- CNS and antimalarial activity of synthetic meridianin and psammopemmin analogs
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The marine invertebrate-derived meridianin A, the originally proposed structure for psammopemmin A, and several related 3-pyrimidylindole analogs were synthesized and subsequently investigated for central nervous system, antimalarial, and cytotoxic activity. A Suzuki coupling of an indoleborate ester to the pyrimidine electrophile was utilized to form the natural product and derivatives thereof. The 3-pyrimidineindoles were found to prevent radioligand binding to several CNS receptors and transporters, most notably, serotonin receptors (i for 5HT2B). Two compounds also inhibited the human malaria parasite Plasmodium falciparum (IC50 50 = 15 μM).
- Lebar, Matthew D.,Hahn, Kristopher N.,Mutka, Tina,Maignan, Patrick,McClintock, James B.,Amsler, Charles D.,Van Olphen, Alberto,Kyle, Dennis E.,Baker, Bill J.
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Read Online
- A NaH-promoted N-detosylation reaction of diverse p-toluenesulfonamides
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A NaH-mediated detosylation reaction of various Ts-protected indoles, azaheterocycles, anilines and dibenzylamine was reported. The method features cheap reagent, convenient operations, mild reaction conditions and broad substrate scope. Moreover, this study revealed that the loading of NaH in tosylation reactions of nitrogen-containing compounds with NaH as a base in DMA or DMF should be controlled due to the possibility of adverse detosylation.
- Sun, Wanwan,Chen, Xiaobei,Hu, Ying,Geng, Huihui,Jiang, Yuanrui,Zhou, Yuxin,Zhu, Wenjing,Hu, Min,Hu, Haohua,Wang, Xingyi,Wang, Xinli,Zhang, Shilei,Hu, Yanwei
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supporting information
(2020/10/05)
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- Potassium tert-Butoxide-Promoted Acceptorless Dehydrogenation of N-Heterocycles
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Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six- and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H2 gas in o-xylene at 140 °C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H2 gas. (Figure presented.).
- Liu, Tingting,Wu, Kaikai,Wang, Liandi,Yu, Zhengkun
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supporting information
p. 3958 - 3964
(2019/08/01)
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- Acceptorless Dehydrogenation of N-Heterocycles and Secondary Alcohols by Ru(II)-NNC Complexes Bearing a Pyrazoyl-indolyl-pyridine Ligand
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Ruthenium(II) hydride complexes bearing a pyrazolyl-(2-indol-1-yl)-pyridine ligand were synthesized and structurally characterized by NMR analysis and X-ray single crystal crystallographic determinations. These complexes efficiently catalyzed acceptorless dehydrogenation of N-heterocycles and secondary alcohols, respectively, exhibiting highly catalytic activity with a broad substrate scope. The present work has established a strategy to construct highly active transition metal complex catalysts and provides an atom-economical and environmentally benign protocol for the synthesis of aromatic N-heterocyclic compounds and ketones.
- Wang, Qingfu,Chai, Huining,Yu, Zhengkun
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p. 584 - 591
(2018/03/08)
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- A indole compound and its preparation method and application (by machine translation)
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The invention discloses a indole compound and its preparation method and application. The indole compounds of the structural formula such as formula (I) is shown. The indoles, rice galenical demonstrate the excellent inhibitory activity, the effect of most of the compound is obviously better than the positive control drug validamycin; especially compound I - 43, I - 44, I - 54, I - 73, II - 7 and II - 17, its galenical very good living body protection and treating effect, effect is better than the positive control; more specifically, compound I - 43 of the rice sheath blight bacteriostatic activity than validamycin activity is improved by nearly 300 times. The indole compounds in the prevention and/or treatment of rice sheath blight has great application prospects. In addition the compound of the invention is simple in construction, the preparation method is simple, and is suitable for large-scale industrial production. (I). (by machine translation)
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Paragraph 0131; 0132; 0133
(2018/10/02)
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- High efficiency two-photon uncaging coupled by the correction of spontaneous hydrolysis
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Two-photon (TP) uncaging of neurotransmitter molecules is the method of choice to mimic and study the subtleties of neuronal communication either in the intact brain or in slice preparations. However, the currently available caged materials are just at the limit of their usability and have several drawbacks. The local and focal nature of their use may for example be jeopardized by a high spontaneous hydrolysis rate of the commercially available compounds with increased photochemical release rate. Here, using quantum chemical modelling we show the mechanisms of hydrolysis and two-photon activation, and synthesized more effective caged compounds. Furthermore, we have developed a new enzymatic elimination method removing neurotransmitters inadvertently escaping from their compound during experiment. This method, usable both in one and two-photon experiments, allows for the use of materials with an increased rate of photochemical release. The efficiency of the new compound and the enzymatic method and of the new compound are demonstrated in neurophysiological experiments.
- Pálfi, Dénes,Chiovini, Balázs,Szalay, Gergely,Kaszás, Attila,Turi, Gergely F.,Katona, Gergely,ábrányi-Balogh, Péter,Szori, Milán,Potor, Attila,Frigyesi, Orsolya,Lukácsné Haveland, Csilla,Szadai, Zoltán,Madarász, Miklós,Vasanits-Zsigrai, Anikó,Molnár-Perl, Ibolya,Viskolcz, Béla,Csizmadia, Imre G.,Mucsi, Zoltán,Rózsa, Balázs
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p. 1958 - 1970
(2018/03/23)
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- Painting argyrins blue: Negishi cross-coupling for synthesis of deep-blue tryptophan analogue β-(1-azulenyl)-L alanine and its incorporation into argyrin C
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The argyrins are a family of non-ribosomal peptides that exhibits different biological activities through only small structural changes. Ideally, a biologically active molecule can be tracked and observed in a variety of biological and clinical settings in a non-invasive manner. As a step towards this goal, we report here a chemical synthesis of unnatural deep blue amino acid β-(1-azulenyl)-L alanine with different fluorescence and photophysical properties, which allows a spectral separation from the native tryptophan signal. This might be especially useful for cell localization studies and visualizing the targeted proteins. In particular, the synthesis of β-(1-azulenyl)-L alanine was achieved through a Negishi coupling which proved to be a powerful tool for the synthesis of unnatural tryptophan analogs. Upon β-(1-azulenyl)-L alanine incorporation into argyrin C, deep blue octapeptide variant was spectrally and structurally characterized.
- Stempel, Erik,Kaml, Robert Franz-Xaver,Budisa, Nediljko,Kalesse, Markus
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p. 5259 - 5269
(2018/05/16)
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- Preparation method of 4-hydroxyindole
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The invention discloses a preparation method of 4-hydroxyindole, comprising the steps of (1) dissolving 3-methoxyphenylhydrazine hydrochloride in DMF (dimethylformamide), adding concentrated sulfuricacid and a catalyst, mixing well, adding acetaldehyde, allowing reflux reaction at controlled temperature of 60-80 DEG C for 90-120 min, filtering after reaction is over to obtain 4-methoxyindole; (2)dissolving 4-methoxyindole in dichloromethane, adding the obtained solution in a reactor, introducing nitrogen, controlling the temperature to 50-70 DEG C, and introducing HBr into the solution, allowing reflux reaction for 45-90 min, lowering the temperature to room temperature, performing reduced pressure removal of a solvent, and recrystallizing to obtain 4-hydroxyindole. The preparation method according to the application is simple to perform and has mild conditions and few byproducts, the product is high in purity, and the yield of the product is high.
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Paragraph 0018-0020; 0025-0027; 0032-0034; 0039-0048
(2018/05/16)
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- Biotransformation of rutabaga phytoalexins by the fungus Alternaria brassicicola: Unveiling the first hybrid metabolite derived from a phytoalexin and a fungal polyketide
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The biotransformations of the rutabaga phytoalexins rutalexin, brassicanate A, isalexin and rapalexin A by the plant pathogenic fungus Alternaria brassicicola are reported. While the biotransformations of rutalexin, brassicanate A, and isalexin are fast, rapalexin A is resistant to fungal transformation. Unexpectedly, biotransformation of rutalexin yields a hybrid metabolite named rutapyrone, derived from rutalexin metabolism and phomapyrone G, a fungal metabolite produced by A. brassicicola. These fungal transformations are detoxification reactions likely carried out by different enzymes. The discovery of rapalexin A resistance to detoxification suggests that this phytoalexin in combination with additional phytoalexins could protect crucifers against this pathogen. Phytoalexins resistant to degradation by A. brassicicola are expected to provide the producing plants with higher disease resistance levels.
- Pedras, M. Soledade C.,Abdoli, Abbas
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- An Fmoc-compatible method for synthesis of peptides containing photocaged aspartic acid or glutamic acid
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A new method compatible with 9-fluorenylmethoxycarbonyl (Fmoc) solid phase peptide synthesis (SPPS) was developed to synthesize photocaged peptides carrying the photosensitive 4-methoxy-7-nitroindoline (MNI) group on the side chain of aspartic acid (Asp) and glutamic acid (Glu). The caged building blocks, Fmoc-Asp(MNI)-OH and Fmoc-Glu(MNI)-OH, could be readily synthesized on multi-gram scale. An important advantage of the new method is that the MNI group prevents the formation of aminosuccinyl side products and pyrrolidones during Fmoc SPPS and has rapid photolysis kinetics. Thus our method provides a useful approach for photocaging of peptides and proteins at side chain carboxylic groups.
- Tang, Shan,Cheng, Jing-Yuan,Zheng, Ji-Shen
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p. 4582 - 4585
(2015/07/02)
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- A highly active and recyclable catalyst for the synthesis of indole and phenyl ether
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A new simple catalytic system consisting of copper-aluminium and hydrotalcite (CuAl-HT) has been developed using a facile one-pot method without harm to the environment. The catalyst was characterized using TEM, XRD and XPS. It could be used as an efficient catalyst for the synthesis of both indole and phenyl ether. As expected, the catalyst afforded high catalytic activity for the selective synthesis of indole via intramolecular dehydrogenative N-heterocyclization of 2-(2-aminophenyl)ethanol. Meanwhile, it also exhibited superior catalytic properties for an Ullmann-type coupling reaction to synthesise phenyl ether from iodobenzene and phenol. The CuAl-HT catalyst showed higher activity than conventional catalysts based on copper and could be recycled several times with stable catalytic activity. This procedure has real economic advantages since no expensive materials were used.
- Qiao, Bo,Zhang, Le,Li, Rong
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p. 93463 - 93469
(2015/11/17)
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- 1,3,5-TRIAZINE-2-AMINE DERIVATIVES, PREPARATION THEREOF AND DIAGNOSTIC AND THERAPEUTIC USE THEREOF
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The present invention relates to compounds corresponding to formula (I) in which: - R1 represents a substituted phenyl; - R2 represents: - a substituted phenyl; - a heteroaromatic group, the said group being unsubstituted or substituted one or more times; - R3 represents a group Alk; - R4 represents a hydrogen atom or a (C1-C4)alkyl; - R5 represents a hydrogen atom, a (C3-C6)cycloalkyl or a (C1-C4)alkyl-O-Alk; - or alternatively R4 and R5, together with the nitrogen atom to which they are attached, constitute a heterocyclic radical chosen from: azetidin-1-yl, pyrrolidin-1-yl, piperid-1-yl, morpholin-4-yl; - R6 represents a group -COOAlk, a group -CONH2 or a group -NHSO2 Alk; - Alk represents a (C1-C4)alkyl, which is unsubstituted or substituted one or more times with a halogen atom; in the form of the base or of an acid-addition salt. Preparation process and diagnostic and therapeutic use
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Page/Page column 18-19
(2013/07/05)
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- Dissecting metabolic puzzles through isotope feeding: A novel amino acid in the biosynthetic pathway of the cruciferous phytoalexins rapalexin A and isocyalexin A
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Understanding defence pathways of plants is crucial to develop disease-resistant agronomic crops, an important element of sustainable agriculture. For this reason, natural plant defenses such as phytoalexins, involved in protecting plants against microbial pathogens, have enormous biotechnological appeal. Crucifers are economically important plants, with worldwide impact as oilseeds, vegetables of great dietetic value and even nutraceuticals. Notably, the intermediates involved in the biosynthetic pathways of unique cruciferous phytoalexins such as rapalexin A and isocyalexin A remain unknown. Toward this end, using numerous perdeuterated compounds, we have established the potential precursors of these unique phytoalexins and propose for the first time their detailed biosynthetic pathway. This pathway involves a variety of intermediates and a novel amino acid as the central piece of this complex puzzle. This work has set the stage for the discovery of enzymes and genes of the biosynthetic pathway of cruciferous phytoalexins of unique scaffolds.
- Pedras, M. Soledade C.,Yaya, Estifanos E.
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p. 1149 - 1166
(2013/03/29)
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- Total syntheses of mitragynine, paynantheine and speciogynine via an enantioselective thiourea-catalysed Pictet-Spengler reaction
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The pharmacologically interesting indole alkaloids (-)-mitragynine, (+)-paynantheine and (+)-speciogynine were synthesised in nine steps from 4-methoxytryptamine by a route featuring (i) an enantioselective thiourea-catalysed Pictet-Spengler reaction, providing the tetrahydro-β- carboline ring and (ii) a Pd-catalysed Tsuji-Trost allylic alkylation, closing the D-ring. The Royal Society of Chemistry 2012..
- Kerschgens, Isabel P.,Claveau, Elise,Wanner, Martin J.,Ingemann, Steen,Van Maarseveen, Jan H.,Hiemstra, Henk
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supporting information
p. 12243 - 12245
(2013/01/16)
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- "on water" direct and site-selective Pd-catalysed C-H arylation of (NH)-indoles
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This communication describes the development of a versatile catalytic system based on palladium(II) acetate/bis(diphenylphosphino)methane [Pd(OAc)2/dppm] that works "on water" giving site-selective C-H arylation of (NH)-indoles without protecting or directing groups. Remarkably, the control of regioselectivity was achieved by small changes in the "extra-catalytic" base/halide partners. These innovative methodologies allow a high-yielding access to both C2 and C3-arylindoles, as well as 2,3-diarylindoles, and display high chemo/regioselectivities and structural versatility with regard to either indole or aryl moieties. Copyright
- Joucla, Lionel,Batail, Nelly,Djakovitch, Laurent
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supporting information; experimental part
p. 2929 - 2936
(2011/02/22)
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- INDOLE DERIVATIVES AND DRUGS CONTAINING THE SAME
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An indole derivative represented by the following general formula (1) : wherein at least one of R1, R2, R3, and R4 represents an alkoxy group containing 1 to 20 carbon atoms, and other groups of the R1, R2, R3, and R4 represent hydrogen, an alkyl group containing 1 to 6 carbon atoms, acetyl group, or hydroxyl group; and either one of X and Y represents -(CH2)nOH wherein n is an integer of 0 to 30, and the other one of the X and Y represents hydrogen atom; or a salt thereof; and a drug and an agent for promoting differentiation of a stem cell containing such indole derivative or its salt as an effective component. The indole derivative (1) of the present invention has action of inducing differentiation of neural stem cell specifically into a neuron, and this indole derivative is useful as a prophylactic or therapeutic drug for brain dysfunction or neuropathy caused by loss or degeneration of the neuron.
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Page/Page column 9
(2010/02/11)
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- Microwave assisted Leimgruber-Batcho reaction for the preparation of indoles, azaindoles and pyrroylquinolines
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The development of enhanced conditions for Lewis acid catalysed Leimgruber-Batcho indole synthesis using microwave acceleration is described. This approach has permitted the preparation of a variety of heteroaromatic enamine intermediates in good yield and high purities. Subsequent catalytic hydrogenation reactions, under various conditions including the use of a solid-phase encapsulated catalyst, furnish the corresponding indole derivatives in good yields.
- Siu, Jason,Baxendale, Ian R.,Ley, Steven V.
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p. 160 - 167
(2007/10/03)
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- Effects of indole fatty alcohols on the differentiation of neural stem cell derived neurospheres
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In a search for inducers of neuronal differentiation to treat neurodegenerative diseases such as Alzheimer's disease, a series of indole fatty alcohols (IFAs) were prepared, 13c (n = 18) was able to promote the differentiation of neural stem cell derived neurospheres into neurons at a concentration of 10 nM. Analysis of the expression of the Notch pathway genes in neurospheres treated during the differentiation phase with 13c (n = 18) revealed a significant decrease in the transcription of the Notch 4 receptor.
- Coowar, Djalil,Bouissac, Julien,Hanbali, Mazen,Paschaki, Marie,Mohier, Eliane,Luu, Bang
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p. 6270 - 6282
(2007/10/03)
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- Compounds and methods to treat cardiac failure and other disorders
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Indoles, benzimidazoles and benztriazoles which are substituted at the 5 or 6 position with a substituent comprising an aromatic moiety linked through a piperazine ring to said indole, benzimidazole or benztriazole are useful in treating cardiac conditions associated with heart failure and in treating conditions characterized by proinflammation.
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- CERTAIN FUSED PYRROLECARBOXAMIDES A NEW CLASS OF GABA BRAIN RECEPTOR LIGANDS
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Disclosed are compounds of formula I: STR1 wherein R 8 and R. sub.9 independently represent hydrogen or organic substituents; W represents optionally substituted thiazolyl or quinoxalinyl; X is hydrogen, hydroxy or lower alkyl; andT is hydrogen, halogen, hydroxy, nitro, amino or alkyl,which compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptor. These compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory.
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- CERTAIN PYRROLO PYRIDINE-3-CARBOXAMIDES; A NEW CLASS OF GABA BRAIN RECEPTOR LIGANDS
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The present invention encompasses structures of the formula: STR1 or the pharmaceutically acceptable non-toxic salts thereof wherein: STR2 wherein: W represents substituted or unsubstituted phenyl;X is hydrogen, hydroxy or lower alkyl; T is hydrogen, halogen, hydroxy, nitro, amino or alkyl; R. sub.3 is hydrogen or an organic group;R 4 is hydrogen or substituted or unsubstituted organic substituent;R 5 and R 6 represent organic, and inorganic substituents; andn is 1, 2, 3, or 4, which compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. These compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory.
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- Ruthenium-catalysed synthesis of indoles from anilines and trialkanolamines in the presence of tin(II) chloride dihydrate
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Anilines react with trialkanolamines in dioxane in the presence of a catalytic amount of a ruthenium catalyst together with tin(II) chloride dihydrate to give the corresponding indoles in moderate to good yields.
- Cho, Chan Sik,Lim, Hyo Kyun,Shim, Sang Chul,Kim, Tae Jeong,Choi, Heung-Jin
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p. 995 - 996
(2007/10/03)
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- General and facile synthesis of indoles with oxygen-bearing substituents at the benzene moiety
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Indoles with oxygen-bearing substituents such as a methoxy or (triisopropylsilyl)oxy group at all of the positions of the benzene moiety were synthesized by cyclization of tert-butyl methoxy(or (triisopropylsilyl)oxy)-2-((trimethylsilyl)ethynyl)phenyl)carbamates with potassium tert-butoxide in tert-butyl alcohol. The (ethynylphenyl)carbamates were synthesized by the palladium-catalyzed reaction of (trimethylsilyl)acetylene and the corresponding (iodophenyl)carbamates, which were selectively synthesized by directed lithiation of the phenylcarbamates and subsequent iodination.
- Kondo, Yoshinori,Kojima, Satoshi,Sakamoto, Takao
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p. 6507 - 6511
(2007/10/03)
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- Palladium-Catalyzed Synthesis of Indoles by Reductive N-Heteroannulation of 2-Nitrostyrenes
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A palladium-phosphine catalyzed reductive N-heteroannulation of 2-nitrostyrenes, in the presence of carbon monoxide, producing indoles has been developed. Indoles were obtained, in moderate to excellent yield, from substituted 2-nitrostyrenes having either electron-withdrawing (NO2 and CO2-Me) or electron-donating (Br, OH, Me, OMe, and OTf) substituents on the aromatic ring. Best results were obtained using palladium diacetate (6 mol percent) together with triphenylphosphine (24 mol percent) as the catalytic system, under 4 atm of carbon monoxide in acetonitrile at 70 °C. Other palladium(II) and palladium(0) complexes also catalyze the reaction.
- So?derberg, Bjo?rn C.,Shriver, James A.
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p. 5838 - 5845
(2007/10/03)
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- Certain fused pyrrolecarboxanilides and their use as GABA brain receptor ligands
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The present invention encompasses structures of the formula I: STR1 and the pharmaceutically acceptable non-toxic salts thereof wherein: STR2 wherein:W represents substituted or unsubstituted aryl groups;X is hydrogen, hydroxy or lower alkyl;T is hydrogen, halogen, hydroxyl, amino or alkyl;R 3 is hydrogen or an organic group;R 4 is hydrogen or substituted or unsubstituted organic substituent;R 5 and R 6 represent organic, and inorganic substituents; andn is 1, 2, 3, or 4.These compounds are highly selective agonists, antagonists or inverse agonists for GABAa brain receptors or prodrugs of agonists, antagonists or inverse agonists for GABAa brain receptors. These compounds are useful in the diagnosis and treatment of anxiety, sleep and seizure disorders, overdose with benzodiazepine drugs and for enhancement of memory.
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- Synthesis of the Indole Nucleoside Antibiotics Neosidomycin and SF-2140
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The indole nucleoside antibiotics neosidomycin 5 and SF-2140 3 have been synthesized.Methyl 4-deoxy-2,3-O-isopropylidene-α-D-lyxo-hexopyranoside 8 was converted into methyl 1-chloro-1,4-dideoxy-2,3-di-O-pivaloyl-α-D-lyxo-hexopyranuronate 33 in five steps.Silver(I)-catalysed coupling of compound 33 with 3-(cyanomethyl)indole 20 gave stereoselectively an α-nucleoside which was converted into methyl 1--1,4-dideoxy-α-D-lyxo-hexopyranuronate (neosidomycin, 5).Coupling of compound 33 to 3-cyanomethyl-4-methoxyindole 23 by the sodium salt procedure, and subsequent deacylation, gave methyl 1-(3-cyanomethyl-4-methoxyindol-1-yl)-1,4-dideoxy-α-D-lyxo-hexopyranuronate (SF-2140, 3).Neosidomycin, SF-2140, and their O-acyl derivatives adopt a conformation which differs from that of 1-(6-O-benzoyl-4-deoxy-2,3-O-pivaloyl-α-D-lyxo-hexopyranosyl)-3-(cyanomethyl)indole 29, in which the methyl uronate grouping of the antibiotics is present at a lower oxidation level.
- Buchanan, J. Grant,Stoddart, Jane,Wightman, Richard H.
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p. 1417 - 1426
(2007/10/02)
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- Palladium-Catalyzed Coupling of 2-Bromoanilines with Vinylstannanes. A Regiocontrolled Synthesis of Substituted Indoles
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The palladium-catalyzed cross-coupling reaction of aryl halides and triflates with vinylstannane reagents has been used to produce a variety of substituted indoles.The mild reaction conditions and selectivity inherent in the coupling reaction have been utilized to produce regiochemically pure 4-, 5-, and 6-substituted indoles.
- Krolski, Michael E.,Renaldo, Alfred F.,Rudisill, Duane E.,Stille, J. K.
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p. 1170 - 1176
(2007/10/02)
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- Reactions of Organic Anions, 147.- Simple and General Synthesis of Hydroxy- and Methoxyindoles via Vicarious Nucleophilic Substitution of Hydrogen
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A simple synthesis of 4-, 5-, 6-, and 7-hydroxy- and -methoxyindoles via cyanoalkylation of O-protected nitrophenols by vicarious nucleophilic substitution of hydrogen, followed by catalytic hydrogenation of the (2-nitroaryl)acetonitriles obtained is described.
- Makosza, Mieczyslaw,Danikiewicz, Witold,Wojciechowski, Krzysztof
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p. 203 - 208
(2007/10/02)
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- Silica Gel Assisted Reductive Cyclization of 2-Nitro-β-piperidinostyrenes, Derived from 2-Nitrotoluenes, to Indoles
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An efficient modification of the Leimgruber-Batcho method of indole synthesis has been devised that facilitates the synthesis of a variety of 2,3-unsubstituted indoles containing halogen, methoxy and benzyloxy groups, from 2-nitrotoluenes, in high yields.The modified method involves the condensation of 2-nitrotoluenes with tripiperidinomethane followed by the reductive cyclization of the intermediate 2-nitro-β-piperidinostyrenes with iron and acetic acid in refluxing toluene in the presence of silica gel (column chromatography grade, 60-200 mesh).
- Kawase, Masami,Sinhababu, Achintya K.,Borchardt, Ronald T.
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p. 1499 - 1501
(2007/10/02)
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- SYNTHESIS OF INDOLES FROM N-ARYL-1-ALKENYLSULPHINAMIDES
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Reactions of 1-alkenylmagnesium bromides with N-sulphinyl-benzenamines affords the title sulphinamides 5.On heating in toluene, these sulphonamides 5 are the transformed into the corresponding indoles.
- Baudin, Jean-Bernard,Julia, Sylvestre A.
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p. 837 - 840
(2007/10/02)
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- Some Observations on the Formation of 1-Hydroxyindoles in the Leimgruber-Batcho Indole Synthesis
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The factors influencing the formation of 1-hydroxyindoles in the catalytic hydrogenation of β-dimethylamino-2-nitrostyrenes (Leimgruber-Batcho indole synthesis) have been investigated.Significant amounts of 1-hydroxyindoles were obtained only when the β-dimethylamino-2-nitrostyrene was substituted with an electron-withdrawing group at the 5 or 6 position.The proportion of 1-hydroxyindole formed relative to the normal indole product was found to increase as both the amount of catalyst and hydrogen pressure were decreased.
- Clark, Robin D.,Repke, David B.
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p. 121 - 125
(2007/10/02)
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- Processes for preparing 4-substituted indoles
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A new chemical sequence for preparing indoles is disclosed whose key reactions are reaction of a o-nitrotoluene with tris(dimethylamino)methane to give a β-dimethylamino-o-nitrostyrene which is converted into a semicarbazone and cyclized.
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- HETEROGENEOUS-CATALYTIC E. FISCHER REACTION XIV. EFFECT OF ELECTRONIC FACTORS IN THE HETEROGENEOUS-CATALYTIC E. FISCHER REACTION
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The effect of electronic factors on the heterogeneous-catalytic E.Fischer reaction was studied for the case of methoxy- and nitro-substituted arylhydrazones.It was shown that the presence of the methoxy groups in all probability increases the basicity of the respective hydrazone and facilitates adsorption of the active centers of the catalyst.In this case indoles are obtained with high yields.The presence of nitro groups hinder the adsorption of the hydrazone on the catalyst and as a result leads to a decrease in the yield of indole.
- Suvorov, N. N.,Shkil'kova, V. N.,Podkhalyuzina, N. Ya.
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p. 2117 - 2120
(2007/10/02)
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- Synthesis of Substituted Indoles via Meerwein Arylation
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A new method for the synthesis of substituted indoles is detailed.Meerwein arylation of 4- and 6-substituted 2-nitrobenzenediazonium chlorides with vinyl acetate or vinyl bromide and subsequent reductive cyclization of the resulting adducts affords the corresponding 6- and 4-substituted (CH3, OCH3, Cl, Br, CF3) indoles.The diazonium bisulfates of weakly basic 2-nitroanilines (4-Cl, 6-Br, 4-CF3) gave higher yields of Meerwein arylation adducts than the corresponding diazonium chlorides.Coupling of 2-nitrobenzenediazonium chloride with 2-acetoxy-1-alkenes followed byreductive cyclization affords 2-alkylindoles.
- Raucher, Stanley,Koolpe, Gary A.
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p. 2066 - 2069
(2007/10/02)
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- A SIMPLE PROCEDURE FOR THE PREPARATION OF INDOLES
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Indoles are easily prepared in 60-70percent yield from the corresponding o-nitrotoluenes by condensation with tripiperidinomethane, followed by reductive cyclization with aqueous titanous chloride.
- Lloyd, David H.,Nichols, David E.
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p. 4561 - 4562
(2007/10/02)
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- HETEROGENEOUS-CATALYTIC FISCHER REACTION. 13. CATALYTIC SYNTHESIS OF 4-, 5-, 6-, AND 7-METHOXYINDOLES
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Methoxy-substituted acetaldehyde phenylhydrazones were cyclized in the vapor phase on GIPKh-115 catalyst to give 4-, 5-, 6-, and 7-methoxyindoles. 5-Methoxyindole was obtained in 50percent yield, 4- and 6-methoxyindoles were obtained in 85percent yield, and 7-methoxyindole was obtained in 45percent yield.
- Suvorov, N. N.,Shkil'kova, V. N.,Podkhalyuzina, N. Ya.
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p. 802 - 803
(2007/10/02)
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- SYNTHESIS OF INDOLES FROM N-(TRIFLUOROACETYL)-2-ANILINO ACETALS
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N-(trifluoroacetyl)indoles (3) are produced in high yield from appropriately ring-substituted N-(trifluoroacetyl)-2-anilino acetals (2) in boiling trifluoroacetic acid containing excess trifluoroacetic anhydride.Mild saponification provides the free indoles nearly quantitatively.The scope of the reaction is discussed.The ring closure follows solvolytic substitution of a trifluoroacetoxy group for one of the ethoxy groups in 2.The method has been extended to cyclization of N-(trifluoroacetyl)-α-anilinoacetone in hot polyphosphoric acid followed by saponification to yield 3-methylindole.
- Nordlander, J. Eric,Catalane, David B.,Kotian, Kirtivan D.,Stevens, Randall M.,Haky, Jerome E.
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p. 778 - 782
(2007/10/02)
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- SYNTHESIS OF 4-SUBSTITUTED INDOLES FROM o-NITROTOLUENES
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A facile two- or three-step transformation of o-nitrotoluenes into 4-substituted indoles is described.Treatment of o-nitrotoluenes 1 with DMF acetal, or sometimes more advantageously with tris(N,N-dimethylamino)methane, affords β-(N,N-dimethylamino)styrenes 2 which are readily converted too-nitrophenylacetaldehyde semicarbazones 3 without isolation.Reduction of either 2 or 3 affords 4-substituted indoles 4.Use of the very insoluble semicarbazones results in vastly superior yields of 4 by minimizing completing bimolecular condensation reactions during reduction.This new procedure has been applied to efficiently and conveniently prepare a series of 4-substituted indoles 4.
- Kruse, Lawrence I.
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p. 1119 - 1124
(2007/10/02)
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