- The annular tautomerism of 4(5)-phenylimidazole
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A new polymorph of 4-phenylimidazole 1a has been characterised by X-ray crystallography. Both polymorphs present a secondary structure of chains, and the observed differences in the topology of their crystal packing are related to the conformational diffe
- Claramunt, Rosa M.,Maria, Maria Dolores Santa,Infantes, Lourdes,Cano, Felix H.,Elguero, Jose
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Read Online
- One-step synthesis of imidazoles from Asmic (anisylsulfanylmethyl isocyanide)
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Substituted imidazoles are readily prepared by condensing the versatile isocyanide Asmic, anisylsulfanylmethylisocyanide, with nitrogenous π-electrophiles. Deprotonating Asmic with lithium hexamethyldisilazide effectively generates a potent nucleophile that efficiently intercepts nitrile and imine electrophiles to afford imidazoles. In situ cyclization to the imidazole is promoted by the conjugate acid, hexamethyldisilazane, which facilitates the requisite series of proton transfers. The rapid formation of imidazoles and the interchange of the anisylsulfanyl for hydrogen with Raney nickel make the method a valuable route to mono- and disubstituted imidazoles.
- AlWedi, Embarek,Chao, Allen,Fleming, Fraser F.,Mueller, Louis G.
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supporting information
p. 1499 - 1502
(2021/07/02)
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- Preparation method of 4-phenylimidazole
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The invention discloses a preparation method of 4-phenylimidazole, which comprises the following steps: reacting a compound 1A, a compound 1B and a nitrogen-containing compound to obtain an intermediate; and reacting the intermediate with a reducing agent to obtain a crude product of 4-phenylimidazole, and performing purifying to obtain a refined product of 4-phenylimidazole. According to the preparation method, a reagent with relatively low price is used as a starting raw material, a final product is obtained through two-step reaction, the reaction condition of each step is mild, the yield ofthe obtained 4-phenyl imidazole is high, and the cost can be greatly reduced.
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Paragraph 0049-0053
(2021/01/29)
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- Novel synthesis of N-unsubstituted imidazoles via the cycloaddition of N-(tert-butylsulfinyl)imines and TosMIC
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A facile and efficient method was developed for the synthesis of N-unsubstituted imidazoles via the cycloaddition of N-sulfinyl imines and p-toluenesulfonylmethyl isocyanide (TosMIC). This methodology is operationally simple and useful for the preparation of various aromatic and heteroaromatic imidazoles in good to excellent yields.
- Babu Shubha, Priya,Prasad, Hari,Ramaiah, Manjunatha M.,Shivananju, Nanjunda Swamy
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supporting information
(2020/02/15)
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- LIGHT-EMITTING MATERIAL FOR ORGANIC ELECTROLUMINESCENT DEVICE, ORGANIC ELECTROLUMINESCENT DEVICE USING SAME, AND MATERIAL FOR ORGANIC ELECTROLUMINESCENT DEVICE
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The present invention relates to a novel compound which has the effect of regulating emission wavelengths and has excellent luminescence efficiency; a production method of the novel compound; and an organic electroluminescence device comprising the novel compound. Accordingly, an organic electroluminescence device using a novel pyrene derivative of the present invention may have significantly improved luminescence efficiency and lifetime.COPYRIGHT KIPO 2019
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Paragraph 0147-0152
(2019/05/25)
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- Preparation of Imidazole Derivatives via Bisfunctionalization of Alkynes Catalyzed by Ruthenium Carbonyl
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A one-step, oxidative bisfunctionalization of alkynes to generate cis -enediol diacetates catalyzed by ruthenium carbonyl (triruthenium dodecacarbonyl) is presented. The reaction was performed using the alkyne, (diacetoxyiodo)benzene, Ru 3 (CO) 12 as the catalyst, and toluene as the solvent at 100 °C to give the cis -enediol diacetates in up to 82percent yields. This method overcomes the shortcomings of existing methods, such as tedious reaction steps, substrate limitations, and the use of toxic reagents. Furthermore, the reaction of module cis -enediol diacetates with ammonium carbonate [(NH 4) 2 CO 3 ] in an alcohol solvent gave imidazole derivatives in 37-84percent yields, thus providing a simple and mild new method for the synthesis of imidazole compounds.
- Chen, Yue-Peng,Gu, Ling-Hui,He, Ling,Luo, Yang,Ruan, Yi-Tong,Yang, Ze
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p. 3520 - 3528
(2019/09/07)
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- Palladium catalyzed hydrodefluorination of fluoro-(hetero)arenes
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Palladium catalyzed hydrodefluorination was developed for fine-tuning the properties of fluoro-(hetero)aromatic compounds. The robust reaction can be set up in air, requires only commercially available components, and tolerates a variety of heterocycles and functionalities relevant to drug discovery. Given the prevalence of fluorine incorporation around metabolic hotspots, the corresponding deuterodefluorination reaction may prove useful for converting fluorinated libraries to deuterated analogues to suppress the oxidative metabolism by kinetic isotope effects.
- Gair, Joseph J.,Grey, Ronald L.,Giroux, Simon,Brodney, Michael A.
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supporting information
p. 2482 - 2487
(2019/04/10)
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- One-pot synthesis of 2-alkyl-4(5)-aryl-1H-imidazoles from 1-aryl-2-bromoethanones, ammonium carbonate and aliphatic carboxylic acids
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A simple and efficient protocol for the preparation of 2-alkyl-4(5)-aryl- 1H-imidazoles starting from α-bromo aryl methyl ketones and aliphatic carboxylic acids in the presence of ammonium carbonate has been developed.
- Liu, Cong,Nie, Yijiao,Yao, Guowei,Dai, Rongji,Deng, Yulin
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p. 208 - 210
(2014/05/06)
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- Suzuki-Miyaura cross-coupling reactions of unprotected haloimidazoles
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An efficient protocol for the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of unprotected haloimidazoles is reported. The relatively mild reaction conditions allow for ready access to a wide array of functionalized imidazole derivatives in good to excellent yields. The synthetic utility of this method is demonstrated by the total synthesis of nortopsentin D.
- Tan, Jiajing,Chen, Yonggang,Li, Hongmei,Yasuda, Nobuyoshi
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p. 8871 - 8876
(2015/01/08)
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- A three-way switchable process for suzuki cross-coupling, hydrodehalogenation, or an assisted tandem hydrodehalogenation and suzuki cross-coupling sequence
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A three-way switchable Pd-catalyzed and microwave assisted process appropriate for selective arylation or hydrodehalogenation of the imidazole backbone was discovered and entirely optimized. The "arylation switch position" was adapted and optimized for the synthesis of 4,5-diaryl-1H-imidazoles, while the "hydrodehalogenation switch position" was used for the preparation of 4(5)-iodo-1H-imidazole. The hydrodehalogenation and the cross-coupling reactions were also successfully combined in "the third switch position" that performs an assisted tandem reaction sequence that produced 4(5)-aryl-1H-imidazole. All of the three pathways produced their corresponding products in excellent yield. Copyright
- Sandtorv, Alexander H.,Bjorsvik, Hans-Rene
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supporting information
p. 3231 - 3243
(2013/12/04)
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- GLUCAGON RECEPTOR MODULATORS
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The present invention provides a compound of Formula (I) or a pharmaceutically acceptable salt thereof wherein R1, R2, R3, A1, A2, A3, A4, L, B1, B2, B3 and B4 are as defined herein. The compounds of Formula I have been found to act as glucagon antagonists or inverse agonists. Consequently, the compounds of Formula I and the pharmaceutical compositions thereof are useful for the treatment of diseases, disorders, or conditions mediated by glucagon.
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Page/Page column 36
(2012/08/27)
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- Facile structural elucidation of imidazoles and oxazoles based on NMR spectroscopy and quantum mechanical calculations
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The reaction of 1,2,3-tricarbonyl derivatives with hexamethylenetetramine and ammonium acetate in acetic acid provides an unambiguous approach to the synthesis of imidazoles, whereas the Bredereck reaction of α-haloketones in formamide, yields both imidazoles and oxazoles. Herein we describe a facile methodology for distinguishing between these heterocyclic compounds based on a combination of NMR spectroscopy and quantum mechanical calculations. In the NMR data the oxazole C-2 has a chemical shift of ca. 150 ppm whereas in the imidazoles it is found at ca. 135 ppm, with a 1JC-H of ca. 250 Hz for the oxazoles and ca. 210 Hz for the imidazoles. 1JC-H values can be easily obtained from a gated-decoupled 13C spectrum, and even more trivially, from the separation of the H-2 13C satellites in the 1H spectra. Additionally, the computed NMR data, obtained from density functional theory, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products of the Bredereck reaction.
- Weitman, Michal,Lerman, Lena,Cohen, Shmuel,Nudelman, Abraham,Major, Dan T.,Gottlieb, Hugo E.
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scheme or table
p. 1465 - 1471
(2010/04/04)
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- Synthesis of 4,5-substituted imidazoles by a fast condensation of 1,2-diketones and urotropine in heterogeneous medium
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Starting from 1,2-diketones and urotropine in the presence of ammonium acetate, a simple and efficient solventless microwave-assisted synthesis of 4,5-disubstituted imidazoles was accomplished. Georg Thieme Verlag Stuttgart.
- Bratulescu, George
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experimental part
p. 2319 - 2320
(2010/02/28)
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- TRIAZINE COMPOUNDS AS KINASE INHIBITORS
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The present invention relates to triazine compounds that are useful as kinase inhibitors. More particularly, the present invention relates to morpholino substituted triazines, methods for their preparation, pharmaceutical compositions containing these compounds and uses of these compounds in the treatment of proliferative disorders. These compounds may be useful as medicaments for the treatment of a number of proliferative disorders including tumours and cancers as well as other disorders or conditions related to or associated with mTOR kinases or PI3 kinases. The compounds are of the formula (I)
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Page/Page column 97
(2009/09/05)
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- Highly selective synthesis of 4(5)-aryl-, 2,4(5)-diaryl-, and 4,5-diaryl-1H-imidazoles via Pd-catalyzed direct C-5 arylation of 1-benzyl-1H-imidazole
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Highly selective, practical, and efficient protocols for the preparation of 4(5)-aryl-1H-imidazoles 2, 2,4(5)-diaryl-1H-imidazoles 3, and 4,5-diaryl-1H-imidazoles 1 are described. A key step of these protocols is the regioselective synthesis of 5-aryl-1-benzyl-1H-imidazoles 9 by Pd-catalyzed direct C-5 arylation of commercially available 1-benzyl-1H-imidazole (8) with aryl halides. The three-step synthesis of compounds 3 from 8 also involves the Pd-catalyzed and Cu-mediated direct C-2 arylation of imidazoles 9 with aryl halides under base-free and ligandless conditions. On the other hand, the four-step synthesis of imidazoles 1 from 8 also involves the regioselective bromination of compounds 9 and a Suzuki reaction of the resulting 5-aryl-1-benzyl-4-bromo-1H-imidazoles 11 with arylboronic acids 5 under phase-transfer conditions, followed by N-debenzylation.
- Bellina, Fabio,Cauteruccio, Silvia,Di Fiore, Annarita,Marchetti, Chiara,Rossi, Renzo
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p. 6060 - 6072
(2008/12/20)
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- A new boronic-acid based strategy to synthesize 4(5)-(het)aryl-1H-imidazoles
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This paper describes the synthesis of a new N-THP protected 5-(1H)-imidazolyl boronic acid pinacol ester and its use in Suzuki cross-coupling reactions with a wide range of (het)aryl halides to provide 4(5)-(het)aryl-1H-imidazoles.
- Primas, Nicolas,Mahatsekake, Clément,Bouillon, Alexandre,Lancelot, Jean-Charles,Oliveira Santos, Jana Sopkovà-de,Lohier, Jean-Fran?ois,Rault, Sylvain
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p. 4596 - 4601
(2008/09/20)
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- Efficient and practical synthesis of 4(5)-aryl-1H-imidazoles and 2,4(5)-diaryl-1H-imidazoles via highly selective palladium-catalyzed arylation reactions
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(Chemical Equation Presented) 4(5)-Aryl-1H-imidazoles can be efficiently and selectively prepared by PdCl2(dppf)-catalyzed Suzuki-Miyaura reaction of commercially available 4(5)-bromo-1H-imidazole with arylboronic acids under phase-transfer conditions. On the other hand, N-unprotected 4(5)-aryl-1H-imidazoles can undergo highly selective Pd(OAc)2- catalyzed and CuI-mediated direct C-2-arylation with a variety of aryl bromides and iodides under base-free and ligandless conditions to produce 2,4(5)-diaryl-1H-imidazoles in modest to good yields. No N-arylation byproducts are observed under the experimental conditions used to prepare 2,4(5)-diaryl-1H-imidazoles.
- Bellina, Fabio,Cauteruccio, Silvia,Rossi, Renzo
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p. 8543 - 8546
(2008/03/11)
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- Direct palladium-catalyzed C-2 and C-3 arylation of indoles: A mechanistic rationale for regioselectivity
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We have recently developed palladium-catalyzed methods for direct arylation of indoles (and other azoles) wherein high C-2 selectivity was observed for both free (NH)-indole and (NR)-indole. To provide a rationale for the observed selectivity ("nonelectrophilic" regioselectivity), mechanistic studies were conducted, using the phenylation of 1-methylindole as a model system. The reaction order was determined for iodobenzene (zero order), indole (first order), and the catalyst (first order). These kinetic studies, together with the Hammett plot, provided a strong support for the electrophilic palladation pathway. In addition, the kinetic isotope effect (KIEH/D) was determined for both C-2 and C-3 positions. A surprisingly large value of 1.6 was found for the C-3 position where the substitution does not occur (secondary KIE), while a smaller value of 1.2 was found at C-2 (apparent primary KIE). On the basis of these findings, a mechanistic interpretation is presented that features an electrophilic palladation of indole, accompanied by a 1,2-migration of an intermediate palladium species. This paradigm was used to design new catalytic conditions for the C-3 arylation of indole. In case of free (NH)-indole, regioselectivity of the arylation reaction (C-2 versus C-3) was achieved by the choice of magnesium base.
- Lane, Benjamin S.,Brown, Meghann A.,Sames, Dalibor
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p. 8050 - 8057
(2007/10/03)
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- Process for the synthesis of imidazoles
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The present invention provides a process for the preparation of imidazoles by reacting a cyano compound with a silylalkylisocyanide compound. Such imidazoles are useful pharmacologically-active compounds and/or intermediates for the preparation of pharmacologically-active compounds.
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Page/Page column 6
(2008/06/13)
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- Selective C-arylation of free (NH)-heteroarenes via catalytic C-H bond functionalization
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A new system for palladium-catalyzed arylation of a broad spectrum of free (NH)-heteroarenes has been developed (indole, pyrrole, pyrazole, 2-phenylimidazole, imidazole, benzimidazole, and purine). Remarkable selectivity has been achieved in the presence of MgO base, providing single C-arylation products, while no N-arylation and no bis-arylation products have been detected. In the case of free imidazole, exclusive C-4 arylation may be switched to exclusive 2-arylation by the addition of CuI to the Pd/Ph3P/MgO system. When free aryl-(NH)-azoles are desired, direct arylation eliminates three steps in comparison to standard methods, including N-protection, stoichiometric metalation or halogenation, and N-deprotection. Copyright
- Sezen, Bengue,Sames, Dalibor
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p. 5274 - 5275
(2007/10/03)
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- Cobalt-catalyzed arylation of azole heteroarenes via direct C-H bond functionalization
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(Equation presented) We herein report a new cobalt-catalyzed method for arylation of azole heteroarenes, including thiazole, oxazole, imidazole, benzothiazole, benzoxazole, and benzimidazole. The direct arylation of thiazole and oxazole was achieved both with iodo- and bromoarenes as the aryl donors in the presence of cobalt catalyst [Co(OAc)2/IMes] and cesium carbonate, while imidazole required the use of zinc oxide as the base. A complete reversal of arylation from C-5 to C-2 was accomplished using the bimetallic Co/Cu/IMes system. A direct comparison of the new cobalt method and the previously developed palladium protocol revealed significant differences, in terms of both chemical yield and selectivity.
- Sezen, Bengue,Sames, Dalibor
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p. 3607 - 3610
(2007/10/03)
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- Highly chemoselective trichloroacetimidate-mediated alkylation of ascomycin: A convergent, practical synthesis of the immunosuppressant L- 733,725
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L-733,725, a new immunosuppressant drug candidate, was prepared by a highly chemoselective alkylation of the macrolide ascomycin at the C32 hydroxy position with the imidazolyl trichloroacetimidate 16. The trichloroacetimidate-activated side chain 16 was prepared by an efficient fourstep sequence in 42% overall yield. The high chemoselectivity in the alkylation of the C32 hydroxy group of the unprotected ascomycin was the result of the synergetic effects of the electron-donating protecting group on the imidazole 16, the polar, moderately basic solvent, and the strong acid catalyst. N,N-Dimethylpivalamide mixed with acetonitrile was found to be the best solvent and trifluromethanesulfonic acid the best catalyst. This synthesis coupled with a resin column purification of L-733,725 followed by crystallization of its tartrate salt has been used to make multikilogram quantities of the bulk drug with consistent and high purity.
- Song, Zhiguo,DeMarco, Anthony,Zhao, Mangzhu,Corley, Edward G.,Thompson, Andrew S.,McNamara, James,Li, Yulan,Rieger, Dale,Sohar, Paul,Mathre, David J.,Tschaen, David M.,Reamer, Robert A.,Huntington, Martha F.,Ho, Guo-Jie,Tsay, Fuh-Rong,Emerson, Khateeta,Shuman, Richard,Grabowski, Edward J. J.,Reider, Paul J.
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p. 1859 - 1867
(2007/10/03)
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- Novel synthesis of 4(5)-monosubstituted imidazoles via cycloaddition of tosylmethyl isocyanide to aldimines
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4(5)-Monosubstituted imidazoles (9) have been prepared via base-induced cycloaddition of tosylmethyl isocyanide (TosMIC) to N-(dimethylsulfamoyl)aldimines (2) or N-tosylaldimines (3). In the first case, N-(dimethylsulfamoyl)imidazoles 8 are the initial reaction products, from which the dimethylsulfamoyl group is readily removed with aqueous HBr. In the second case, the tosyl group of 1-tosylimidazoles 10 is lost spontaneously to give 4(5)-monosubstituted imidazoles 9 in one operation.
- Ten Have, Ronald,Huisman, Marco,Meetsma, Auke,Van Leusen, Albert M.
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p. 11355 - 11368
(2007/10/03)
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- A Two-Step Synthesis of Imidazoles from Aldehydes via 4-Tosyloxazolines
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Imidazoles with substituents in the 4- and 4,5-positions were prepared by heating 4-tosyloxazolines in saturated methanolic ammonia.Similar treatment of these oxazolines with monoalkylamines regioselectively affords 1,4-disubstituted imidazoles.When oxazolines bearing an ethyl group at the 4-position were heated with alkylamines, however, a regioisomeric mixture of di- or trisubstituted imidazoles was produced.These reactions proceed via an intermolecular condensation of α-amino ketones and amidines or intramolecular cyclization of α-amidino ketone intermediates, respectively.
- Horne, David A.,Yakushijin, Kenichi,Buechi, George
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p. 139 - 154
(2007/10/02)
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- Novel synthesis of N-unsubstituted imidazoles using N-trimethylsilylimines
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Cycloaddition of N-trimethylsilylimines 3 with the lithiotosylmethylisocyanates 4 is described. This provides a novel synthesis of 4-substituted and 4,5-disubstituted imidazoles from easily accessible aldehydes or organolithium reagents, under mild conditions and in a one-pot operation.
- Shih
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p. 595 - 598
(2007/10/02)
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- Dehydrogenation of Imidazolines to Imidazoles with Pd-Carbon
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A new and mild method for converting imidazoline derivatives to imidazole derivatives using Pd-C is described.The dehydrogenation of 2- and 2,4-disubstituted imidazolines is carried out in refluxing toluene using Pd-C in good yields.Mixed results are obtained with 4-substuted imidazolines.
- Amemiya, Yoshiya,Miller, Duane D.,Hsu, Fu-Lian
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p. 2483 - 2489
(2007/10/02)
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- CONVENIENT SYNTHESIS OF 2-THIONAPHTHYLMETHYL ISOCYANIDE: A USEFUL REAGENT FOR METHYL ISOCYANIDE TRANSFER
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The crystalline 2-thionaphthylmethyl isocyanide (1), prepared from the novel N-(formamidomethyl)-N-benzyl morpholinium iodide (2), via transfer of elements of CH2NHCHO, is totally devoid of pervasive odour.The cyclo-addition of the conjugate base of (1) to nitriles followed by desulfurization, under very mild conditions, provides an attractive route to imidazoles.
- Ranganathan, S.,Singh, W. P.
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p. 1435 - 1436
(2007/10/02)
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- CARBENIC REACTIONS OF 4-DIAZO-4H-IMIDAZOLE WITH BENZENE DERIVATIVES
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The electrophilic behavior of 4H-imidazolylidene is greatly modified by coordinating groups in benzene derivatives undergoing substitution.
- Amick, T. J.,Shechter, H.
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p. 901 - 904
(2007/10/02)
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- A NEW SYNTHESIS OF UNSUBSTITUTED, 4(5), AND 4,5-SUBSTITUTED 1H-IMIDAZOLES.
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Novel synthesis of the title compounds based on the reaction of N-(aminomethyl) benzamide with 1,2-dicarbonyl compounds is described.
- Khalaj, A.,Ghafari, M.
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p. 5019 - 5020
(2007/10/02)
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- OXIDATION OF 2,4-DISUBSTITUTED PYRIMIDINES WITH ORGANIC PERACIDS
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While 4,6-disubstituted (alkyl, aryl, alkoxyl) pyrimidines easily afforded the corresponding mono-N-oxides with hydrogen peroxide in glacial acetic acid, pyrimidine derivatives whose 6-position is free, are partly oxidatively degradated during N-oxidation reaction.The oxidation of the latter compounds under the above conditions gave 2,4-disubstituted imidazoles together with their mono-N-oxides.A likely mechanism of this ring-contraction and the improved conditions for the synthesis of the N-oxides are also described.
- Yamanaka, Hiroshi,Ogawa, Shigeru,Sakamoto, Takao
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p. 573 - 576
(2007/10/02)
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