- Influence of the distance between ionizable groups on the protonation behavior of various hexaamines
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A synthesis route for N,N,N',N'-tetraaminoethyl-1,2-ethylenediamine, N,N,N',N'-tetraaminopropyl-1,2-ethylenediamine, N,N,N',N'-tetraaminopropyl- 1,3-propylenediamine and N,N,N',N'-tetraaminopropyl-1,4-butylenediamine is presented. These molecules differ from each other in the number of carbon atoms between the six amino groups. This results in different protonation behavior. Potentiometric titrations are performed in 0.1 M and 1.0 M KCl, and the six macroscopic protonation constants are obtained from these curves. An Ising model with a limited number of microscopic protonation constants and short-ranged pair interactions describes the protonation behavior quantitatively. The results are compared to those of other, similar molecules. The advantage of the Ising model over empirical relations such as the Taft equations is the more systematic approach with which the titration curves of more complex molecules can be described. The values for the Ising model parameters obtained here can be used to predict the protonation behavior of more complex, in particular larger, polyamines.
- Van Duijvenbode, Rene C.,Rajanayagam, Anton,Koper, Ger J.M.,Borkovec, Michal,Paulus, Wolfgang,Steuerle, Ulrich,Haeussling, Lukas
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Read Online
- A cobalt phosphide catalyst for the hydrogenation of nitriles
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The study of metal phosphide catalysts for organic synthesis is rare. We present, for the first time, a well-defined nano-cobalt phosphide (nano-Co2P) that can serve as a new class of catalysts for the hydrogenation of nitriles to primary amines. While earth-abundant metal catalysts for nitrile hydrogenation generally suffer from air-instability (pyrophoricity), low activity and the need for harsh reaction conditions, nano-Co2P shows both air-stability and remarkably high activity for the hydrogenation of valeronitrile with an excellent turnover number exceeding 58000, which is over 20- to 500-fold greater than that of those previously reported. Moreover, nano-Co2P efficiently promotes the hydrogenation of a wide range of nitriles, which include di- and tetra-nitriles, to the corresponding primary amines even under just 1 bar of H2 pressure, far milder than the conventional reaction conditions. Detailed spectroscopic studies reveal that the high performance of nano-Co2P is attributed to its air-stable metallic nature and the increase of the d-electron density of Co near the Fermi level by the phosphidation of Co, which thus leads to the accelerated activation of both nitrile and H2. Such a phosphidation provides a promising method for the design of an advanced catalyst with high activity and stability in highly efficient and environmentally benign hydrogenations. This journal is
- Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo,Nakata, Ayako,Sheng, Min,Yamasaki, Jun
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p. 6682 - 6689
(2020/08/24)
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- pyrrole Shalom intermediates
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The invention particularly relates to an amine phosphate binder bixalomer intermediate and a preparation method thereof. The preparation method comprises the following steps: reacting a raw material 3,3'-diamidodipropyl amine under the action of benzyl chloroformate to obtain 3,3'-dibenzyloxyamidodipropyl amine, carrying out substitution reaction on the 3,3'-dibenzyloxyamidodipropyl amine and 1,4-dibromobutane or 1,4-dichlorobutane to obtain N,N,N',N'-tetra(3-dibenzyloxyamido)-1,4-butanediamine, and carrying out deprotection by pressure hydrogenation under the action of Pd-C to obtain N,N,N',N'-tetra(3-aminopropyl)-1,4-butanediamine. The method has the advantages of cheap and accessible raw materials, operable reaction, high yield and fewer three wastes, and thus, has excellent industrial prospects.
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Paragraph 0059; 0060; 0061; 0062; 0063; 0064-0072
(2017/07/23)
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- A preparation method of the midbody pyrrole Shalom
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The invention discloses a bixalomer intermediate preparing method. Allyl bromide is used as a raw material, 3-nitrine-1-propylene is obtained under the effect of sodium azide, the 3-nitrine-1-propylene and 1,4-butanediamine performs addition reaction to obtain N,N,N,N-quadri(3-azide propyl)-1,4-butanediamine, and then hydrogenation reaction is performed to obtain N,N,N,N-quadri(3-amino propyl)-1,4-butanediamine. The raw materials adopted by the method are cheap and easy to obtain, a one-pot method is adopted to perform reaction, operation is simple and convenient, the yield is high, the purity of a product is higher, the purity, detected by HPLC, of quadri-amino propyl-1,4-butanediamine is above 99%, waste gas, waste water and industrial residues produced by the adopted preparation process are little, and therefore, the bixalomer intermediate preparing method has very good industrial prospect.
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Paragraph 0058; 0059
(2017/07/12)
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- Nano polypropylenimine dendrimer (DAB-PPI-G1): As a novel nano basic-polymer catalyst for one-pot synthesis of 2-amino-2-chromene derivatives
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The nano polypropylenimine dendrimer (DAB-PPI-G1) Lewis base catalyst was found to be a highly efficient and recoverable catalyst for the rapid and convenient synthesis of 2-amino-2-chromene derivatives through the three-component condensation of aromatic aldehydes, malononitrile or ethyl cyanoacetate and phenols under solvent-free conditions in excellent yields and short reaction times.
- Maleki, Behrooz,Sheikh, Safoora
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p. 42997 - 43005
(2015/05/27)
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- Phosphine-free tetradentate salicylaldimine ligand complexed with palladium: First application in heck reactions
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Heck reactions were carried out using phosphine-free tetradentate salicylaldimine ligand complexed with PdCl2 under mild reaction conditions, short reaction time, and low palladium loading. All aryl iodides underwent coupling reactions with olefins, giving corresponding trans-products, with good to excellent yields, whereas aryl bromides gave very poor yields and aryl chlorides failed to react.
- Kalhapure, Rahul S.,Govender, Thirumala,Akamanchi, Krishnacharya G.
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p. 3337 - 3345
(2015/10/06)
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- AMINE POLYMERS FOR USE AS BILE ACID SEQUESTRANTS
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The present invention provides crosslinked amine polymers effective for binding and removing bile salts from the gastrointestinal tract. These bile acid binding polymers or pharmaceutical compositions thereof can be administered to subjects to treat various conditions, including hypercholesteremia, diabetes, pruritus, irritable bowel syndrome-diarrhea (IBS-D), bile acid malabsorption, and the like.
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Paragraph 0162
(2014/12/09)
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- Process for the preparation of N,N,N',N'-tetrakis(3-aminopropyl)-1,4-butanediamine
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The invention provides a process for the preparation of N,N,N',N'-tetrakis(3-aminopropyl)-1,4-butanediamine by hydrogenation of 3,3',3",3"'-(1,4-butanediyldinitrilo)tetrakispropanenitrile, wherein 3,3',3",3"'-(1,4-butanediyldinitrilo)tetrakispropanenitrile is continuously added to a suspension or solution of a catalyst in a solvent which optionally comprises one or more additives and is stirred at a temperature in the range from 40 to 150 °C under a hydrogen pressure, characterized in that (i) the solvent is tetrahydrofuran, (ii) the catalyst is a hydrogenation catalyst selected from the group consisting of (1) Sponge Metal Cobalt, A-8B46, promoted with Nickel and Chromium, (2) Raney Cobalt, 2724, promoted with Chromium, (3) Actimet Cobalt and (4) Activated Ni catalyst, B 113 W, and (iii) the hydrogen pressure is from 30 to 50 bar. This special combination of catalyst and solvent allows the preparation of N,N,N',N'-tetrakis(3-aminopropyl)-1,4-butanediamine in high purity under a moderate hydrogen pressure which is suitable for large scale synthesis.
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Paragraph 0022-0026
(2013/03/26)
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- PROCESS FOR THE PREPARATION OF AMINOALKYLAMINES
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A process for the preparation of polyfunctional amines of the formulae by hydrogenation of the associated nitriles of the formulae with hydrogen, where A is an aromatic or aliphatic compound from the group of unsubstituted or substituted phenylene or naphthylene, methylene, unsubstituted or substituted ethylene, propylene, unsubstituted or substituted straight-chain or branched butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene andB is a straight-chain or branched aliphatic carbon chain having 1 to 10 carbon atoms, such as methylene, unsubstituted or substituted ethylene, propylene, unsubstituted or substituted straight-chain or branched butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, where at least one CH2 unit must be in direct vicinity to the amino group, andX can be missing or is a straight-chain or branched aliphatic carbon chain having 1 to 10 carbon atoms, such as methylene, unsubstituted or substituted ethylene, propylene, unsubstituted or substituted straight-chain or branched butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, characterized in that a melt, solution or suspension of the nitrile of the formula (I) or (II) is added over the course of the reaction time to a suspension or solution of a catalyst in a solvent which comprises ammonia and optionally other additives and is stirred at a temperature in the range from 60 to 150° C. under hydrogen pressure, is described.
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Page/Page column 2-3
(2010/06/19)
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