- Addition of secondary amines to α,β-unsaturated carbonyl compounds and nitrites by using microstructured reactors
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Several additions of amines to α,β-unsaturated carbonyl compounds (Michael additions) were performed in a continuous-flow microstructured reactor rig and compared to the respective batch reaction. Dimethylamine/diethylamine/piperidine and acrylic acid ethyl ester/acrylonitrile were employed as two sets of reactants, giving six reactions. Some of these reactions are highly exothermal. Using the traditional batch procedure the olefin must be added quite slowly to the diluted amine to ensure temperature control and safe operation; especially this is necessary for the addition of dimethylamine (40 mass % aqueous solution) to acrylonitrile. Good yields (>85%) are achieved in this way; however, processing time is very long (17-25 h). To reveal the intrinsic kinetic potential and thus to accelerate these reactions, the reactants were mixed in a continuous-flow microstructured reactor rig which allows rapid mixing and efficient removal of the reaction heat. In this way, reaction time was decreased to a few seconds up to about half an hour, which is a change by 2 orders of magnitude. While the yields achieved with the continuous-flow microstructured reactor rig matched those for the batch procedure, the space-time yields for the microflow processing are much higher, in the best case by a factor of about 650.
- Loewe,Hessel,Lob,Hubbard
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Read Online
- Cesium fluoride catalyzed Aza-Michael addition reaction in aqueous media
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A green approach to the Aza-Michael addition reaction between an amine and α,β-unsaturated compounds has been achieved by conventional as well as non-conventional methods. The reaction is catalyzed by cesium fluoride (CsF) in aqueous media at ambient temperature to afford the product in excellent yield. Ultrasound irradiation has been used as a non-conventional energy source, which reduces the reaction time with improved product yield.
- Labade, Vilas B.,Pawar, Shivaji S.,Shingare, Murlidhar S.
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- N-donor ligand as catalyst: A simple Aza-Michael addition reaction in aqueous media
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(Chemical Equation Presented) A novel approach for the Aza-Michael addition reactions between various amines and α,β-unsaturated esters, nitriles and ketones using N-donor Ligand catalyst (3 mol %) is described. The reactions are carried out in aqueous media at an ambient temperature to afford the products in excellent yields.
- Pawar, Shivaji S.,Dekhane, Deepak V.,Shingare, Murlidhar S.,Thore, Shivaji N.
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Read Online
- Insights into Thiourea-Based Bifunctional Catalysts for Efficient Conversion of CO2to Cyclic Carbonates
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The bifunctional thiourea catalyst system with both electrophilic and nucleophilic centers has been certified to be effective for fixing CO2 under mild reaction conditions; however, many questions remain, especially concerning the relationship between str
- Li, Zhuo-Qun,Zhang, Yao-Yao,Zheng, Yu-Jia,Li, Bo,Wu, Guang-Peng
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p. 3145 - 3155
(2022/02/14)
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- PREPARATION OF DIAMINE VIA THE PREPARATION OF AMINONITRILE
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A continuous method (P) for preparing diamine is described. The method includes reacting the corresponding alkene nitrile with the corresponding monoamine in order to form the corresponding aminonitrile. The monoamine can be introduced in molecular excess with respect to the alkene nitrile, wherein the unreacted monoamine is recirculated to the reaction; followed by reducing the aminonitrile produced by hydrogen in the presence of at least one alkali-metal hydroxide, water, and a hydrogenation catalyst; and purifying the diamine.
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Paragraph 0126; 0127
(2014/02/15)
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- Practical preparation of trimethoprim: A classical antibacterial agent
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An efficient, simple, and mild preparation of the classical antibacterial agent trimethoprim (1) was achieved in 85% overall yield from 3,4,5-trimethoxybenzaldehyde (2). First, the addition of propenenitrile (3) with dimethylamine almost quantitatively afforded 3-dimethylaminopropanenitrile (7). Then, by condensation of 7 with 2 as well as the continuous replacement of 3-dimethylamino group with aniline in situ, the key intermediate 3-anilino-2-(3,4,5-trimethoxybenzyl)propenenitrile (9) was obtained in an excellent yield of 91% with a one-pot procedure. Finally, the cyclization of 9 with guanidine nitrate furnished 1 in yields as good as 95% in the presence of the excessive sodium methoxide. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications1 to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Ji, Ya-Fei,Jiang, Jian-An,Liu, Hong-Wei,Liao, Dao-Hua,Wei, Xian-Yong
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supporting information
p. 1517 - 1522
(2013/05/22)
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- A novel photodegradable hyperbranched polymeric photoresist
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We report the first synthesis of a photodegradable hyperbranched polyacetal, wherein every repeat unit carries a photo-labile 2-nitrobenzyloxy moiety. The pristine HBP serves as a positive photoresist to create micron-size patterns; furthermore, by changing the terminal groups to dipropargyl acetal, clickable photo-patterned substrates can be generated.
- Chatterjee, Saptarshi,Ramakrishnan
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supporting information
p. 11041 - 11043
(2013/11/19)
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- PROCESS FOR THE PREPARATION OF AMINONITRILE AND DIAMINE, AND CORRESPONDING DEVICES
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The present invention relates to a continuous process for the preparation of an aminonitrile comprising the stages of: a) formation of the aminonitrile by reaction between an alkenyl nitrile, mixed with aminonitrile, and a monoamine introduced in molar excess with respect to the alkenyl nitrile; b) separation of the unreacted monoamine and the aminonitrile; c) reaction between the monoamine separated during stage b) and all or part of the alkenyl nitriie in order to form a mixture of aminonitrile and of unreacted alkenyl nitrile, with the alkenyl nitrile being introduced in molar excess with respect to the said monoamine; d) transfer of the mixture of aminonitrile and alkenyl nitrile resulting from stage c) to the reaction of stage a), e) in the case where only a portion of the alkenyl nitrile is introduced during stage c), introduction of the remaining molar amount of alkenyl nitrile into the mixture of stage d); the total molar amount of alkenyl nitrile introduced during stages c) and e) being equal to the molar amount of monoamine introduced during stage a). The present invention also relates to a process for the preparation of diamine comprising the continuous preparation of aminonitrile. The invention also relates to the devices corresponding to these processes.
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Page/Page column 6
(2013/03/26)
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- Sulfur and nitrogen mustard carbonate analogues
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Sulfur and nitrogen half-mustard compounds lose their aggressive properties when the chlorine atom is replaced by a carbonate moiety. The anchimeric effect of the novel mustard carbonate analogues is investigated. The reaction follows first-order kinetics, does not need any base, and occurs with -OH, -NH and acidic -CH nucleophiles. Most of these molecules are unexplored and might provide a novel strategy for the preparation of compounds previously not easily accessible. Copyright
- Arico, Fabio,Chiurato, Matteo,Peltier, Josephine,Tundo, Pietro
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experimental part
p. 3223 - 3228
(2012/07/31)
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- DMAPN Having a Low DGN Content and a Process for Preparing DMAPA from DMAPN Having a Low DGN Content
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The present invention relates to a process for preparing 3-dimethylaminopropylamine (DMAPA) by reacting 3-dimethylaminopropionitrile (DMAPN) with hydrogen in the presence of a catalyst, wherein the DMAPN used has a content of 2-(dimethylaminomethyl)glutaronitrile (DGN) of 300 ppm by weight or less, based on the DMAPN used. Furthermore, the present invention relates to mixtures of DMAPN and DGN, wherein the weight ratio of DMAPN to DGN is in the range from 1 000 000:5 to 1 000 000:250.
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Page/Page column 5-6
(2012/02/06)
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- PROCESS FOR PREPARING AMINOALKYLNITRILES AND DIAMINES FROM SUCH NITRILES
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The present invention relates to a process for preparing an aminoalkyl nitrile by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, which comprises the steps (a) introduction of the corresponding monoamine into a continuously conveyed reaction stream;(b) introduction of the corresponding alkenyl nitrite into the reaction stream, with this already comprising the aminoalkyl nitrile on addition;(c) reaction of the reaction stream in a first reaction region; and(d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction. The invention further relates to a process for preparing a diamine from the aminoalkyl nitrile, suitable apparatuses for carrying out the processes and their corresponding use.
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Page/Page column 5-6
(2009/04/24)
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- Process for the Synthesis of Dmapa
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The present invention relates to a process for the industrial preparation of a diamine starting from a corresponding alkenyl nitrile comprising at least one C-C double bond, which comprises the steps (a) reaction of the alkenyl nitrile with a corresponding monoamine in a first reactor so that the monoamine adds exothermically onto the at least one double bond to form an aminoalkyl nitrile, with the monoamine and water being charged initially and the alkenyl nitrile being fed in;(b) evaporation of unreacted alkenyl nitrile and monoamine to increase the concentration of the aminoalkyl nitrile product in the bottoms of the first reactor;(c) transfer of the aminoalkyl nitrile bottom product from step (b) to a second reactor;(d) batchwise catalytic hydrogenation of the aminoalkyl nitrile transferred in step (c) to the diamine in the second reactor, with each batch being obtained by initially charging a catalyst suitable for the hydrogenation of nitriles to amines and also water, the desired diamine and a base, introducing hydrogen into the second reactor and feeding in the aminoalkyl nitrile transferred in step (c); and(e) isolation of the diamine and, if appropriate, repetition of the steps (a) to (e). The invention further relates to an apparatus for preparing these diamines and the use of the apparatuses. A preferred diamine is 3-dimethylaminopropylamine (DMAPA).
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Page/Page column 3-4
(2009/01/20)
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- Thermodynamics of the donor-acceptor interaction of zinc(II)tetraphenylporphyrin with mono- and dinitriles
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Calorimetric titration was used for the first time to measure the thermodynamic characteristics of complexation of zinc(II) tetraphenylporphyrin with mono- and dinitriles. The effect of the electronic structure and the electron density distribution in the molecular ligands on the thermodynamic characteristics was examined. In passing from the benzene to the carbon tetrachloride solvent, both the exothermicity of the reactions under study and the stability of the complexes formed increase.
- Lebedeva,Mikhailovskii,V'yugin,Davydova
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p. 1028 - 1030
(2007/10/03)
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- 5-HT3 receptor agonist, novel thiazole derivative and intermediate thereof
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A 5-HT3 receptor against containing a thiazole derivative as the effective ingredient is provided and is represented by the Formula (I): STR1 wherein the A ring is substituted or unsubstituted and represents a benzene or a heterocyclic ring with one or two heteroatoms; one of L1 or L2 represents a single bond and the other is non-existent or represents an alkylene or alkenylene group; R represents: STR2
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- Indium trichloride-catalyzed conjugate addition of amines to α,β-ethylenic compounds in water
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Catalytic amount of indium (III) trichloride efficiently catalyzed Michael reaction between amines and α,β-ethylenic compounds in water and under mild conditions. Indium trichloride can be recovered and reused without decrease in yield.
- Loh, Teck-Peng,Wei, Lin-Li
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p. 975 - 976
(2007/10/03)
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- Joint preparation of 3-dialkylaminopropionitriles, bis-(2-cyanoethyl) ether and, if desired, ethylene-cyanohydrin
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3-Dialkylaminopropionitriles STR1 where R1 and R2 are each C1 -C4 -alkyl which may furthermore be bonded to form a 5-membered or 6-membered ring, bis-(2-cyanoethyl) ether II and, if desired, ethylenecyanohydrin III are prepared jointly by a process in which (a) acrylonitrile and water are reacted in the presence of a base at from 60° to 150° C. to give a mixture of acrylonitrile, water and bis-(2-cyanoethyl) ether II, the base being a mineral base, a quaternary nitrogen base or a mixture of these, (b) this mixture is reacted at about 0°-50° C. with a dialkylamine of the general formula IV STR2 to give a mixture of water, a dialkylaminopropionitrile I and bis-(2-cyanoethyl) ether II, and this mixture is separated into its components and (c) if desired, the ether II obtained in proces stage (b) or an aqueous solution of this ether and/or the reacted mixtures containing this ether and obtained from process stage (a) or (b) is allowed to react at from 50° to 150° C. with the dialkylamine IV to give a mixture of a 3-dialkylaminopropionitrile I and ethylenecyanohydrin III, and, if desired, the said mixture is separated into its components.
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- THE S- AND N-ADDITION OF THE COMPLEXES OF AMINES WITH SULFUR DIOXIDE TO ELECTROPHILIC ALKENES
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The addition of the complexes of amines with sulfur dioxide to acrylonitrile, methacrylonitrile, and crotononitrile was relized.The reactions of acrylonitrile with CH3NH2 -> SO2 and C2H5NH2 -> SO2 complexes take place with the formation of N-alkyl-2-cyanoethanesulfonamides (S-addition of the complexes at the double bond).The electrophilic alkenes react with (CH3)2NH -> SO2 and (C2H5)2NH -> SO2 to form complexes of the substituted β-aminonitriles with sulfur dioxide (N-addition of the complexes at the double bond).
- Bodrikov, I. V.,Krasnov, V. L.,Samodurov, I. N.,Kazantsev, O. A.
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p. 923 - 928
(2007/10/02)
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- Group Transfer Reactions. - Tetracarbonylferrates from Orthoformic Acid Derivatives and Pentacarbonyliron
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The nucleophilic leaving group X is transferred from orthoformic acid derivatives HC(NR2)X (X= NR2, OR, CN) to Fe(CO)5.No such reactions were observed between 4 and amide acetals (HCX2NR2) or ortho ester derivatives HCX3 (X= OR, SR).The structures of the transition metal-acyl complexes obtained have been determined by IR and NMR spectra.In the case of the reaction of tris(dimethylamino)methane (3a) with 4 the equilibrium between the resulting amidinium-carbamoyltetracarbonylferrate complex 5a and the starting materials was investigated.The equilibrium is shifted completely in favor of the ionic compound 5a.However, 3a could be isolated by extraction of this solution with an apolar solvent.Alkylation of 5a with triethyloxonium tetrafluoroborate leads to the tetracarbonyliron-carbene complex 13.Reaction of 5a with acrylonitrile or methyl acrylate by addition of both the nucleophile "NR2-" and the electrophile + and subsequent eliminations gives the β-dimethylamino substitution product 18 and 21, respectively.In contrast 3a induces polymerisation of acrylonitrile.
- Daub, Joerg,Hasenhuendl, Adelheid,Krenkler, Karl P.,Schmetzer, Johannes
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p. 997 - 1015
(2007/10/02)
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