- Simple RuCl3-catalyzed N-Methylation of Amines and Transfer Hydrogenation of Nitroarenes using Methanol
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Methanol is a potential hydrogen source and C1 synthon, which finds interesting applications in both chemical synthesis and energy technologies. The effective utilization of this simple alcohol in organic synthesis is of central importance and attracts scientific interest. Herein, we report a clean and cost-competitive method with the use of methanol as both C1 synthon and H2 source for selective N-methylation of amines by employing relatively cheap RuCl3.xH2O as a ligand-free catalyst. This readily available catalyst tolerates various amines comprising electron-deficient and electron-donating groups and allows them to transform into corresponding N-methylated products in moderate to excellent yields. In addition, few marketed pharmaceutical agents (e. g., venlafaxine and imipramine) were also successfully synthesized via late-stage functionalization from readily available feedstock chemicals, highlighting synthetic value of this advanced N-methylation reaction. Using this platform, we also attempted tandem reactions with selected nitroarenes to convert them into corresponding N-methylated amines using MeOH under H2-free conditions including transfer hydrogenation of nitroarenes-to-anilines and prepared drug molecules (e. g., benzocaine and butamben) as well as key pharmaceutical intermediates. We further enable one-shot selective and green syntheses of 1-methylbenzimidazole using ortho-phenylenediamine (OPDA) and methanol as coupling partners.
- Sarki, Naina,Goyal, Vishakha,Tyagi, Nitin Kumar,Puttaswamy,Narani, Anand,Ray, Anjan,Natte, Kishore
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p. 1722 - 1729
(2021/04/19)
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- Synthesis process of dialkyl dimethyl ammonium chloride
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The invention discloses a synthesis process of dialkyl dimethyl ammonium halide, which comprises the following steps: mixing primary alkyl halide R1X and long-chain alkyl dimethylamine R2(CH3)2N, heating to 130-150 DEG C in a closed container, keeping the temperature to react for 4-6 hours, cooling, and diluting with an ethanol water solution to obtain dialkyl dimethyl ammonium halide, wherein thereaction temperature is determined by the number of carbon atoms of R1 and R2, and the formula is 130 DEG C+2.5(CR1+CR216)DEG C. Primary alkyl halide and long-chain alkyl dimethylamine directly reactto generate dialkyl dimethyl ammonium halide, so that the use of flammable and combustible gaseous raw materials is avoided, and the production safety is improved, the production process flow and equipment are simple, the production cost is low, industrial popularization is facilitated, no acid or salt byproduct is generated, and the product is high in purity, free of three wastes and environmentally friendly.
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Paragraph 0022
(2021/03/11)
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- Commercial Pd/C-Catalyzed N-Methylation of Nitroarenes and Amines Using Methanol as Both C1 and H2 Source
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Herein, we report commercially available carbon-supported-palladium (Pd/C)-catalyzed N-methylation of nitroarenes and amines using MeOH as both a C1 and a H2 source. This transformation proceeds with high atom-economy and in an environmentally friendly way via borrowing hydrogen mechanism. A total of >30 structurally diverse N-methylamines, including bioactive compounds, were selectively synthesized with isolated yields of up to 95%. Furthermore, selective N-methylation and deuteration of nimesulide, a nonsteroidal anti-inflammatory drug, were realized through the late-stage functionalization.
- Goyal, Vishakha,Gahtori, Jyoti,Narani, Anand,Gupta, Piyush,Bordoloi, Ankur,Natte, Kishore
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p. 15389 - 15398
(2019/12/04)
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- Molecular Catalysts for Selective Hydrogenolysis of Amides
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A compound by the name 1,1,1-tris(di(3,5-dimethoxyphenyl)phosphino-methyl)ethane. The compound can be represented by the structure of formula (I): The compound is useful as a ligand for ruthenium to form an organometallic complex. The complex is an active catalyst for the hydrogenolysis of amides to form amines and optionally alcohols.
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Paragraph 0081-0082
(2019/11/22)
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- TERTIARY AMINE PREPARATION PROCESS
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The present invention relates to a process for producing a tertiary amine, including the following steps (1) and (2): Step (1); introducing an alcohol having 1 to 36 carbon atoms and a raw amine represented by the following general formula (I) into a first reaction vessel to react with each other in the presence of a catalyst and hydrogen, and then continuing the reaction while discharging water produced in the reaction and a hydrogen-containing gas out of a reaction system in the first reaction vessel: R1R2NH??(I) wherein R1 and R2 are each independently a hydrogen atom or a hydrocarbon group having 1 to 36 carbon atoms; and Step (2): introducing the hydrogen-containing gas discharged from the first reaction vessel into a second reaction vessel to reduce an amount of carbon monoxide contained in the hydrogen-containing gas, and then introducing a part or whole of the hydrogen-containing gas into the first reaction vessel.
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Paragraph 0104-0106; 0119-0121
(2013/11/06)
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- METHOD FOR PRODUCING TERTIARY AMINE
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The present invention provides a method for producing a tertiary amine by using a secondary amine and an alcohol as starting materials to obtain a corresponding tertiary amine. The method of the present invention includes reacting a secondary amine with an alcohol in the presence of a catalyst, wherein the catalyst is previously used in the reaction of a primary amine with an alcohol to obtain a tertiary amine.
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Page/Page column 4
(2012/11/08)
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- METHOD FOR PRODUCING TERTIARY AMINE
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The present invention provides a method for producing a tertiary amine by reacting an alcohol with a primary or secondary amine in the presence of a film catalyst containing a thermosetting resin and an active metal, wherein the film catalyst is reduced at 100 to 150° C., and a method for activating the film catalyst containing a thermosetting resin and an active metal, including applying a coating agent containing the thermosetting resin and a powder catalyst onto the surface of a support, drying the resultant, curing it at 80 to 170° C., and reducing the catalyst at 100 to 150° C.
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Page/Page column 6
(2010/09/05)
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- The ruthenium-catalyzed reduction and reductive N-alkylation of secondary amides with hydrosilanes: Practical synthesis of secondary and tertiary amines by judicious choice of hydrosilanes
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(Chemical Equation Presented) A triruthenium cluster, (μ3, η2,η3,η5-acenaphthylene)Ru 3(CO)7 (1) catalyzes the reaction of secondary amides with hydrosilanes, yielding a mixture of secondary amines, tertiary amines, and silyl enamines. Production of secondary amines with complete selectivity is achieved by the use of higher concentration of the catalyst (3 mol %) and the use of bifunctional hydrosilanes such as 1,1,3,3-tetramethyldisiloxane. Acidic workup of the reaction mixture affords the corresponding ammonium salts, which can be treated with a base, providing a facile method for isolation of secondary amines with high purity. In contrast, tertiary amines are formed with high selectivity by using lower concentration of the catalyst (1 mol %) and polymeric hydrosiloxanes (PMHS) as reducing agent. Reduction with PMHS encapsulates the ruthenium catalyst and organic byproducts to the insoluble silicone resin. The two reaction manifolds are applicable to various secondary amides and are practical in that the procedures provide the desired secondary or tertiary amine as a single product. The product contaminated with only minimal amounts of ruthenium and silicon residues. On the basis of the products and observed side products as well as NMR studies a mechanistic scenario for the reaction is also described.
- Hanada, Shiori,Ishida, Toshiki,Motoyama, Yukihiro,Nagashima, Hideo
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p. 7551 - 7559
(2008/02/12)
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- Process for obtaining amines by reduction of amides
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N-substituted, and N,N- disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 7
(2008/06/13)
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- Process for obtaining amines by reduction of amides
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N-substituted, and N,N-disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 4
(2008/06/13)
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- PROCESS FOR OBTAINING AMINES BY REDUCTION OF AMIDES
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Disclosed is a process for the preparation of primary, secondary and tertiary amines via a catalytic hydrogenation of unsubstituted, N- substituted, and N,N- disubstituted amides. The amide is led, together with an auxiliary amine, in vaporised form in a hydrogen containing gas flow over the catalyst. The process can be carried out at relatively low pressures, between 2 and 50 bars, using typical hydrogenation catalysts like CuCr-type catalysts. The amine is obtained with high yield and high selectivity. The process can be carried out in a continuous fixed bed reactor.
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Page/Page column 11-12
(2008/06/13)
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- PROCESS FOR PRODUCTION OF TERTIARY AMINES
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A process for producing a tertiary amine from an alcohol and a primary or secondary amine by use of a film type catalyst, which comprises circulating the reaction fluid through a reaction tank equipped with an external circulation line packed with the film type catalyst at a rate of at least three times/h to conduct the reaction.
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Page/Page column 16-18
(2008/06/13)
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- Amines from alcohols
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Mono- and di-lower alkylamines, e.g. methylamine or dimethylamine, are alkylated by reaction with C8-22 alcohol in the presence of hydrogen at a temperature of about 150°-275° C. in contact with a copper-zinc-alkaline earth metal base containing catalyst (e.g., CuO-ZnO-Ba(OH)2) while removing water formed in the reaction.
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- Amine oxide process and composition
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A highly concentrated aqueous solution of a di-C6-20 alkyl methylamine oxide containing at least 50 weight percent of the amine oxide can be made without gel formation by reacting at least 40 weight percent aqueous hydrogen peroxide with a di-C6-20 alkyl methyl or ethylamine. These concentrated solutions offer large freight savings in shipping the amine oxides to remote locations.
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