- Method for preparing amine compound by reducing amide compound
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The invention relates to a method for preparing an amine compound by reducing an amide compound, which comprises the following steps: in a protective atmosphere, mixing the amide compound or cyclic amide, a zirconium metal catalyst and pinacol borane, carrying out amide reduction reaction at room temperature, and carrying out aftertreatment by using an ether solution of hydrogen chloride after 12-48 hours to obtain an amine hydrochloride compound. The method is simple to operate, low in cost, good in functional group tolerance and wide in substrate range.
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Paragraph 0253-0255
(2021/02/10)
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- Cycloheptylamine derivatives as anti-diabetic agents
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Cycloalkylamine derivatives may be used for preventing or treating diseases in humans, animals, and have demonstrated efficacy specifically in treating type 2 diabetes. In an embodiment, the cycloalkylamine derivatives can include a compound selected from the group consisting of cycloheptanamine salts, cyclohexanamine salts, cyclopentanamine salts 1-cycloheptyl-[4,4′-bipyridin]-1-ium, N1,N2-dicycloheptyloxalamide, 1-[3′,5′-bis(trifluoromethyl)phenyl]-3-cycloheptylurea, 1,1′-(4-methyl-1,3-phenylene)bis(3-cycloheptylurea), 1-(2′-aminopyrimidin-4′-yl)-3-cycloheptylurea, 4-amino-N-(cycloheptylcarbamoyl)benzenesulfonamide, 4-(3′-cycloheptylureido)-N-(5″-methylisoxazol-3″-yl)benzenesulfonamide, N-(cycloheptylcarbamoyl)-4-methylbenzenesulfonamide, 1-cycloheptylguanidine hydrochloride, (E)-amino[(amino(cycloheptylamino)methylene)amino]methaniminium chloride, or a pharmaceutically acceptable salt thereof.
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Page/Page column 7; 8
(2021/08/18)
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- One-Pot Synthesis of Primary and Secondary Aliphatic Amines via Mild and Selective sp3 C?H Imination
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The direct replacement of sp3 C?H bonds with simple amine units (?NH2) remains synthetically challenging, although primary aliphatic amines are ubiquitous in medicinal chemistry and natural product synthesis. We report a mild and selective protocol for preparing primary and secondary aliphatic amines in a single pot, based on intermolecular sp3 C?H imination. The first C?H imination of diverse alkanes, this method shows useful site-selectivity within substrates bearing multiple sp3 C?H bonds. Furthermore, this reaction tolerates polar functional groups relevant for complex molecule synthesis, highlighted in the synthesis of amine pharmaceuticals and amination of natural products. We characterize a unique C?H imination mechanism based on radical rebound to an iminyl radical, supported by kinetic isotope effects, stereoablation, resubmission, and computational modeling. This work constitutes a selective method for complex amine synthesis and a new mechanistic platform for C?H amination.
- Comito, Robert J.,Ghosh, Subrata K.,Hu, Mengnan
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supporting information
p. 17601 - 17608
(2021/11/03)
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- Green method for catalyzing reduction reaction of aliphatic nitro derivative
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The invention relates to a green method for catalyzing reduction reaction of aliphatic nitro derivatives. According to the method, non-transition metal compounds, namely triethyl boron and potassium tert-butoxide, are used as a catalytic system for the first time, an aliphatic nitro derivative and pinacolborane which is low in price and easy to obtain are catalyzed to be subjected to a reduction reaction under mild conditions, and an aliphatic amine hydrochloride product is synthesized after acidification with a hydrochloric acid aqueous solution. Compared with a traditional method, the method generally has the advantages that the catalyst is cheap and easy to obtain, operation is convenient, and reaction is safe. The selective reduction reaction of the aliphatic nitro derivative catalyzed by the non-transition metal catalyst and pinacol borane is realized for the first time, and the aliphatic amine hydrochloride product is synthesized through acidification treatment of the hydrochloric acid aqueous solution, so that a practical new reaction strategy is provided for laboratory preparation or industrial production.
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Paragraph 0005-0006; 0045-0048
(2021/07/31)
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- Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
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Transition metal catalysis that utilizes N-heterocyclic carbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for the retention of various reducible functionalities and the compatibility of sensitive groups toward hydroboration, thereby providing a mild, chemoselective, and facile strategy to form anilines, as well as heteroaryl and aliphatic amine derivatives, with broad scope and particularly high turnover numbers (up to 1.8 × 106). Mechanistic studies, based on theoretical calculations, indicate that the CAAC ligand plays an important role in promoting polarity reversal of hydride of HBpin; it serves as an H-shuttle to facilitate deoxygenative hydroboration. The preparation of several commercially available pharmaceuticals by means of this strategy highlights its potential application in medicinal chemistry.
- Zhao, Lixing,Hu, Chenyang,Cong, Xuefeng,Deng, Gongda,Liu, Liu Leo,Luo, Meiming,Zeng, Xiaoming
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supporting information
p. 1618 - 1629
(2021/01/25)
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- Ceria supported Ru0-Ruδ+ clusters as efficient catalyst for arenes hydrogenation
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Selective hydrogenation of aromatic amines, especially chemicals such as aniline and bis(4-aminocyclohexyl)methane for non-yellowing polyurethane, is of particular interests due to the extensive applications. To conquer the existing difficulties in selective hydrogenation, the Ru0-Ruδ+/CeO2 catalyst with solid frustrated Lewis pairs was developed for aromatic amines hydrogenation with excellent activity and selectivity under relative milder conditions. The morphology, electronic and chemical properties, especially the Ru0-Ruδ+ clusters and reducible ceria were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS), CO2 temperature programmed desorption (CO2-TPD), H2 temperature programmed reduction (H2-TPR), H2 diffuse reflectance Fourier transform infrared spectroscopy (H2-DRIFT), Raman, etc. The 2% Ru/CeO2 catalyst exhibited good conversion of 95% and selectivity greater than 99% toward cyclohexylamine. The volcano curve describing the activity and Ru state was found. Owning to the “acidic site isolation” by surrounding alkaline sites, condensation between the neighboring amine molecules could be effectively suppressed. The catalyst also showed good stability and applicability for other aromatic amines and heteroarenes containing different functional groups.
- Cao, Yanwei,Zheng, Huan,Zhu, Gangli,Wu, Haihong,He, Lin
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supporting information
p. 770 - 774
(2020/08/24)
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- Metal-Free Synthesis of Heteroaryl Amines or Their Hydrochlorides via an External-Base-Free and Solvent-Free C-N Coupling Protocol
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Herein, a metal-free and solvent-free protocol was developed for the C-N coupling of heteroaryl halides and amines, which afforded numerous heteroaryl amines or their hydrochlorides without any external base. Further investigations elucidated that the basicity of amines and specific interactions derived from the X-ray crystallography analysis of 3j′·HCl played pivotal roles in the reactions. Moreover, this protocol was scalable to gram scales and applicable to drug molecules, which demonstrated its practical value for further applications.
- Fan, Guang-Gao,Jiang, Bo-Wen,Sang, Wei,Cheng, Hua,Zhang, Rui,Yu, Bao-Yi,Yuan, Ye,Chen, Cheng,Verpoort, Francis
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p. 14627 - 14639
(2021/11/01)
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- Cerium-Catalyzed C-H Functionalizations of Alkanes Utilizing Alcohols as Hydrogen Atom Transfer Agents
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Modern photoredox catalysis has traditionally relied upon metal-to-ligand charge-transfer (MLCT) excitation of metal polypyridyl complexes for the utilization of light energy for the activation of organic substrates. Here, we demonstrate the catalytic application of ligand-to-metal charge-transfer (LMCT) excitation of cerium alkoxide complexes for the facile activation of alkanes utilizing abundant and inexpensive cerium trichloride as the catalyst. As demonstrated by cerium-catalyzed C-H amination and the alkylation of hydrocarbons, this reaction manifold has enabled the facile use of abundant alcohols as practical and selective hydrogen atom transfer (HAT) agents via the direct access of energetically challenging alkoxy radicals. Furthermore, the LMCT excitation event has been investigated through a series of spectroscopic experiments, revealing a rapid bond homolysis process and an effective production of alkoxy radicals, collectively ruling out the LMCT/homolysis event as the rate-determining step of this C-H functionalization.
- An, Qing,Chen, Yuegang,Liu, Weimin,Pan, Hui,Wang, Xin,Wang, Ziyu,Zhang, Kaining,Zuo, Zhiwei
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supporting information
p. 6216 - 6226
(2020/04/27)
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- Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions?
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Hydrogenation of over a dozen aromatic compounds, including both heteroarenes and arenes, over palladium on carbon (Pd/C, 1–100 molpercent) with H2-balloon pressure at room temperature is reported. Analyses using pyridine as a model substrate revealed that acetic acid was the best solvent, as using only 1 molpercent Pd/C provided piperidine quantitatively. Substrate scope analysis and density functional theory calculations indicated that reaction rates are highly dependent on frontier molecular orbital characteristics and the steric bulkiness of substituents. Moreover, the established method was used for the concise synthesis of the anti-Alzheimer drug donepezil (Aricept?).
- Tanaka, Nao,Usuki, Toyonobu
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p. 5514 - 5522
(2020/07/24)
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- Mild N-deacylation of secondary amides by alkylation with organocerium reagents
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Secondary amides are a class of highly stable compounds serving as versatile starting materials, intermediates and directing groups (amido groups) in organic synthesis. The direct deacylation of secondary amides to release amines is an important transformation in organic synthesis. Here, we report a protocol for the deacylation of secondary amides and isolation of amines. The method is based on the activation of amides with Tf2O, followed by addition of organocerium reagents, and acidic work-up. The reaction proceeded under mild conditions and afforded the corresponding amines, isolated as their hydrochloride salts, in good yields. In combination with the C-H activation functionalization methodology, the method is applicable to the functionalization of aniline as well as conversion of carboxylic derivatives to functionalized ketones.
- Wang, Ai-E.,Chang, Zong,Liu, Yong-Peng,Huang, Pei-Qiang
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supporting information
p. 1055 - 1058
(2015/09/01)
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- Direct Preparation of Amides from Amine Hydrochloride Salts and Orthoesters: A Synthetic and Mechanistic Perspective
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The conversion of a wide range of primary and secondary aliphatic and a few arylamine hydrochloride salts to their corresponding acetamides with trimethyl orthoacetate is described. Mechanistic studies using NMR and gas chromatography-mass spectrometry techniques indicate these reactions proceed via an O-methylimidate intermediate that undergoes in situ demethylation by chloride, affording the corresponding acetamides. Synthetically, this reaction represents a practical, high-yielding protocol with a simple workup for the rapid conversion of amine hydrochloride salts to acetamides.
- Di Grandi, Martin J.,Bennett, Caitlin,Cagino, Kristen,Muccini, Arnold,Suraci, Corey,Saba, Shahrokh
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supporting information
p. 2601 - 2607
(2015/11/28)
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- A remarkable one-pot sequential four-component synthesis of tetrahydroquinazolines via an isocyanide-based multicomponent reaction
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A novel one-pot sequential four-component strategy has been developed for the synthesis of tetrahydroquinazolines using either an aliphatic or an acyl halide, an isocyanide, and a 1,3-diamine, in methanol at 60 °C, in good to moderate yields without using a catalyst. Georg Thieme Verlag Stuttgart, New York.
- Shaabani, Ahmad,Mahyari, Mojtaba,Aghaei, Morteza,Keshipour, Sajjad,Ng, Seik Weng
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p. 1968 - 1972
(2013/09/24)
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- Hydrazine-mediated reduction of nitro and azide functionalities catalyzed by highly active and reusable magnetic iron oxide nanocrystals
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Iron oxide (Fe3O4) nanocrystals generated in situ from an inexpensive and readily available iron source catalyze the reduction of nitroarenes to anilines with unparalleled efficiency. The procedure is chemoselective, avoids the use of precious metals, and can be applied under mild reflux conditions (65 or 80 C) or using sealed vessel microwave heating in an elevated temperature regime (150 C). Utilizing microwave conditions, a variety of functionalized anilines have been prepared in nearly quantitative yields within 2-8 min at 150 C, in a procedure also successfully applied to the reduction of aliphatic nitro compounds and azides. The iron oxide nanoparticles are generated in a colloidal form, resulting in homogeneous solutions suitable for continuous flow processing. Selected examples of anilines of industrial importance have been prepared in a continuous regime using this protocol.
- Cantillo, David,Moghaddam, Mojtaba Mirhosseini,Kappe, C. Oliver
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p. 4530 - 4542
(2013/06/05)
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- A catalytic version of hypervalent aryl-λ3-iodane-induced Hofmann rearrangement of primary carboxamides: Iodobenzene as an organocatalyst and m-chloroperbenzoic acid as a terminal oxidant
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The first catalytic version of hypervalent aryl-λ3- iodane-induced Hofmann rearrangement of primary carboxamides, which probably involves in situ generation of a tetracoordinated bis(aqua)(hydroxy)phenyl- λ3-iodane complex as an active oxidant from a catalytic amount of iodobenzene by the reaction with m-chloroperbenzoic acid in the presence of HBF4 in dichloromethane-water under mild conditions, was developed.
- Miyamoto, Kazunori,Sakai, Yuuta,Goda, Shunsuke,Ochiai, Masahito
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supporting information; experimental part
p. 982 - 984
(2012/02/04)
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- Photochemical molecular storage of Cl2, HCl, and COCl 2: Synthesis of organochlorine compounds, salts, ureas, and polycarbonate with photodecomposed chloroform
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Chloroform is available as not only an organic solvent but also photochemical molecular storage for synthetically important chemicals such as Cl2, HCl, and COCl2. We have succeeded in synthesizing organochlorine compounds, hydrochloric salt of amines, ureas, organic carbonates, and polycarbonate in practical high yields with photodecomposed chloroform.
- Kuwahara, Yuki,Zhang, Ailing,Soma, Haruka,Tsuda, Akihiko
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supporting information; experimental part
p. 3376 - 3379
(2012/08/08)
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- Deep cavitand receptors with pH-independent water solubility
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Pendant oligoethyleneglycol groups confer water solubility to a cavitand over a wide pH range. The kinetic stability of the host-guest complexes reveals an effective stabilization through hydrogen bonding even in the highly competitive aqueous environment.
- Lledo, Agusti,Rebek Jr., Julius
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supporting information; body text
p. 8630 - 8632
(2011/01/04)
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- Retro-diels-alder reactions of masked cyclopentadienones catalyzed by heterogeneous Bronsted acids
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The zeolite H-Beta catalyzes the retro-Diels-Alder reaction of a range of cyclopentadiene cyclo-adducts at moderate temperatures and ambient pressure, in the presence of an active dienophile. The active catalyst was identified and optimum reaction conditions established after screening a range of zeolites in the retro-Diels-Alder reaction of the cyclopentadiene adduct of cyclopentenone. Our results suggest that retro-Diels-Alder reactions of tricyclodecadienones are catalyzed by Bronsted acids and the high catalytic performance of H-Beta catalysts can be ascribed to the optimal balance between the number of acid sites and their strength as well as to the accessibility of these sites. The methodology was then applied to a series of alkyl derivatives of cyclopentadienylcyclopentenones to provide a viable alternative synthetic route to 4-alkylcyclopentenones and the versatility of the approach was demonstrated by the successful cycloreversion of N-cyclohexyl-2-azanorborn-5-ene. Copyright
- Demuynck, Anneleen L. W.,Levecque, Pieter,Kidane, Aklilu,Gammon, David W.,Sickle, Eugene,Jacobs, Pierre A.,De Vos, Dirk E.,Sels, Bert F.
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experimental part
p. 3419 - 3430
(2011/02/23)
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- Aminomethylene functional siloxanes
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Organopolysiloxanes containing pendent silicon-bonded aminomethylene groups may be prepared by reaction of hydroxy-functional siloxanes or polysiloxanes with aminomethylalkoxysilanes. By adjusting the functionalities of the siloxane and silane, branched siloxanes with aminomethylene functionality may be obtained, as may also organopolysiloxanes of high amine number, reflecting numerous chain-pendent aminomethylene groups. The products are easily emulsifyable in water.
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Page/Page column 3
(2010/11/08)
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- Synthesis of primary amines by the electrophilic amination of Grignard reagents with 1,3-dioxolan-2-one O-sulfonyloxime
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(Chemical equation presented) Primary amines are prepared by the electrophilic amination of Grignard reagents with 4,4,5,5-tetramethyl-1,3- dioxolan-2-one O-phenylsulfonyloxime and the acidic hydrolysis of the resulting imines.
- Kitamura, Mitsuru,Suga, Takahiro,Chiba, Shunsuke,Narasaka, Koichi
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p. 4619 - 4621
(2007/10/03)
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- Synthesis, spectral characterization and crystal structures of organophosphonic diamides: Pyramidal nitrogen centers and hydrogen bonding in [PhP(O)(NHtBu)2], [PhP(O)(NHDipp)2] (Dipp = 2,6-iPr2C6H3) and [tBuP(O)(NHiPr)2]
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Organophosphonic diamides of general formula [R1P(O)(NHR2)2] (1-8; R1 = Ph, Cy or tBu and R2 = Cy, iPr, tBu or Dipp) have been prepared by the addition of P,P′-dichloro(alkyl/aryl)phosphine oxide, R1P(O)Cl2, to a solution of primary amine in toluene. The synthesis of PhP(O)(NHtBu)2 (1) in high yield was achieved by slow oxidation of PhP(NHtBu)2 in air over several days. All new compounds have been characterized by elemental analysis and by IR, EI mass and NMR (1H and 31P) spectroscopy. The molecular structures of [PhP(O)(NHtBu)2] (1), [PhPO(NHDipp)2] (2) and [tBuP(O)(NHiPr)2] (7) have been determined by single crystal X-ray diffraction studies. The amido nitrogen atoms in 1, 2 and 7 show considerable deviation from the expected trigonal-planar geometry. The observed dihedral angles and the orientation of the nitrogen lone pair (l.p.) in these compounds point to the role of l.p.(N) → σ*(P-X) type negative hyperconjugative interactions in P-N multiple bonding. Compounds 1 and 7 form interesting polymeric structures in the solid state with the aid of N-H...O=P hydrogen bonding interactions while the presence of the very bulky Dipp substituent on nitrogen in 2 prevents the participation of the N-H protons in hydrogen bonding with phosphoryl oxygen atoms.
- Murugavel, Ramaswamy,Pothiraja, Ramasamy
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p. 968 - 974
(2007/10/03)
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- 3-carbalkoxyamino-5-aminoacyl-5H-dibenz[b,f]azepines, and methods for making
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New 3-carbalkoxyamino-5-aminoacyl-5H-dibenz[b,f]azepines and their pharmaceutically acceptable acid addition salts, and methods for their synthesis are described. These compounds are useful as antiarrhythmic agents in the treatment of heart disorders. The new compounds are made by reacting a 3-carbalkoxyamino-5-halogenacyl-5H-dibenz[b,f]azepines with an amine to form the desired target product, which can be optionally converted into its pharmaceutically acceptable acid addition salt.
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- Hydrogenolysis of 1-Aminopyrazoles: Synthesis of Primary and Secondary Alkylamines
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The tautomerizable N-aminopyrazolone 9, the O-methyl 1 and N-methyl derivatives 4 were condensed with carbonyl compounds to give the alkenylaminopyrazoles 12, 2a-g and 5c, wich, under mild conditions, were hydrogenated to the corresponding alkylamino derivatives.The subesquent hydrogenation of the latter ones gave different results according to the structure of the starting material.The 5-methoxy-1-alkylaminopyrazoles 3a-g yielded the 5-methoxypyrazole 15 and the corresponding primary amines in good yields.On the contrary, N-methyl-1-alkylaminopyrazolone-5 6c gave 1-a lkylpyrazolone-3 8.
- Adembri, G.,Camparini, A.,Ponticelli, F.,Scotton, M.
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p. 321 - 326
(2007/10/02)
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- Optimized procedures for one-pot conversion of alkyl bromides into amines via the Staudinger reaction
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New optimized procedures for transforming primary and secondary alkyl bromides into the corresponding primary amine salts have been elaborated. Essential modifications of azidation and deprotection of intermediate triethoxyphosphine alkylimides resulted in substantial improvement of the overall yields. Conversion of ammonium tosylates and hydrochlorides into free amines in a nonaqueous medium is described.
- Koziara,Zwierzak
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p. 1063 - 1065
(2007/10/02)
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- Retro Aza Diels-Alder Reactions of 2-Azanorbornenes: Improved Methods for the Unmasking of Primary Amines
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The unmasking of primary amines via the heterocycloreversion of N-alkyl-2-azanorbornenes can be catalyzed by either copper(II) or a sulfonic acid based ion exchange resin which obviates the necessity of employing a reactive dienophile to trap the cyclopentadiene as it is produced.
- Grieco, Paul A.,Clark, Jerry D.
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p. 2271 - 2272
(2007/10/02)
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- Incorporation and Deoxygenation of Carbon Dioxide: A Metal-Assisted Facile Conversion of Carbon Dioxide and Primary Amines to Isocyanates
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Metal N-alkylcarbamato complexes (M = Na, n = 1; M = Mn, Co, n =2) were prepared by treating CO2 with a primary amine RNH2 (R = Ph, Cy, Pr) and various complex precursors.For M = Mn or Co and R = Cy, MCl2 can be used as starting material.These complexes were readily decomposed by acyl halides R'COCl (R' = Ph, Me), and two reaction pathways were observed.One led to decarboxylation and formation of amides RNHC(O)R', while the other afforded isocyanate RNCO and carboxylic acid (M = Na) or carboxylic anhydride (M = Mn, Co).Analysis of the reaction products showed that the metal plays a major role in the formation of the isocyanate, intercepting one of the reaction products.A mechanistic rationalization is proposed.
- Belforte, Antonio,Dell'Amico, Daniela Belli,Calderazzo, Fausto
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p. 1891 - 1898
(2007/10/02)
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- Reduction d'azides par la triphenylphosphine en presence d'eau : une methode generale et chimioselective d'acces aux amines primaires
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The reaction of azides with one equivalent of triphenylphosphine in the presence of a slight excess of water in THF leads quantitatively to the corresponding primary amines.This transformation is chemoselective.
- Knouzi, Noureddine,Vaultier, Michel,Carrie, Robert
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p. 815 - 819
(2007/10/02)
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- Conversion of Aliphatic Amides into Amines with benzene. Scope of the Reaction
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The reagent benzene, PIFA, brings about the facile oxidative rearrangement of aliphatic amides to amines in mildly acidic (pH 1-3) mixed aqueous-organic solvents.Aromatic amines are further oxidized by the reagent and therefore cannot be prepared by this method.The rearrangement, which is in effect an "Hofmann rearrangement", occurs with complete retention of configuration in the migrating group, and the rate of the reaction follows approximately the migratory aptitudes of the migrating groups determined for other similar reactions.Isocyanates are intermediates in the rearrangement but are rapidly hydrolyzed to the product amines under the mildly acidic conditions.The acidic conditions protect the product amines from reacting with the isocyanate intermediates and forming ureas.The reaction is accelerated by addition of pyridine to a pH of approximately 3.The scope of the reaction is discussed.
- Loudon, G. Marc,Radhakrishna, A. S.,Almond, Merrick R.,Blodgett, James K.,Boutin, Raymond H.
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p. 4272 - 4276
(2007/10/02)
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- Asymmetric Reductive Amination of Cycloalkanones, 2. Synthesis and Absolute Configuration of 2-Substituted Cyclohexanamines
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Asymmetric synthesis of 2-substituted cyclohexanamines from racemic cyclohexanones by means of reductive amination in a three-step procedure is described.Condensation of the ketones 5 with the optically active auxiliary amines 6 leads to the imines 7, which are hydrogenated to the secondary amines 8 with Raney nickel.Hydrogenolysis with palladium-on-charcoal yields the primary amines 9.With Raney nickel as catalyst the synthesis of the amines 8 and 9 runs with high chemical yield under complete diastereomeric and high grade enantiomeric control, respectively.Enantiomeric excess is determined via the diastereomeric acylamines 10 by means of HPLC.Stereochemical analysis including the absolute configuration of 8 and 9 is performed with 1H, 13C NMR spectroscopy, via the CD of the salicylidenes 11 and the X-ray spectrum of the amine 9c. - Reaction mechanism is investigated via the partially deuterated amine 13 to come up as a kinetically controlled asymmetric hydrogenation combined with a thermodynamically controlled transformation.
- Knupp, Gerd,Frahm, August W.
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p. 2076 - 2098
(2007/10/02)
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- THE APPLICATION OF DIALKYLPHOSPHITE AS THE AMINO PROTECTION REAGENT IN ORGANIC SYNTHESIS
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The acid hydrolysis of N-phenyl-N-dialkyl-phosphoramidates was studied by HPLC, the N-phenyl-N-diisopropylphosphoramidate has half life 53 min in 6N HCl at 50 deg C.The P-N bonds of these phosphoryl derivatives also show a relative stability in organic and Lewis acids.
- Zhao, Yu-Fen,Ji, Gai-Jiao,Xi, She-Kang,Tang, Hue-Gong,Song, Ai-Teng,Wei, Shou-Zuo
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p. 155 - 158
(2007/10/02)
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- N,N'-BIS(1-CHLOROALKYL)CARBODIIMIDES. II. REACTIONS WITH PROTON-CONTAINING NUCLEOPHILIC REAGENTS
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The reactions of N,N'-bis(1-chloroalkyl)carbodiimides with proton-containing nucleophilic reagents were investigated.It was shown that substitution products retaining the carbodiimide structure are formed in the reactions with alcohols and phenols.The action of water or primary amines is accompanied by fragmentation of the molecule and leads to the production of chloroformamidine or N-substituted guanidines.Secondary amines act on N,N'-bis(1-chloroalkyl)carbodiimides to form diazadienes, which exist as mixtures of Z,E isomers.
- Fetyukhin, V. N.,Vovk, M. V.,Pirozhenko, V. V.,Samarai, L. I.
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p. 1822 - 1828
(2007/10/02)
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- The Synthesis of Alkyl- and Aryl-Substituted 1,3,5-Triazines
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The reaction of chloromethyleneiminium salts with N-cyanoamidines provides a new and versatile route to alkyl- and aryl-substituted 1,3,5-triazines.Variation of substituents in the starting materials allows the synthesis of monoaryl-, diaryl-, alkyl-aryl- and certain mono- and di-alkyl-1,3,5-triazines bearing a variety of other substituents including hydrogen, chlorine and O-, S- and N-radicals.The generally good yields, ready availability of starting materials, and the scope and facility of the reaction make it the method of choice for the synthesis of 1,3,5-triazines with these substitution patterns.
- Harris, Roger L. N.
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p. 623 - 634
(2007/10/02)
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- Carboxyl terminated polydienes
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Carboxyl terminated polymers prepared by reacting a cyclic anhydride with a liquid polymeric hydroxyl terminated polymer selected from polyethers, polydienes, and copolymers of the dienes with styrene or acrylonitrile in the presence of a catalyst selected from quaternary ammonium salts and from halogen acid salts of amines. The carboxyl terminated polymers can be used as flexibilizers in epoxy resins.
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