- An organic-base catalyzed asymmetric 1,4-addition of tritylthiol to: In situ generated aza- o -quinone methides at the H2O/DCM interface
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Based on an efficient method for in situ generation of N-o-QM species in the presence of a base, enantioselective catalytic conjugated additions of tritylthiol to in situ generated N-o-QMs are reported. Acid-base bifunctional organocatalyst 4c (10 mol%) enables these transformations with high stereoselectivities (up to 94% ee) using H2O/DCM as a solvent under mild conditions.
- Liu, Xianghui,Wang, Kai,Guo, Wengang,Liu, Yan,Li, Can
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Read Online
- Non-alkylator anti-glioblastoma agents induced cell cycle G2/M arrest and apoptosis: Design, in silico physicochemical and SAR studies of 2-aminoquinoline-3-carboxamides
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Malignant gliomas are the most common brain tumors, with generally dismal prognosis, early clinical deterioration and high mortality. Recently, 2-aminoquinoline scaffold derivatives have shown pronounced activity in central nervous system disorders. We herein reported a series of 2-aminoquinoline-3-carboxamides as novel non-alkylator anti-glioblastoma agents. The synthesized compounds showed comparable activity to cisplatin against glioblastoma cell line U87 MG in vitro. Among them, we found that 6a displayed good inhibitory activity against A172 and U118 MG glioblastoma cell lines and induced cell cycle arrest in the G2/M phase and apoptosis in U87 MG by flow cytometry analysis. Additionally, 6a displayed low cytotoxicity to several normal human cell lines. In silico study showed 6a had promising physicochemical properties and was predicted to cross the blood–brain barrier. Moreover, preliminary structure–activity relationships are also investigated, shedding light on further modifications towards more potent agents on this series of compounds. Our results suggest this compound has a promising potential as an anti-glioblastoma agent with a differential effect between tumor and non-malignant cells.
- Gu, Xiangyu,Liu, Jianwen,Ni, Xintong,Qi, Yingxue,Qian, Xuhong,Shao, Xusheng,Xu, Xiaoyong,Yuan, Pengtao
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- Ability of the Putative Decomposition Products of 2,3-dioxetanes of Indoles to Photosensitize Cyclobutane Pyrimidine Dimer (CPD) Formation and its Implications for the “Dark” (Chemisensitized) Pathway to CPDs in Melanocytes?
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The formation of cyclobutane pyrimidine dimers (CPDs) by a “dark” pathway in melanocytes has been attributed to chemisensitization by dioxetanes produced from peroxynitrite oxidation of melanin or melanin precursors. These dioxetanes are proposed to decompose to triplet state compounds which sensitize CPD formation by triplet–triplet energy transfer. To determine whether such compounds are capable of sensitizing CPD formation, the putative decomposition products of 2,3-dioxetanes of variously substituted indoles were synthesized and their triplet state energies determined at 77?K. Their ability to photosensitize CPD formation was determined by an enzyme-coupled gel electrophoresis assay in comparison with norfloxacin (NFX) which has the lowest triplet energy known to sensitize CPD formation. The decomposition products of 2,3-dioxetanes of 5-hydroxy and 5,6-dimethoxy indoles used as models for melanin precursors had lower triplet energies and were incapable of photosensitizing CPD formation. Theoretical calculations suggest that the decomposition products of the 2,3-dioxetanes of melanin precursors DHI and DHICA will have similarly low triplet energies. Decomposition products of the 2,3-dioxetanes of indoles lacking oxygen substituents had higher triplet energies than NFX and were capable of photosensitizing CPD formation, suggesting that peroxynitrite oxidation of tryptophan could play a hitherto unrecognized role in the dark pathway to CPDs.
- Cacchillo, Elena M.,Niedzwiedzki, Dariusz M.,Taylor, John-Stephen,Wang, Yanjing
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- PPTS-Catalyzed Bicyclization Reaction of 2-Isocyanobenzaldehydes with Various Amines: Synthesis of Diverse Fused Quinazolines
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A PPTS (pyridinium p-toluenesulfonate)-catalyzed bicyclization reaction of 2-isocyanobenzaldehydes as 1,5-dielectrophiles with various amines has been developed. The reaction not only provides a simple and efficient strategy for the assembly of structurally diverse fused quinazoline derivatives from readily available substrates under metal-free and mild conditions in a single step with only water and hydrogen as the by-products, but also opens the way to the application of o-formyl arylisocyanides in the synthesis of nitrogen-containing heterocycles. (Figure presented.).
- Meng, Xiang-He,Wu, Dan-Ni,Zhang, Yu-Jia,Zhao, Yu-Long
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supporting information
p. 1923 - 1929
(2021/02/26)
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- Repurposing an Aldolase for the Chemoenzymatic Synthesis of Substituted Quinolines
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Quinoline derivatives are important natural products and pharmaceuticals, but their synthesis can be challenging due to poor yields, harsh reaction conditions, and instability of starting materials. Here we report the chemoenzymatic synthesis of quinaldic acids under mild conditions using an aldolase, trans-o-hydroxybenzylidenepyruvate hydratase-aldolase (NahE, or HBPA). A series of 2-aminobenzaldehydes derived from reduction of the corresponding nitro analogue were reacted with pyruvate in the presence of NahE to give substituted quinolines in up to 93% isolated yield. This reaction differs from the aldol condensation catalyzed by NahE in vivo, instead resembling the heterocycle formation catalyzed by its homologue, dihydrodipicolinate synthase.
- Fansher, Douglas J.,Granger, Richard,Kaur, Satinderpal,Palmer, David R. J.
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p. 6939 - 6943
(2021/06/28)
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- Identification of Inhibitors of Cholesterol Transport Proteins Through the Synthesis of a Diverse, Sterol-Inspired Compound Collection
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Cholesterol transport proteins regulate a vast array of cellular processes including lipid metabolism, vesicular and non-vesicular trafficking, organelle contact sites, and autophagy. Despite their undoubted importance, the identification of selective modulators of this class of proteins has been challenging due to the structural similarities in the cholesterol-binding site. Herein we report a general strategy for the identification of selective inhibitors of cholesterol transport proteins via the synthesis of a diverse sterol-inspired compound collection. Fusion of a primary sterol fragment to an array of secondary privileged scaffolds led to the identification of potent and selective inhibitors of the cholesterol transport protein Aster-C, which displayed a surprising preference for the unnatural-sterol AB-ring stereochemistry and new inhibitors of Aster-A. We propose that this strategy can and should be applied to any therapeutically relevant sterol-binding protein.
- Laraia, Luca,Olsen, Asger Hegelund,Whitmarsh-Everiss, Thomas
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supporting information
p. 26755 - 26761
(2021/11/17)
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- Buchwald-Hartwig versus Microwave-Assisted Amination of Chloroquinolines: En Route to the Pyoverdin Chromophore
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The reaction of 2-chloro-6,7-dimethoxy-3-nitroquinoline with a series of amines and aminoalkanoates under basic microwave-mediated conditions and under Buchwald-Hartwig amination conditions is reported. The microwave irradiation favored the reaction with amines, resulting in yields of up to 80percent, whereas amino acid functionalization gave yields comparable to those of Buchwald-Hartwig amination. tert-Butyl (2 R)-4-[(6,7-dimethoxy-3-nitroquinolin-2-yl)amino]-2-hydroxybutanoate was successfully cyclized to the pyoverdin chromophore, a subunit of siderophores.
- Altevogt, Luca,Baro, Angelika,Bilitewski, Ursula,Freund, Marcel,Laschat, Sabine,Lin, Yulin,Rudolf, Richard,Seubert, Philipp
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p. 1177 - 1181
(2020/07/20)
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- Effective and Sustainable Access to Quinolines and Acridines: A Heterogeneous Imidazolium Salt Mediates C–C and C–N Bond Formation
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Quinoline and acridine derivatives have been prepared using a functionalized imidazolium salt as heterogeneous catalyst. Different ketones have been coupled with 2-aminobenzaldehydes and 2-aminoaryl ketones under solvent-free conditions, employing 1,3-bis(carboxymethyl)-imidazolium chloride as a catalyst. The protocol is simple and effective for the synthesis of a variety of nitrogen containing heterocycles (> 35 examples) with moderate to excellent yields (up to 96 %), being possible to perform the reaction in preparative scale. Additionally, 3-acetylquinolines have been transformed, under solvent-free conditions, into quinolyl chalcone derivatives by means of the same catalyst. Thus, the catalytic system mediates both reactions effectively in a tandem procedure. Furthermore, the catalyst is easily separated from the reaction mixture and can be reused without loss of activity (up to 8 cycles) which remarks its sturdiness. The E-factors are in the range of 14–23, both for the formation of quinolines and for the tandem reaction, which demonstrates the sustainability of the protocols described.
- Gisbert, Patricia,Albert-Soriano, María,Pastor, Isidro M.
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p. 4928 - 4940
(2019/08/12)
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- PYRIDINE COMPOUND
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PROBLEM TO BE SOLVED: To provide a compound having selective RET kinase inhibitory action and useful for the treatment of cancer, or a pharmaceutically acceptable salt thereof. SOLUTION: The present invention provides a pyridinoquinoline derivative, having a 1,2-oxazolyl group, or a pyrazolyl group, represented by the following 2 compound, or a pharmaceutically acceptable salt thereof. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPO&INPIT
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Paragraph 0149
(2018/05/24)
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- Design and synthesis of new RAF kinase-inhibiting antiproliferative quinoline derivatives. Part 2: Diarylurea derivatives
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This article describes the design, synthesis, and biological screening of a new series of diarylurea derivatives possessing quinoline nucleus. Nine target compounds were selected by the National Cancer Institute (NCI, Bethesda, Maryland, USA) for in?vitro antiproliferative screening against a panel of 58 cancer cell lines of nine cancer types. Following one-dose initial screening, compounds 1d-g and 2b were selected for 5-dose screening in order to calculate their IC50and total growth inhibition (TGI) values against the cell lines. Compounds 1e and 1g were the most promising analogues. Both compounds showed strong potency and broad-spectrum antiproliferative activity against the different tested cancer types. Their IC50and TGI values were less than those of the reference drug, sorafenib, against most of the tested cell lines of the nine different cancer types. Furthermore, the most potent compounds 1d-g were tested against C-RAF kinase as a potential molecular target of this series of compounds. All of them showed high potency, and the most potent derivative was compound 1e (IC50?=?0.10?μM). It was further tested against a panel of another twelve kinases, and it showed selectivity against C-RAF kinase. This could be, at least in part, the possible mechanism of antiproliferative action of this series of compounds at molecular level. The binding modes of compounds 1e and 1g were studied by docking studies, which highlighted the importance of the urea linker compared with the amide linker.
- El-Gamal, Mohammed I.,Khan, Mohammad Ashrafuddin,Tarazi, Hamadeh,Abdel-Maksoud, Mohammed S.,Gamal El-Din, Mahmoud M.,Yoo, Kyung Ho,Oh, Chang-Hyun
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p. 413 - 423
(2017/01/13)
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- Synthesis of quinolines and naphthyridines: Via catalytic retro-aldol reaction of β-hydroxyketones with ortho -aminobenzaldehydes or nicotinaldehydes
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A Cu(i)-catalyzed retro-aldol reaction of β-hydroxyketones with ortho-aminobenzaldehydes and nicotinaldehydes is reported that produces a range of quinolines and naphthyridines with high efficiency and selectivity. This reaction uses β-hydroxyketones as a regiospecific ketone-protected enolate source via copper-catalyzed retro-aldol Cα-Cβ bond cleavage. The in situ generated copper enolate undergoes kinetically favorable cyclization with ortho-amino aryl aldehydes to produce quinolines and naphthyridines in a chemo- and regioselective manner. The mild and weakly basic reaction conditions also suppress possible side reactions of benzaldehydes under strongly basic conditions, resulting in improved reaction yields.
- Zhang, Song-Lin,Deng, Zhu-Qin
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supporting information
p. 8966 - 8970
(2016/10/05)
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- Diastereoselective construction of highly functionalized tetrahydroquinolinoisoxazole scaffolds via intramolecular nitrone cycloaddition
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A novel strategy towards the construction of highly diversified tetrahydroquinolinoisoxazole frameworks with high diastereoselectivity via intramolecular 1,3-dipolar nitrone cycloaddition reaction is described for the first time. All the synthesized tetrahydroquinolinoisoxazoles are new and obtained in excellent yields under catalyst free condition.
- Bakthadoss, Manickam,Devaraj, Anthonisamy
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p. 3954 - 3960
(2015/06/08)
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- Facile and efficient oxidation of quinazolines into quinazolin-4(3 H)-ones by peracetic acid
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A new approach to synthesize quinazoline-4(3H)-ones was achieved by oxidation of quinazolines using peracetic acid, which possesses some advantages of economic reagents, simplified operation, high efficiency, and environmental friendliness. Application of this method allowed us to synthesize a series of quinazolin-4(3H)-ones with different substituents at 6 and 7 positions in good to excellent yields, including the key intermediates of tyrosine kinase inhibitors such as PD153035, Erlotinib, and Gefitinib. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the following free supplemental resource(s): Full experimental and spectral details.]
- Jin, Jian-Wen,Zhang, Lin,Meng, Guang-Rong,Zhu, Jian-Hua,Zhang, Qian
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p. 346 - 351
(2014/01/06)
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- Synthesis and preliminary cytotoxicity evaluation of new diarylamides and diarylureas possessing 2,3-dihydropyrrolo[3,2-b]quinoline scaffold
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A new series of diarylamides and diarylureas having 2,3-dihydropyrrolo[3,2- b]quinoline scaffold was synthesized. Their in vitro antiproliferative activities were tested over NCI-60 cancer cell lines of nine different cancer types. Some target compounds showed good inhibition percentages over different cell lines. Among all the target compounds, compound 1f possessing 6,7-dimethoxy-2,3-dihydropyrrolo[3,2-b]quinoline nucleus, amide linker, and 4-chloro-3-(trifluoromethyl)phenyl terminal ring showed high selectivity against MCF7 and MDAMB-468 breast cancer cell lines more than the other tested cell lines. Its inhibition percentages at 10 μM concentration over those two cell lines were 84.97% and 87.13%, respectively.
- Kim, Hyun-Jin,El-Gamal, Mohammed I.,Lee, Yong Sup,Oh, Chang-Hyun
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p. 2480 - 2486
(2013/09/24)
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- Gold(I)-catalyzed unprecedented rearrangement reaction between 2-aminobenzaldehydes with propargyl amines: An expedient route to 3-aminoquinolines
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Access to aminoquinolines: A gold(I)-catalyzed unprecedented rearrangement reaction between 2-aminobenzaldehydes with propargyl amine was studied. The study provided, for the first time, direct access to 3-aminoquinolines in one step starting from readily available starting materials (see scheme). Elegantly designed experiments were employed to unravel the mechanism of this unprecedented rearrangement, which are corroborated by DFT calculations.
- Patil, Nitin T.,Raut, Vivek S.,Shinde, Valmik S.,Gayatri, Gaddamanugu,Sastry, G. Narahari
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supporting information; experimental part
p. 5530 - 5535
(2012/05/21)
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- Cyanoacetamides (IV): Versatile one-pot route to 2-quinoline-3-carboxamides
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Cyanoacetic acid derivatives are the starting materials for a plethora of multicomponent reaction (MCR) scaffolds. Herein, we describe scope of a valuable general protocol for the synthesis of arrays of 2-aminoquinoline-3-carboxamides from cyanoacetamides and 2-aminobenzaldehydes or heterocyclic derivatives via a Friedlaender reaction variation. In many cases, the reactions involve a very convenient work up by simple precipitation and filtration. More than 40 new products are described. We foresee our protocol and the resulting derivatives becoming very valuable to greatly expanding the scaffold space of cyanoacetamide derivatives.
- Wang, Kan,Herdtweck, Eberhardt,Doemling, Alexander
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scheme or table
p. 316 - 322
(2012/06/18)
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- CARBOXYLIC ACID ARYL AMIDES
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Compounds of formula and pharmaceutically acceptable salts thereof are described, as well as the pharmaceutical compositions containing said compounds and their pharmaceutically acceptable salts, and the use of said compounds and pharmaceutical compositions for the treatment, control or amelioration of proliferative diseases, including cancer.
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Page/Page column 18
(2012/07/28)
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- Efficient syntheses of the unknown quinolino[2,3- c ]cinnolines; Synthesis of neocryptolepines
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A facile, efficient, three-step protocol for the synthesis of the unknown quinolino[2,3-c]cinnoline 5 is introduced. In addition, a new approach for the preparation of the biologically active neocryptolepines 8 in good overall yields is described.
- Haddadin, Makhluf J.,Bou Zerdan, Raghida M.,Kurth, Mark J.,Fettinger, James C.
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supporting information; experimental part
p. 5502 - 5505
(2011/03/18)
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- A simple and efficient approach to the synthesis of 2-phenylquinazolines via sp3 C-H functionalization
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(Figure presented) A facile and novel approach to the synthesis of 2-phenylquinazolines was developed via a tandem reaction following sp 3 C-H functionalization. Twenty-five examples of 2-phenylquinazolines were obtained from easily available 2-aminobenzophenones and benzylic amines with good to excellent yields.
- Zhang, Jintang,Zhu, Dapeng,Yu, Chenmin,Wan, Changfeng,Wang, Zhiyong
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supporting information; experimental part
p. 2841 - 2843
(2010/09/04)
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- A novel and efficient methodology for the construction of quinazolines based on supported copper oxide nanoparticles
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A series of quinazolines were synthesized from 2-aminobenzophenones and benzylic amines in good to excellent yields by employing a new heterogeneous catalyst based on the copper oxide nanoparticles supported on kaolin.
- Zhang, Jintang,Yu, Chenmin,Wang, Sujing,Wan, Changfeng,Wang, Zhiyong
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supporting information; experimental part
p. 5244 - 5246
(2010/09/05)
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- Efficient synthesis of novel six-member ring-fused quinoline derivatives via the Friedlaender reaction
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Novel quinolines fused with a six-member ring 5a-j were prepared in high yields (75-95%) via the Friedlaender reaction of dimethoxy-substituted o-aminobenzaldehydes of 3a or 3b with cyclic ketones 4, respectively. The structures of 5aj were determined by IR, 1H NMR, MS, and elemental analysis.
- Yang, Dingqiao,Guo, Wei,Cai, Yuepeng,Jiang, Lasheng,Jiang, Kailing,Wu, Xiaobing
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p. 229 - 233
(2008/09/19)
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- A facile synthesis of 2-methylquinolines via Pd-catalyzed aza-Wacker oxidative cyclization
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(Chemical Equation Presented) A novel Pd-catalyzed Wacker-type oxidative cyclization under air is described. By using this cyclization, a series of 2-methylquinolines are readily prepared with good yields under mild conditions.
- Zhang, Zuhui,Tan, Jiajing,Wang, Zhiyong
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p. 173 - 175
(2008/09/18)
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- Furan ring opening-indole ring closure: Synthesis of furo[2′, 3′:3,4]-cycloheota[1,2-b]indolium chlorides
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A new synthetic approach to furo[2′,3′:3,4]cyclohepta[1,2-b] indolium chlorides is elaborated starting from 2-acetylaminoaryldifurylmethanes or 2-aminoaryldifurylmethanes under treatment with methanolic HCl solution. The reaction proceeds in three steps: recyclization, intramolecular cyclization, and disproportionation. In this case the furan ring takes part in building up both pyrrole and seven-membered rings. The same salts can be obtained directly from 2-acetylaminobenzaldehydes and 2-methylfuran under similar conditions without isolation of corresponding 2-acetylaminoaryldifurylmethanes.
- Butin, Alexander V.,Smirnov, Sergey K.,Stroganova, Tatyana A.
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p. 623 - 628
(2007/10/03)
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- Facile synthesis of 3-substituted and 1,3-disubstituted quinolin-2(1H)-ones from 2-nitrobenzaldehydes
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2-Nitrobenzaldehydes were reduced with iron powder to 2-aminobenzaldehydes, which were reacted immediately with acyl chlorides to provide 2-carboxamidobenzaldehydes (1) with overall yields of 71-90 %. Reaction of 1 with base provided 3-substituted quinolin-2(1H)-ones with 63-97 % yields. Treatment of 1 with methyl iodide and base gave 1-methyl-3-substituted quinolin-2(1H)-ones with 82-95 % yields, whereas the treatment with isopropyl iodide gave 1-isopropyl-3-substituted quinolin-2(1H)-ones with 7-42 % yields.
- Park, Kwanghee Koh,Jung, Jin Young
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p. 2095 - 2105
(2007/10/03)
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- Concerning the mechanism of the Friedlaender quinoline synthesis
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Detailed experiments regarding the mechanism of the Friedlaender synthesis of quinolines from o-amino-benzaldehydes and simple aldehydes or ketones are described. Under the basic or acidic conditions commonly used in this reaction, it is concluded that the first step involves a slow intermolecular aldol condensation of the aldehyde or ketone with the o-aminobenzaldehyde. The aldol adduct 5 generated in this manner then undergoes very rapid cyclization to 4, which subsequently loses water to produce the quinoline derivative 8. Both 5 and 4 are too short lived to be detectable (TLC), even when deliberately generated by other means. It is also shown that E-enones corresponding to 6, i.e., the aldol dehydration product, are converted into quinolines (e.g., 21a and 21b from 17a and 17b) under basic or acidic conditions. Such enones are not detected as intermediates in the base-induced Friedlaender synthesis, even though certain congeners (17b) would be easily observable. Under acidic conditions these enones are too short lived to be detectable. Schiff bases derived from 2-aminobenzaldehyde (18a) and aldehydes or ketones can be generated under special conditions, but they show reactivity patterns different from those seen in the usual Friedlaender condensations. Thus, the ytterbium-triflate-catalyzed reaction of aldehydes with 18a at room temperature in toluene generates the E-Schiff bases (33, R1 = H), from which isomeric mixtures of tetrahydroquinoline derivatives 26 are formed exclusively. At higher temperatures, the E-Schiff bases 33 are isomerized to the Z-Schiff bases 34, from which the 3-substituted quinoline derivatives 24 are formed as the major products under appropriate conditions. Also, the ytterbium-triflate-catalyzed reaction of 18a with the pyrrolidine enamines of the methyl-n-alkylketones 38a,b produces mixtures in which the 2-monosubstituted kinetic products 37b,d predominate over the 2,3-disubstituted thermodynamic products 21c,e by a factor of 4:1 to 5:1. These results are opposite to those observed under the usual basic or acidic Friedlaender reactions with methyl-n-alkylketones, where the thermodynamic products are usually strongly favored. The unusual kinetic:thermodynamic product ratios observed with 38a,b are ascribed to the generation and rapid cyclization of mixtures of the Schiff bases 35 and 36, in which the kinetic isomer 35 is highly predominant.
- Muchowski, Joseph M.,Maddox, Michael L.
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p. 461 - 478
(2007/10/03)
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- Synthesis of condensed quinolines and quinazolines as DNA ligands
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Among new condensed quinolines and quinazolines the design of which were inspired by anti-cancer DNA-binding alkaloids such as camptothecin and batracyclin, DNA binding tests identify the 8-methoxy-7- piperazinylpropoxyindeno[1,2-b]quinolin-11-one tetracyclic system as a new motif for DNA recognition.
- Malecki, Natacha,Carato, Pascal,Rigo, Benoit,Goossens, Jean-Francois,Houssin, Raymond,Bailly, Christian,Henichart, Jean-Pierre
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p. 641 - 647
(2007/10/03)
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- A facile one-pot synthesis of 2-substituted-3-aminoquinolines: Preparation of benzo[b]naphthyridine-3-carbonitriles
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A facile one-pot synthesis of 3-aminoquinolines from ortho- aminobenzaldehydes was developed. Ethyl 6,7-dimethoxy-3-aminoquinoline-2- carboxylate, a key intermediate for the preparation of a 4-anilino-benzo[b][1,5] -naphthyridine-3-carbonitrile, was efficiently prepared by this method. Synthetic routes to 4-anilino-benzo[b][1,5]-naphthyridine-3-carbonitrile and 4-anilino-benzo[b][1,8]-naphthyridine-3-carbonitrile are described.
- Wang, Yanong D.,Boschelli, Diane H.,Johnson, Steven,Honores, Erick
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p. 2937 - 2942
(2007/10/03)
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- Stable annelated chiral NADH models with a rigidified amide part in the quinoline series: Synthesis, reactivity and grafting on a Merrifield resin
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The synthesis of new chiral nicotinamide adenine dinucleotide hydrogenated models derived from quinoline is described. Using a biomimetic approach, the out-of-plane positioning of the amide carbonyl was obtained by involving the chiral auxiliary in a lactam structure. It is shown that electron-donating groups on the benzene ring of the quinoline structure are necessary to obtain high chemical yields during the reduction of methyl benzoylformate. An interesting variation of the enantioselectivity as a function of magnesium ion concentration has been observed. Under the best conditions, methyl mandelate was obtained in up to 95% ee (R). To facilitate the recycling of these models, grafting of reagent 4 on a Merrifield resin has been developed. The resulting polymer-supported reagent 4 was tested in the asymmetric reduction of methyl benzoylformate.
- Vitry, Christiane,Vasse, Jean-Luc,Dupas, Georges,Levacher, Vincent,Quéguiner, Guy,Bourguignon, Jean
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p. 3087 - 3098
(2007/10/03)
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- Electron Deficient Heteroaromatic Ammonioamidates. Part 26. N-(Quinazolin-3-io)amidates. Part 13. Phototransformations of an N-(Quinazolin-3-io)thioamidate and of a 10bH-1,3,4-thiadiazoloquinazoline, the Ring Isomer of an N-(Quinazolin-3-io)thioamidate, and the Photochemical Fo
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Irradiation of the N-(quinazolin-3-io)thioamidate (10a) in ethanol and butylamine solution furnished, in addition to several other compounds, the 4,4'-biquinazolinyl (12a), the quinazolinyl alcohol (13a) and the quinazolinyl ketone (13b), respectively, the mesoionic triazoloquinazolinylium thiolate (18a) and the corresponding olate (18b) as novel type photolysis products.In contrast, irradiation of the 10bH-1,3,4-thiadiazoloquinazoline (11b), the ring isomer of the N-(quinazolin-3-io)thioamidate (10b) furnishes, with cleavage of either the quinazoline or the thiadiazole ring , a mixture of the thiadiazoles (21a,b), and the quinazoline derivatives (14a), (22a,b) in addition to 3,4-dimethoxybenzonitrile.Irradiation of various sulphur-containing quinazoline derivatives, including the quinazolinethiones (14a,e), the methylthioquinazoline (13f) and the diquinazolinyl disulphide (24a), leads to the formation of 4,4'-biquinazolinyls (12a) and (12b), respectively.Irradiation of the quinazoline (13c), which carries no sulphur-containing substituent, does not lead to the formation of the biquinazolinyl (12a); irradiation of a mixture of quinazoline (13e) and quinazolinethione (14a) gives rise to the formation of a mixture of biquinazolinyls (12a-c) with incorporation of the ring of the sulphur-free starting quinazoline (13e) into the products (12a) and (12b).
- Lempert-Sreter, Magda,Lempert, Karoly,Moeller, Joergen
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p. 1143 - 1152
(2007/10/02)
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