxide-free reaction conditions. This transformation was accomplished by the cleavage of the C-C bond in the presence of TEMPO as an organocatalyst and excludes the use of transition-metals and harsh reaction conditions. A broad range of substrates with diverse functional groups were well tolerated and delivered the products in high yields.
- Vodnala, Nagaraju,Gujjarappa, Raghuram,Polina, Saibabu,Satheesh, Vanaparthi,Kaldhi, Dhananjaya,Kabi, Arup K.,Malakar, Chandi C.
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supporting information
p. 20940 - 20944
(2020/12/31)
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- Iodine and Br?nsted acid catalyzed C–C bond cleavage of 1,3-diketones for the acylation of amines
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A metal-free N-acylation method of anilines with 1,3-diketones has been developed, by using iodine and p-toluene sulfonic acid as the co-catalysts. The reaction can proceed in 1,4-dioxane at elevated temperature to produce the corresponding amides with 48–89% yields. Further, the gram-scale experiment was carried out under the standard conditions and the possible mechanism was proposed.
- Zhou, Xiao-Yu,Chen, Xia,Yang, Dan
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supporting information
p. 177 - 184
(2019/11/26)
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- Visible-light-induced Beckmann rearrangement by organic photoredox catalysis
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A facile and general strategy for efficient direct conversion of oximes to amides using an inexpensive organic photocatalyst and visible light is described. This radical Beckmann rearrangement can be performed under mild conditions. Various alkyl aryl ketoximes and diaryl ketoximes can be effectively converted into the corresponding amides in excellent yields.
- Tang, Li,Wang, Zhi-Lv,Wan, Hai-Lan,He, Yan-Hong,Guan, Zhi
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supporting information
p. 6182 - 6186
(2020/09/01)
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- Copper-Catalyzed Site-Selective Oxidative C?C Bond Cleavage of Simple Ketones for the Synthesis of Anilides and Paracetamol
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A copper-catalyzed approach for the N-acylation of anilines with acetone and acetophenones via C?C bond cleavage is described. Under the developed conditions both CHCl3 and CH2Cl2 were identified as potential C1-source to promote the transformation. The reaction features a site selective C?C bond cleavage to install the amide moieties with high functional-group compatibility and wide substrate scope. The developed method avoids the use of sensitive and narcotic agents. The method also represents an excellent complement to the previous protocols with lower E-factor (13.91 mg/1 mg) than current industrially used method (E-factor 17.54 mg/1 mg). The developed approach has also been extended for the effective preparation of pyridine derivatives and paracetamol in gram scale. The course of the reaction was monitored by 1H NMR as a preliminary investigation of the reaction mechanism. (Figure presented.).
- Vodnala, Nagaraju,Gujjarappa, Raghuram,Hazra, Chinmoy K.,Kaldhi, Dhananjaya,Kabi, Arup. K.,Beifuss, Uwe,Malakar, Chandi C.
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supporting information
p. 135 - 145
(2018/12/05)
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- Palladium(II)-Catalyzed Oxidative Homo- and Cross-Coupling of Aryl ortho -sp2 C-H Bonds of Anilides at Room Temperature
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The preparation of secondary 2,2'-bisanilides has been successfully achieved through an oxidative coupling of aryl ortho-sp2 C-H bonds of anilides in the presence of catalytic Pd(OAc)2 and K2S2O8 as an oxidant in MsOH/CF3CO2H (TFA) at room temperature (25 °C). The aromatic rings of anilides substituted by various electron-donating or electron-withdrawing groups are tolerant in these coupling reactions.
- Mei, Chong,Lu, Wenjun
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p. 4812 - 4823
(2018/04/26)
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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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- Harnessing the pyrroloquinoxaline scaffold for FAAH and MAGL interaction: Definition of the structural determinants for enzyme inhibition
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This paper describes the development of piperazine and 4-aminopiperidine carboxamides/carbamates supported on a pharmacogenic pyrroloquinoxaline scaffold as inhibitors of the endocannabinoid catabolizing enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Structure-activity relationships and molecular modelling studies allowed the definition of the structural requirements for dual FAAH/MAGL inhibition and led to the identification of a small set of derivatives (compounds 5e, i, k, m) displaying a balanced inhibitory profile against both enzymes, with compound 5m being the frontrunner of the subset. Favorable calculated physico-chemical properties suggest further investigation for specific analogues.
- Brindisi, Margherita,Brogi, Simone,Maramai, Samuele,Grillo, Alessandro,Borrelli, Giuseppe,Butini, Stefania,Novellino, Ettore,Allarà, Marco,Ligresti, Alessia,Campiani, Giuseppe,Di Marzo, Vincenzo,Gemma, Sandra
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p. 64651 - 64664
(2016/07/23)
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- A mild and practical procedure for synthesis of substituted 2-aminobenzophenones
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Abstract A convenient three-step procedure has been developed for synthesis of substituted 2-aminobenzophenones from substituted anilines. The anilines are first protected as acetanilides, by reaction with acetic anhydride. These are then benzoylated with (trichloromethyl)benzene in the presence of aluminium-generated 2-acetamidobenzophenone. Finally, removal of the acetyl group from the amino group provides the substituted 2-aminobenzophenones in moderate to good yields.
- Ma, Er-Qian,Wang, Ping,Li, Pei-He,Mo, Li-Ping
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p. 6433 - 6441
(2015/08/18)
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- Para-Selective C-H Amidation of Simple Arenes with Nitriles
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A para-selective C-H amidation of simple arenes with nitriles has been developed. By increasing the amount of arenes, a further meta-selective C-H arylation of the produced amides occurred. Both steric and electronic effects are utilized to control the selectivity, resulting in only para-selective amidation products. The readily available nitriles as amidation reagents instead of amides makes the synthesis of N-arylamides more accessible.
- Xiang, Shi-Kai,Li, Jin-Mei,Huang, He,Feng, Chun,Ni, Hai-Liang,Chen, Xiao-Zhen,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Redshaw, Carl
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supporting information
p. 3435 - 3440
(2016/01/25)
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- Pd-Catalyzed C-H activation/oxidative cyclization of acetanilide with norbornene: Concise access to functionalized indolines
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An efficient Pd-catalyzed oxidative cyclization reaction for the synthesis of functionalized indolines by direct C-H activation of acetanilide has been developed. The norbornylpalladium species formed via direct ortho C-H activation of acetanilides is supposed to be a key intermediate in this transformation. This journal is the Partner Organisations 2014.
- Gao, Yang,Huang, Yubing,Wu, Wanqing,Huang, Kefan,Jiang, Huanfeng
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supporting information
p. 8370 - 8373
(2014/07/22)
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- Divergent reactivities of o-haloanilides with CuO nanoparticles in water: A green synthesis of benzoxazoles and o-hydroxyanilides
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In the present study, three divergent reaction paths emerged when o-haloanilides were subjected to CuO nanoparticles in water. o-Halo (I, Br) phenylbenzamides in the presence of CuO nanoparticles and Cs2CO 3 in water at 100 °C provided o-hydroxyphenyl benzamides as the major product. However, a complete change in selectivity was observed in the presence of an organic base/ligand (TMEDA), giving 2-arylbenzoxazole as the exclusive product. The above selectivities were not clearly distinct when the corresponding alkylamides were treated either in the presence or absence of the ligand. A number of o-halophenyl alkylamides provided either exclusively o-dehalogenated products or a mixture of o-dehalogenated and o-hydroxylated products, but none gave 2-alkylbenzoxazoles. In addition to the above selectivities, the use of an environmentally friendly solvent (water) and base, and the recyclability of the catalyst make this procedure a benign alternative to the existing methods for the synthesis of these molecules, viz. o-hydroxybenzamides and o-arylbenzoxazoles.
- Khatun, Nilufa,Guin, Srimanta,Rout, Saroj Kumar,Patel, Bhisma K.
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p. 10770 - 10778
(2014/03/21)
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- H2O2-mediated oxidative formation of amides from aromatic amines and 1,3-diketones as acylation agents via C-C bond cleavage at room temperature in water under metal-free conditions
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1,3-Diketones, as novel acylation agents, reacted with aromatic amines promoted by commercially available H2O2 (30% aq.) as the sole oxidant at room temperature under metal-free conditions in water, leading to a novel and rapid amide bond formation strategy. The reported method is high-yielding, simple and mild, and is the first example of the use of 1,3-diketones as acylation agents via C-C bond cleavage.
- Sun, Xi,Wang, Min,Li, Pinhua,Zhang, Xiuli,Wang, Lei
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supporting information
p. 3289 - 3294
(2013/12/04)
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- Synthesis of N-arylamides by copper-catalyzed amination of aryl halides with nitriles
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A copper-catalyzed amination of aryl halides with nitriles has been developed. The use of nitriles as nitrogen nucleophiles can make the synthesis of N-arylamides more simple than that using amides through in-situ hydrolysis. A variety of N-arylamides and benzoxazole derivatives can be synthesized according to this approach. Copyright
- Xiang, Shi-Kai,Zhang, Dong-Xue,Hu, Hao,Shi, Jiang-Ling,Liao, Li-Guo,Feng, Chun,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Yang, Hua,Yu, Wen-Hao
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supporting information
p. 1495 - 1499
(2013/06/27)
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- Palladium-catalyzed oxidative C-H bond acylation of acetanilides with benzylic alcohols
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An efficient and clean method to construct C-C bonds has been developed via the acylation reaction of acetanilides with benzylic alcohols using tert-butyl hydroperoxide (TBHP) as oxidant catalyzed by palladium acetate in the presence of triflic acid (TfOH). The acylation reactions exhibit excellent reactivities, and up to 95% yield of the corresponding aryl ketone could be obtained under the optimal conditions. Copyright
- Yuan, Yu,Chen, Duanteng,Wang, Xiaowei
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supporting information; experimental part
p. 3373 - 3379
(2012/02/03)
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- Efficient and economic halogenation of aryl amines via arenediazonium tosylate salts
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Arenediazonium tosylate salts have been successfully employed as a new and efficient reagent in halogenation reactions. A novel and economic protocol has been developed for the bromination and chlorination of various anilines using arenediazonium tosylate salts. A wide variety of reaction conditions were studied in acetonitrile at either room temperature or 60 °C in the presence or absence of catalyst with good to excellent yields. A surprising result showed the formation of acetanilides as a major product of aniline and methyl-substituted aniline halogenations in high yields.
- Lee, Young Min,Moon, Mi Eun,Vajpayee, Vaishali,Filimonov, Victor D.,Chi, Ki-Whan
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experimental part
p. 7418 - 7422
(2010/10/01)
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- Nitroethane in polyphosphoric acid: A new reagent for acetamidation and amination of aromatic compounds
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A new method of acetamidation of aromatic compounds based on their reaction with nitroethane in polyphosphoric acid has been developed. Upon the hydrolysis of acetamides during the reaction mixture workup, the corresponding amines can be obtained. Georg Thieme Verlag Stuttgart New York.
- Aksenov, Alexander V.,Aksenov, Nicolai A.,Nadein, Oleg N.,Aksenova, Inna V.
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experimental part
p. 2628 - 2630
(2010/12/18)
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- A simple and highly efficient one-pot procedure for the synthesis of amides via beckmann rearrangements using 1-tosylimidazole (TsIm)
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A facile and highly efficient method for one-pot Beckmann rearrangement of ketoximes into N-substituted amides using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, ketoximes are refluxed with TsIm and Cs2CO3 in the presence of SiO2 as a recyclable catalyst in DMF affording the corresponding amides in high yields. This methodology is highly efficient and regioselective for various structurally diverse ketoximes including symmetrical and unsymmetrical as well as cyclic oximes. The results of quantum mechanical studies used to rationalize the experimental outcomes are discussed. Copyright Taylor & Francis Group, LLC.
- Rad, Mohammad Navid Soltani,Khalafi-Nezhad, Ali,Behrouz, Somayeh,Amini, Zohreh,Behrouz, Marzieh
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experimental part
p. 1658 - 1671
(2010/09/09)
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- Concise total synthesis of
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An efficient nine-step total synthesis of the annulated indole natural products.
- Buszek, Keith R.,Brown, Neil,Luo, Diheng
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supporting information; experimental part
p. 201 - 204
(2009/06/20)
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- Recognition properties of flavin analogues with bile acid-based receptors: Role of steric effects in hydrogen bond based molecular recognition
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The recognition properties of 7,8-dimethyl flavin analogues by bile acid-based receptors that contain 2,6-diaminopyridine and the dioctylamide of 2,6-diaminopyridine in CHCl3 were determined. The results show that the bile acid-based receptors bind 7,8-dimethyl flavin analogues less effectively as compared to 7,8-unsubstituted flavins reported earlier, which is contrary to the known fact that the association constants increase with increasing electron-donating capacity of the substituents at the 7 and 8 positions of the flavin analogues. CSIRO 2008.
- Chattopadhyay, Prosenjit,Nagpal, Rekha,Pandey, Pramod S.
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p. 216 - 222
(2008/09/18)
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- Thiourea-enhanced flavin photooxidation of benzyl alcohol
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Upon irradiation, flavin oxidises 4-methoxybenzyl alcohol to the corresponding aldehyde using aerial O2 as the terminal oxidant. We have observed that this reaction is significantly accelerated by the presence of thiourea. A series of thiourea-functionalised flavins has been prepared from flavin isothiocyanates and their photocatalytic efficiencies have been monitored by NMR. The alcohol photooxidation proceeds rapidly and cleanly with high turnover numbers of up to 580, exceeding previously reported performances. A likely mechanistic rationale for the more than 30-fold acceleration of the photo-redox reaction by thiourea has been derived from spectroscopic, electrochemical, and kinetic studies. Thus, thiourea acts as an electron-transfer mediator for the initial photooxidation of 4-methoxybenzyl alcohol by the excited flavins. This mechanism has similarities to electron-relay mechanisms in flavoenzymes, for which cysteine sulfenic acid intermediates are proposed. The observation that thiourea mediates flavin photo-redox processes is valuable for the design of more sophisticated photocatalysts based on Nature's best redox chromophore.
- Svoboda, Jiri,Schmaderer, Harald,Koenig, Burkhard
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supporting information; experimental part
p. 1854 - 1865
(2009/04/06)
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- Oligo(N-aryl glycines): A new twist on structured peptoids
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We explore strategies to enhance conformational ordering of N-substituted glycine peptoid oligomers. Peptoids bearing bulky N-alkyl side chains have previously been studied as important examples of biomimetic "foldamer" compounds, as they exhibit a capacity to populate helical structures featuring repeating cis-amide bonds. Substantial cis/trans amide bond isomerization, however, gives rise to conformational heterogeneity. Here, we report the use of N-aryl side chains as a tool to enforce the presence of trans-amide bonds, thereby engendering structural stability. Aniline derivatives and bromoacetic acid are used in the facile solid-phase synthesis of a diverse family of sequence-specific N-aryl glycine oligomers. Quantum mechanics calculations yield a detailed energy profile of the folding landscape and substantiate the hypothesis that the presence of anilide groups establishes a strong energetic preference for trans-amide bonds. X-ray crystallographic analysis and solution NMR studies verify this preference. Molecular modeling indicates that the linear oligomers can adopt helical structures resembling a polyproline type II helix. High resolution structures of macrocyclic oligomers incorporating both N-alkyl and N-aryl glycine units confirm the ability to direct the presence of trans-amide bonds specifically at N-aryl positions. These results are an important step in developing strategies for the rational de novo design of new structural motifs in biomimetic oligopeptoid systems.
- Shah, Neel H.,Butterfoss, Glenn L.,Nguyen, Khanh,Yoo, Barney,Bonneau, Richard,Rabenstein, Dallas L.,Kirshenbaum, Kent
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experimental part
p. 16622 - 16632
(2009/04/14)
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- ACYLATED SPIROPIPERIDINE DERIVATIVES AS MELANOCORTIN-4 RECEPTOR MODULATORS
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Certain novel N-acylated spiropiperidine derivatives are ligands of the human melanocortin receptor(s) and, in particular, are selective ligands of the human melanocortin-4 receptor (MC-4R). They are therefore useful for the treatment, control, or prevention of diseases and disorders responsive to the modulation of MC-4R, such as obesity, diabetes, nicotine addiction, alcoholism, sexual dysfunction, including erectile dysfunction and female sexual dysfunction.
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Page/Page column 65
(2010/11/27)
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- SDS/Ac2O/H2O: Surfactant-mediated cleavage of imines with acetic anhydride to carbonyls and acetanilides in water
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Surfactant (SDS)-mediated cleavage of imines was achieved with acetic anhydride to the corresponding carbonyls (aldehydes and ketones) and acetanilides in water at 25-30°C with very good to excellent yields, thus contributing significantly to the green chemistry concept. Copyright Taylor & Francis Group, LLC.
- Sharma, Saikat Das,Gogoi, Pranjal,Boruah, Monalisa,Konwar, Dilip
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p. 2473 - 2481
(2008/02/10)
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- One-step reductive amidation of nitro arenes: Application in the synthesis of Acetaminophen
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A novel thioacetate mediated one-step reductive acetamidation of aryl nitro compounds was developed and applied to an efficient synthesis of acetaminophen. The reaction also proceeds well without a solvent in the presence of a catalytic amount of surfactant.
- Bhattacharya, Apurba,Purohit, Vikram C.,Suarez, Victor,Tichkule, Ritesh,Parmer, Gaurang,Rinaldi, Frank
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p. 1861 - 1864
(2007/10/03)
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- ONE-POT REDUCTIVE ACETAMIDATION OF ARYL NITRO COMPOUNDS
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The present invention provides a method for the reductive acetamidation of an aryl nitro compound by reacting a substituted acid with an aryl nitro compound and adding a catalytic amount of a base with the substituted acid and the aryl nitro compound to form an acetamidation aryl nitro compound. The acetamidation aryl nitro compound is then purified.
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Page/Page column 12; 13
(2008/06/13)
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- ARYLAMINE-BASED COMPOUND AND ELECTROPHOTOGRAPHIC PHOTORECEPTOR AND IMAGE FORMING APPARATUS USING THE SAME
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PROBLEM TO BE SOLVED: To provide an electron charge-transporting substance capable of improving electric characteristics and image characteristics of an electrophotographic photoreceptor and excellent in solubility. SOLUTION: The arylamine-based compound is represented by general formula [1] (wherein R1 and R2 are each independently a methyl group; R3 and R4 are each independently a hydrogen atom or a methyl group; R1 and/or R2 is bonded at ortho position or para position to a nitrogen atom).
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Page/Page column 17
(2008/06/13)
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- Studies in Beckmann rearrangement of substituted benzophenone and acetophenone oximes
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The Beckmann rearrangement of substituted benzophenone and acetophenone oximes was effected using 'silferc' as catalyst, prepared by impregnating anhydrous FeCl3 on silica gel by co-grinding technique.
- Khadilkar, Bhushan M.,Upadhyaya, Dharita J.
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p. 1867 - 1873
(2007/10/03)
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- Triarylamine compounds useful in electrophotographic photoreceptors
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A triarylamine compound useful as a charge transport material of an electrophotographic photoreceptor, which represented by formula (I) STR1 wherein Ar1 and Ar2 each represents a phenyl group or a condensed ring group.
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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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- Improved synthesis of thromboxane A2 receptor antagonists with a dibenzoxepin ring system
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Two derivatives of sodium (E)-11-[2-(1-benzimidazolyl)ethylidene]11-oxo-6,11-dihydrodibenz[b,e]o xepin-2-carboxylate, novel nonprostanoid thromboxane A2 (TXA2) receptor antagonists, were synthesized from methyl 11-oxo-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate. The carbonyl group at C11 was converted into a formylmethylene, then into a 1-azadiene moiety by reaction with a 2-aminoformanilide derivative. Stereo- and regioselective elaboration of the unsymmetrical imidazoles was achieved through a sequence of the transformation of E,Z-1-azadiene intermediates to E isomers under acidic conditions followed by cyclization to imidazoles.
- Sugaya,Kato,Sakaguchi,Tomioka
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p. 1257 - 1262
(2007/10/02)
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- Herbicidal 2 methyl-4-phosphinylcinnolinium hydroxide inner salts
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Certain 2-methyl-4-phosphinylcinnolinium hydroxide inner salts, useful for controlling unwanted plants.
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- Use of certain cinnoline-4-carboxylic acids and congeners thereof for controlling the growth of unwanted plants
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The growth of unwanted plants is controlled by certain cinnoline-4-carboxylic acids and congeners thereof.
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- Method for preparing 4-hydroxycinnolines in a pH controlled system
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In the preparation of a 4-hydroxycinnoline wherein the diazonium salt of a 2-aminoacetophenone in aqueous solution is allowed to undergo cyclocondensation, the improvement that comprises maintaining the pH of the solution between about 4.0 and 8.5 during the cyclocondensation.
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