1738-25-6Relevant articles and documents
Addition of secondary amines to α,β-unsaturated carbonyl compounds and nitrites by using microstructured reactors
Loewe,Hessel,Lob,Hubbard
, p. 1144 - 1152 (2006)
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.
Decarboxylation reactions. III. Reaction of N,N' and N,O linked methylene compounds with carboxylic acids
Sekiya,Matsuda,Ito
, p. 1579 - 1585 (1975)
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Insights into Thiourea-Based Bifunctional Catalysts for Efficient Conversion of CO2to Cyclic Carbonates
Li, Zhuo-Qun,Zhang, Yao-Yao,Zheng, Yu-Jia,Li, Bo,Wu, Guang-Peng
, p. 3145 - 3155 (2022/02/14)
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
Practical preparation of trimethoprim: A classical antibacterial agent
Ji, Ya-Fei,Jiang, Jian-An,Liu, Hong-Wei,Liao, Dao-Hua,Wei, Xian-Yong
supporting information, p. 1517 - 1522 (2013/05/22)
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.
PROCESS FOR THE PREPARATION OF AMINONITRILE AND DIAMINE, AND CORRESPONDING DEVICES
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Page/Page column 6, (2013/03/26)
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.