- Direct synthesis of pyridine derivatives
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We describe a single-step conversion of various N-vinyl and N-aryl amides to the corresponding pyridine and quinoline derivatives, respectively. The process involves amide activation with trifluoromethanesulfonic anhydride in the presence of 2-chloropyridine followed by π-nucleophile addition to the activated intermediate and annulation. Compatibility of this chemistry with sensitive N-vinyl amides, epimerizable substrates, and a variety of functional groups is noteworthy. Copyright
- Movassaghi, Mohammad,Hill, Matthew D.,Ahmad, Omar K.
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- Synthesis of 5,6,7,8-tetrahydroquinolines by thermolysis of oxime O-allyl ethers in the presence of boron trifluoride etherate
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Thermolysis of cyclohexanone oxime O-crotyl and O-cinnamyl ether in the presence of BF3-etherate regio-selectively gave 4-methyl- and 4-phenyl- 5,6,7,8-tetrahydroquinoline, while the addition of organic bases such as triethylamine and pyridine
- Koyama,Ogura,Tagahara,Miyashita,Irie
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- Selective N-cycle hydrogenation of quinolines with sodium borohydride in aqueous media catalyzed by hectorite-supported ruthenium nanoparticles: Dedicated to Professor Heinrich Lang on the occasion of his 60th birthday
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A new catalyst containing metallic ruthenium nanoparticles intercalated in hectorite (nanoRu'@hectorite) was found to catalyze the reduction of quinoline and quinoline derivatives by NaBH4in aqueous solution to give selectively the corresponding 1,2,3,4-tetrahydroquinolines (N-cycle hydrogenation). In most cases the reaction can be done under mild conditions (25–60 °C) without pressure equipment, conversion and selectivity being superior to 99%. In the case of sterically hindered derivatives, the reaction can be done in a pressure vessel under self-generated pressure (up to 9 bar). Isoquinoline and quinoxalines also undergo selective N-cycle hydrogenation, but 2-phenyl-quinoline is hydrogenated to give 2-phenyl-5,6,7,8-tetrahydroquinoline (C-cycle hydrogenation). Isotope labeling experiments combined with semi-empirical calculations of the electrostatic potentials support a heterolytic hydrogenation mechanism involving a hydride from NaBH4and a proton from H2O. The catalyst nanoRu'@hectorite can be recycled and reused.
- Sun, Bing,Carnevale, Diego,Süss-Fink, Georg
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- Direct synthesis of ring-fused quinolines and pyridines catalyzed byNNHY-ligated manganese complexes (Y = NR2or SR)
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Four cationic manganese(i) complexes, [(fac-NNHN)Mn(CO)3]Br (Mn-1-Mn-3) and [(fac-NNHS)Mn(CO)3]Br (Mn-4) (whereNNHis a 5,6,7,8-tetrahydro-8-quinolinamine moiety), have been synthesized and evaluated as catalysts for the direct synthesis of quinolines and pyridines by the reaction of a γ-amino alcohol with a ketone or secondary alcohol;NNHS-ligatedMn-4proved the most effective of the four catalysts. The reactions proceeded well in the presence of catalyst loadings in the range 0.5-5.0 mol% and tolerated diverse functional groups such as alkyl, cycloalkyl, alkoxy, chloride and hetero-aryl. A mechanism involving acceptorless dehydrogenation coupling (ADC) has been proposed on the basis of DFT calculations and experimental evidence. Significantly, this manganese-based catalytic protocol provides a promising green and environmentally friendly route to a wide range of synthetically important substituted monocyclic, bicyclic as well as tricyclicN-heterocycles (including 50 quinoline and 26 pyridine examples) with isolated yields of up to 93%.
- Han, Mingyang,Lin, Qing,Liu, Qingbin,Liu, Song,Ma, Ning,Solan, Gregory A.,Sun, Wen-Hua,Wang, Zheng,Yan, Xiuli
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p. 8026 - 8036
(2021/12/27)
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- Pincerlike manganese complex and preparation method thereof, related ligand and preparation method thereof, catalyst composition and application
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The invention discloses a pincerlike manganese complex, a preparation method thereof, a ligand for preparation, a preparation method of the ligand, a catalyst composition taking the complex as an active component and application of the catalyst composition. According to the pincerlike manganese complex, a cycloalkyl ring is introduced into a ligand framework, and by regulating and controlling the cyclic tension, flexibility and steric hindrance of the cycloalkyl ring, the reactivity and stability of the manganese metal center can be effectively adjusted, and the catalytic activity and substrate applicability of a manganese metal system are remarkably improved. The catalyst composition taking the pincerlike manganese complex as an active component has the advantages of high catalyst activity, wide substrate application range, mild reaction conditions and the like in the process of preparing quinoline or pyridine derivatives by catalyzing dehydrogenation coupling reaction of o-amino aromatic alcohol or gamma-amino alcohol, ketone or secondary alcohol; and the synthesis advantages of low cost and stable performance are embodied, the operation is simple, and the yield is high.
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Paragraph 0159-0165
(2021/07/31)
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- Optimized Scalable Synthesis of Chiral Iridium Pyridyl-Phosphinite (Pyridophos) Catalysts
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Iridium catalysts with chiral P,N ligands have greatly enhanced the scope of asymmetric olefin hydrogenation because they do not require a coordinating group near the C=C bond like Rh and Ru catalysts. Pyridophos ligands, possessing a conformationally restricted annulated pyridine framework linked to a phosphinite group, proved to be particularly effective, inducing high enantioselectivities in the hydrogenation of a remarkably broad range of substrates. Here we report the development of an efficient scalable synthesis for the two most versatile Ir-pyridophos catalysts, derived from 2-phenyl-8-hydroxy-5,6,7,8-tetrahydroquinoline or the analogue with a five-membered carbocyclic ring, respectively, by modification and optimization of the original synthetic route. The optimized route renders both catalysts readily accessible in multi-gram quantities in analytically pure form in overall yields of 26–37 %, starting from acetophenone and cyclopentanone or cyclohexanone, respectively. A major advantage of the new synthesis is the efficient and practical kinetic resolution of the late-stage pyridyl alcohol intermediates with commercial immobilized Candida antarctica lipase B, giving access to both enantiomers of these catalysts as essentially enantiopure compounds. The catalysts are obtained as crystalline solids, which are air-stable and can be stored for years at ?20 °C without notable decomposition.
- Müller, Marc-André,Gani?, Adnan,H?rmann, Esther,Kaiser, Stefan,Maywald, Matthias,Roseblade, Stephen J.,Schrems, Marcus G.,Schumacher, Andreas,Woodmansee, David,Pfaltz, Andreas
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- Synthesis of Pyridines, Quinolines, and Pyrimidines via Acceptorless Dehydrogenative Coupling Catalyzed by a Simple Bidentate P^ N Ligand Supported Ru Complex
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A ruthenium hydrido chloride complex (1) supported by a simple, heteroleptic bidentate P^N ligand (L1) containing a diarylphosphine and a benzannulated phenanthridine donor arm is reported. In the presence of base, complex 1 catalyzes multicomponent reactions using alcohol precursors to produce structurally diverse molecules including pyridines, quinolines, and pyrimidines via acceptorless dehydrogenative coupling pathways. Notably, L1 does not bear readily (de)protonated Br?nsted acidic or basic groups common to transition metal catalysts capable of these sorts of transformations, suggesting metal-ligand cooperativity does not play a significant role in the catalytic reactivity of 1. A rare example of an η2-aldehyde adduct of ruthenium was isolated and structurally characterized, and its role in acceptorless dehydrogenative coupling reactions is discussed.
- Mondal, Rajarshi,Herbert, David E.
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supporting information
p. 1310 - 1317
(2020/04/15)
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- 4-HO-TEMPO-Catalyzed Redox Annulation of Cyclopropanols with Oxime Acetates toward Pyridine Derivatives
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A 4-HO-TEMPO-catalyzed redox strategy for the synthesis of pyridines through the annulation of cyclopropanols and oxime acetates has been developed. This protocol features good functional group tolerance and high chemoselectivity and also promises to be efficient for the late-stage functionalization of skeletons of drugs and natural products. Mechanism studies indicate that the reaction involves the in situ generated α,β-unsaturated ketones and imines as the key intermediates, which are derived from cyclopropanols and oxime acetates via a TEMPO/TEMPOH redox cycle, respectively. The pyridine products are formed as a result of annulation of enones with imines followed by TEMPO-catalyzed oxidative aromatization by excess oxime acetates. This method not only realizes the TEMPO-catalyzed redox reaction but also broadens the frontiers for TEMPO in catalysis.
- Zhan, Jun-Long,Wu, Meng-Wei,Wei, Dian,Wei, Bang-Yi,Jiang, Yu,Yu, Wei,Han, Bing
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p. 4179 - 4188
(2019/05/01)
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- A Ruthenium Catalyst with Unprecedented Effectiveness for the Coupling Cyclization of - Amino Alcohols and Secondary Alcohols
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The ruthenium complex (8-(2-diphenylphosphinoethyl)aminotrihydroquinolinyl)(carbonyl)(hydrido)ruthenium chloride exhibited extremely high efficiency toward the coupling cyclization of -amino alcohols with secondary alcohols. The corresponding products, pyridine or quinoline derivatives, are obtained in good to high isolated yields. On comparison with literature catalysts whose noble-metal loading with respect to -amino alcohols reached 0.5-1.0 mol % for Ru and a record lowest of 0.04 mol % for Ir, the current catalyst achieves the same efficiency with a loading of 0.025 mol % for Ru. The mechanism of acceptorless dehydrogenative condensation (ADC) was proposed on the basis of DFT calculations; in addition, the reactive intermediates were determined by GC-MS, NMR, and single-crystal X-ray diffraction. The catalytic process is potentially suitable for industrial applications.
- Pan, Bing,Liu, Bo,Yue, Erlin,Liu, Qingbin,Yang, Xinzheng,Wang, Zheng,Sun, Wen-Hua
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p. 1247 - 1253
(2016/02/18)
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- Organometallic compound and organic light-emitting device including the same
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Disclosed are an organometallic compound having excellent electrical properties and thermal stability, and an organic light-emitting device comprising the organometallic compound. The organometallic compound is represented by chemical formula 1.COPYR
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Paragraph 0339-0340; 0357-0362
(2016/10/20)
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- Catalytic asymmetric hydrogenation of quinoline carbocycles: Unusual chemoselectivity in the hydrogenation of quinolines
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The reduction of quinolines selectively took place on their carbocyclic rings to give 5,6,7,8-tetrahydroquinolines, when the hydrogenation was conducted in the presence of a Ru(η3-methallyl)2(cod)-PhTRAP catalyst. The chiral ruthenium catalyst converted 8-substituted quinolines into chiral 5,6,7,8-tetrahydroquinolines with up to 91:9 er. This journal is
- Kuwano, Ryoichi,Ikeda, Ryuhei,Hirasada, Kazuki
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supporting information
p. 7558 - 7561
(2015/05/04)
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- Photophysical properties and OLED performance of light-emitting platinum(ii) complexes
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The synthesis, photophysical properties and application as emitters in solution-processed multi-layer organic light-emitting diodes (OLEDs) of a series of blue-green to red light-emitting phosphorescent platinum(ii) complexes are reported. These complexes consist of phenylisoquinoline, substituted phenylpyridines or tetrahydroquinolines as C^N cyclometalating ligands and dipivaloylmethane as an ancillary ligand. Depending on both the structure of the C^N cyclometalating ligands and the dopant concentration in the matrix, these platinum(ii) complexes exhibit different aggregation tendencies. This property affects the photoluminescence spectra of the investigated compounds and colour-stability of the fabricated OLEDs. Using the blue-green to yellow-green emitting complexes, the best results were obtained with the 2-(4- trifluoromethylphenyl)-5,6,7,8-tetrahydroquinoline based platinum(ii) complex. A maximum luminous efficiency of 4.88 cd A-1 and a power efficiency of 4.65 lm W-1, respectively, were achieved. Employing the red emitting phenylisoquinoline based complex as an emitter, colour-stable and efficient (4.71 cd A-1, 5.12 lm W-1) devices were obtained.
- Kourkoulos, Dimitrios,Karakus, Cüneyt,Hertel, Dirk,Alle, Ronald,Schmeding, Sebastian,Hummel, Johanna,Risch, Nikolaus,Holder, Elisabeth,Meerholz, Klaus
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supporting information
p. 13612 - 13621
(2013/09/23)
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- Direct synthesis of pyridines and quinolines by coupling of γ-amino-alcohols with secondary alcohols liberating H2 catalyzed by ruthenium pincer complexes
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A novel, one-step synthesis of substituted pyridine- and quinoline-derivatives was achieved by acceptorless dehydrogenative coupling of γ-aminoalcohols with secondary alcohols. The reaction involves consecutive C-N and C-C bond formation, catalyzed by a bipyridyl-based ruthenium pincer complex with a base.
- Srimani, Dipankar,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 6632 - 6634
(2013/07/26)
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- Synthesis of substituted pyridines and quinolines
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A variety of N-vinyl and N-aryl amides were converted to the corresponding pyridine and quinoline derivatives, respectively. Amide activation and nucleophilic addition of copper(I) (trimethylsilyl)acetylide efficiently provided the desired alkynyl imines. Ruthenium-catalyzed protodesilylation and cycloisomerization of these imines gave the corresponding azaheterocycles. Georg Thieme Verlag Stuttgart.
- Hill, Matthew D.,Movassaghi, Mohammad
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p. 1115 - 1119
(2008/02/02)
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- Iridium catalysts with bicyclic pyridine-phosphinite ligands: Asymmetric hydrogenation of olefins and furan derivatives
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(Chemical Equation Presented) Superior bicyclics: Iridium catalysts as 1 derived from pyridine-phosphinite ligands considerably extend the scope of asymmetric hydrogenation. In addition to various unfunctionalized and functionalized olefins, furans, and benzofurans, for which no catalysts were known before, are also hydrogenated with high enantioselectivity (see scheme).
- Kaiser, Stefan,Smidt, Sebastian P.,Pfaltz, Andreas
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p. 5194 - 5197
(2007/10/03)
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- Synthesis of substituted pyridine derivatives via the ruthenium-catalyzed cycloisomerization of 3-azadienynes
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We describe a two-step conversion of various N-vinyl and N-aryl amides to the corresponding substituted pyridines and quinolines, respectively. The process involves the direct conversion of amides, including sensitive N-vinyl amides, to the corresponding trimethylsilyl alkynyl imines followed by a ruthenium-catalyzed protodesilylation and cycloisomerization. A wide range of new alkynyl imines are prepared and readily converted to the corresponding azaheterocycles. Copyright
- Movassaghi, Mohammad,Hill, Matthew D.
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p. 4592 - 4593
(2007/10/03)
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- Chemokine receptor binding heterocyclic compounds
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This invention relates to a novel class of heterocyclic compounds that bind chemokine receptors, inhibiting the binding of their natural ligands thereby. These compounds result in protective effects against infection by HIV through binding to chemokine receptors, including CXCR4 and CCR5, thus inhibiting the subsequent binding by these chemokines. The present invention provides a compound of Formula I wherein, W is a nitrogen atom and Y is absent or, W is a carbon atom and Y═H; R1to R7may be the same or different and are independently selected from hydrogen or straight, branched or cyclic C1-6alkyl; R8is a substituted heterocyclic group or a substituted aromatic group Ar is an aromatic or heteroaromatic ring each optionally substituted at single or multiple, non-linking positions with electron-donating or withdrawing groups; n and n′ are independently, 0-2; X is a group of the formula: Wherein, Ring A is an optionally substituted, saturated or unsaturated 5 or 6-membered ring, and P is an optionally substituted carbon atom, an optionally substituted nitrogen atom, sulfur or oxygen atom. Ring B is an optionally substituted 5 to 7-membered ring. Ring A and Ring B in the above formula can be connected to the group W from any position via the group V, wherein V is a chemical bond, a (CH2)n″group (where n″=0-2) or a C═O group. Z is, (1) a hydrogen atom, (2) an optionally substituted C1-6alkyl group, (3) a C0-6alkyl group substituted with an optionally substituted aromatic or heterocyclic group, (4) an optionally substituted C0-6alkylamino or C3-7cycloalkylamino group, (5) an optionally substituted carbonyl group or sulfonyl. These compounds further include any pharmaceutically acceptable acid addition salts and metal complexes thereof and any stereoisomeric forms and mixtures of stereoisomeric forms thereof.
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(2008/06/13)
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- Concise preparation of amino-5,6,7,8-tetrahydroquinolines and amino-5,6,7,8-tetrahydroisoquinolines via catalytic hydrogenation of acetamidoquinolines and acetamidoisoquinolines
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A method to prepare amino-substituted 5,6,7,8- tetrahydroquinolines and 5,6,7,8-tetrahydroisoquinolines via catalytic hydrogenation of the corresponding acetamido-substituted quinolines and isoquinolines followed by acetamide hydrolysis is described. The
- Skupinska, Krystyna A.,McEachern, Ernest J.,Skerlj, Renato T.,Bridger, Gary J.
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p. 7890 - 7893
(2007/10/03)
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- Efficient Preparation of Substituted 5,6,7,8-Tetrahydroquinolines and Octahydroacridine Derivatives
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The reaction of the enamine 4 with different β-amino ketone hydrochlorides 3a-e affords the diketones 5a-e which can be cyclized to the corresponding mono- and disubstituted tetrahydroquinolines 6a-e. Furthermore the preparation of the octahydroacridines 8f and 8g by using a straightforward multi step sequence is described.
- Sielemann, Dirk,Keuper, Ralf,Risch, Nikolaus
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p. 487 - 491
(2007/10/03)
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- Synthesis of Substituted 5,6,7,8-Tetrahydroquinolines from Conjugated Ketoximes
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A number of 5,6,7,8-tetrahydroquinolines have been prepared by heating conjugated ketoximes at 300 deg C in a sealed tube.
- Chelucci, G.,Cossu, S.,Soccolini, F.
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p. 1283 - 1286
(2007/10/02)
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- FORMATION OF NITROGEN HETEROCYCLES IN THE HYDROAMINATION OF 1,5-DIKETONES
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It was established that the principal pathway in the catalytic hydro(alkyl,aryl)amination of 1,5-diketones is, depending on the structure of the diketone and the amine component, the stereospecific formation of substituted piperidines, octa- and decahydroquinolines, and perhydroacridines or pyridine and tetrahydro- and benzodihydroquinoline structures.
- Kharchenko, V. G.,Kriven'ko, A. P.,Fedotova, O. V.,Nikolaeva, T. G.
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p. 720 - 723
(2007/10/02)
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- Certain 5,6,7,8-tetrahydroquinoline-8-thiocarboxamides
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The invention relates to novel pyridine derivatives which have a fused 5,6, or 7-membered saturated hydrocarbon ring adjacent to the nitrogen of the pyridine ring, and a group X situated on said hydrocarbon ring and separated by one carbon atom from the pyridine nitrogen atom, said group X is cyano, CONHR3, CSNHR3 or CO2 R5 wherein R3 is selected from hydrogen, lower alkyl and lower aralkyl radicals and R5 is selected from hydrogen, lower alkyl and lower aralkyl radicals which may be substituted by alkyl, alkoxy, halogen, nitro or trifluoromethyl; other substituents may be present. Compounds wherein X is CSNHR3 are anti-ulcer agents and the other compounds are intermediates therefor.
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- 8-Carboxylester, and 8-carbamyl derivitives of 5,6,7,8-tetrahydroquinoline
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The invention relates to novel 5,6,7,8-tetrahydroquinoline derivatives which have a group X situated at the 8-position said group X is CONHR3, or CO2 R5 wherein R3 is hydrogen lower alkyl and R5 is hydrogen, lower alkyl or a lower aralkyl radical. The compounds are intermediates for corresponding compounds where X is CSNHR3 and these are anti-ulcer agents.
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- 8-Cyano-5,6,7,8-tetrahydroquinoline derivatives
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The invention relates to novel 8-cyano-5,6,7,8-tetrahydroquinoline derivatives which are intermediates for the preparation of corresponding 8-thioamides. Some of the 8-cyano compounds are anti-ulcer agents.
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- Cyclopenteno[b]pyridine derivatives
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The invention relates to novel cyclopenteno[b]pyridine derivatives which have a group X on the 7-position and related tricyclic compounds. X is CONHR3, or CO2 R5 wherein R3 is hydrogen or lower alkyl and R5 is hydrogen or a lower alkyl or lower aralkyl group which may be substituted by alkyl, alkoxy, halogen, nitro or trifluoromethyl; other substituents may be present. The compounds are intermediates for compounds wherein X is CSNHR3 which are anti-ulcer agents.
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- Cyclopenteno[b]pyridine derivatives
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The invention relates to novel cyclopenteno[b]pyridine derivatives which have a thioamide group in the 7-position and related tricyclic compounds. The compounds are anti-ulcer agents.
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- Pharmaceutical compositions containing 5,6,7,8-tetrahydroquinoline derivatives and related compounds
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The invention relates to pharmaceutical compositions containing 5,6,7,8-tetrahydroquinoline-8-thioamides and nitriles and related tricyclic compounds and methods of treating ulcers using said compounds.
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