34911-51-8Relevant articles and documents
Microwave-assisted Vilsmeier-Haack synthesis of Pyrazole-4-carbaldehydes
Kumari, Poonam,Sood, Sumit,Kumar, Anil,Singh, Karan
, p. 796 - 804 (2019/11/28)
The synthesis of 4-formylpyrazoles using Vilsmeier-Haack reagent is a common protocol in pyrazole chemistry. An efficient microwave-assisted synthesis of 4-formylpyrazoles by employing Vilsmeier-Haack reagent (OPC-VH) derived from phthaloyl dichloride/dimethylformamide has been described. This method offers the advantages of operational simplicity, avoiding the use of POCl3 as toxic reagents and reuse of the by-product in the preparation of phthaloyl dichloride.
A Method for the Catalytic Enantioselective Synthesis of Chiral α-Azido and α-Amino Ketones from Racemic α-Bromo Ketones, and Its Generalization to the Formation of Bonds to C, O, and S
Da Silva Gomes, Roberto,Corey
supporting information, p. 20058 - 20061 (2019/12/27)
A new and practical method has been developed for the transformation of racemic α-bromo ketones to chiral α-azido and α-amino ketones with high enantioselectivity using phase transfer, ion-pair mediated reactions with a recoverable chiral quaternary salt (10 mol %) as catalyst in fluorobenzene-water. The process has been generalized to a variety of other attachments including of C, O, S, and NHR.
Novel benzene-based carbamates for ache/bche inhibition: Synthesis and ligand/structure-oriented sar study
Bak, Andrzej,Kozik, Violetta,Kozakiewicz, Dariusz,Gajcy, Kamila,Strub, Daniel Jan,Swietlicka, Aleksandra,Stepankova, Sarka,Imramovsky, Ales,Polanski, Jaroslaw,Smolinski, Adam,Jampilek, Josef
, (2019/05/10)
A series of new benzene-based derivatives was designed, synthesized and comprehensively characterized. All of the tested compounds were evaluated for their in vitro ability to potentially inhibit the acetyl-and butyrylcholinesterase enzymes. The selectivity index of individual molecules to cholinesterases was also determined. Generally, the inhibitory potency was stronger against butyryl-compared to acetylcholinesterase; however, some of the compounds showed a promising inhibition of both enzymes. In fact, two compounds (23, benzyl ethyl(1-oxo-1-phenylpropan-2-yl)carbamate and 28, benzyl (1-(3-chlorophenyl)-1-oxopropan-2-yl) (methyl)carbamate) had a very high selectivity index, while the second one (28) reached the lowest inhibitory concentration IC50 value, which corresponds quite well with galanthamine. Moreover, comparative receptor-independent and receptor-dependent structure–activity studies were conducted to explain the observed variations in inhibiting the potential of the investigated carbamate series. The principal objective of the ligand-based study was to comparatively analyze the molecular surface to gain insight into the electronic and/or steric factors that govern the ability to inhibit enzyme activities. The spatial distribution of potentially important steric and electrostatic factors was determined using the probability-guided pharmacophore mapping procedure, which is based on the iterative variable elimination method. Additionally, planar and spatial maps of the host–target interactions were created for all of the active compounds and compared with the drug molecules using the docking methodology.
Synthesis of α,β-dibromo ketones by photolysis of α-bromo ketones with N-bromosuccinimide: Photoinduced β-bromination of α-bromo ketones
Moon, Da Yoon,An, Sejin,Park, Bong Ser
, (2019/10/28)
Irradiation of α-bromopropiophenones in the presence of NBS results in the formation of α,β-dibromopropiophenones, which can be viewed as β-bromination of α-bromopropiophenones. The reaction is believed to go through a series of reactions; photoinduced C–Br bond cleavage, elimination of HBr to give α,β-unsaturated ketone intermediates, and addition of Br2, which are formed by the reaction between HBr and NBS. From mechanistic studies of the reaction, we have also found a very convenient method for α-debromination of the α,β-dibromopropiophenones which is by simple irradiation of the dibromo ketones in acetone or 2-propanol without the use of any additives. Our results demonstrate that bromine can be added into or eliminated from the alpha, beta, or both positions to the carbonyl group by photochemical methods, which make synthetic options of bromine containing carbonyl compounds versatile.
Across-the-World Automated Optimization and Continuous-Flow Synthesis of Pharmaceutical Agents Operating Through a Cloud-Based Server
Fitzpatrick, Daniel E.,Maujean, Timothé,Evans, Amanda C.,Ley, Steven V.
supporting information, p. 15128 - 15132 (2018/10/31)
The power of the Cloud has been harnessed for pharmaceutical compound production with remote servers based in Tokyo, Japan being left to autonomously find optimal synthesis conditions for three active pharmaceutical ingredients (APIs) in laboratories in Cambridge, UK. A researcher located in Los Angeles, USA controlled the entire process via an internet connection. The constituent synthetic steps for Tramadol, Lidocaine, and Bupropion were thus optimized with minimal intervention from operators within hours, yielding conditions satisfying customizable evaluation functions for all examples.
Solvent free, light induced 1,2-bromine shift reaction of α-bromo ketones
An, Sejin,Moon, Da Yoon,Park, Bong Ser
, p. 6922 - 6928 (2018/10/24)
Photolysis of α-bromopropiophenones in acetonitrile results in formation of β-bromopropiophenones with good product selectivity, which can be coined as 1,2-Br shift reaction. The product selectivity increases when the reaction is done in neat or solid state, where only the 1,2-Br shift product is formed in some cases. The reaction is suggested to proceed by C–Br bond homolysis to give a radical pair, followed by disproportionation and conjugate addition of HBr to the α,β-unsaturated ketone intermediate. When the unsaturated intermediate is stabilized by an extra conjugation, the reaction stops at the stage, in which the unsaturated ketone becomes a major product. The synthetic method described in this research fits in a category of eco-friendly organic synthesis nicely since the reaction does not use volatile organic solvents and any other additives such as acid, base or metal catalysts, etc. Besides, the method fits into perfect atom economy, which does not give any side products. The synthetic method should find much advantage over other alternative methods to obtain β-bromo carbonyl compounds.
Preparation method of bupropion hydrochloride
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Page/Page column 5-7, (2018/10/19)
The invention discloses a preparation method of bupropion hydrochloride. M-chlorophenylacetone is used as a raw material to take bromination reaction with sodium bromide, sulfuric acid and hydrogen peroxide in a water-halohydrocarbon solvent to prepare a brominated intermediate; then the prepared bromide reacts with tert-butylamine to prepare amfebutamone, after the reaction for preparing amfebutamone is completely reacted, the water is directly added, after a reaction solution is layered, the layered organic layer is cleaned and distilled to obtain amfebutamone, and obtained amfebutamone is acidified by virtue of isopropanol hydrochloride to obtain bupropion hydrochloride; and the peparation process of amfebutamone, the alkalinity of a water layer obtained after the layering of the reaction solution is adjusted by using sodium hydroxide, after tert-butylamine is recovered in a distillation manner, the water layer comprising bromine ions is concentrated, the pH value is adjusted to beneutral by using sulfuric acid, the obtained aqueous solution comprising sodium bromide is used for taking the bromination reaction again so as to be circularly utilized. By adopting the preparation method, the environment-friendly circular utilization of bromine is realized, and the production cost is reduced.
Enantioselective and Diastereoselective Construction of Chiral Amino Alcohols by Iridium-f-Amphox-Catalyzed Asymmetric Hydrogenation via Dynamic Kinetic Resolution
Wu, Weilong,You, Cai,Yin, Congcong,Liu, Yuanhua,Dong, Xiu-Qin,Zhang, Xumu
supporting information, p. 2548 - 2551 (2017/05/24)
The iridium-f-amphox-catalyzed asymmetric hydrogenation of racemic α-amino β-unfunctionalized ketones proceeds via a DKR (dynamic kinetic resolution) process for the construction of various chiral N,N-disubstituted α-amino β-unfunctionalized alcohols in quantitative yields with excellent enantioselectivities and diastereoselectivities (all products >99% ee and >99:1 dr, TON up to 100 000). Importantly, this catalytic asymmetric hydrogenation with a DKR process provided a highly efficient and powerful synthetic strategy for the preparation of key chiral intermediates of the preclinical antitumor agent (S,S)-R116010.
1,3-Dibromo-5,5-dimethylhydantoin (DBH) mediated one-pot syntheses of α-bromo/amino ketones from alkenes in water
Xu, Senhan,Wu, Ping,Zhang, Wei
, p. 11389 - 11395 (2016/12/18)
α-Bromo ketones are versatile intermediates of high practical utility. Traditional approaches to these compounds are restricted to a relatively hazardous/complex reagent combination, a long reaction time, the use of non-environmentally friendly solvents, or a limited substrate scope. Herein, we describe the development of a new methodology for the preparation of α-bromo ketones from alkenes using 1,3-dibromo-5,5-dimethylhydantoin (DBH) as a bromine source and an oxidant simultaneously. This easy to carry out two-step one-pot protocol proceeds in water and provides high yield of a great variety of α-bromo ketones. Addition of an amine to the intermediate α-bromo ketone further enables the preparation of α-amino ketones in a one-pot sequence.
Aq HBr–NaNO2–KI/air: a new catalytic system for α-monobromination of ketones
Ghorpade, Archana K.,Huddar, Sameerana N.,Akamanchi, Krishnacharya G.
supporting information, p. 4918 - 4921 (2016/10/22)
An efficient approach for α-bromination of aryl alkyl ketones, utilizing a system consisting of aqueous hydrobromic acid as bromine source, sodium nitrite–KI as catalyst, and air as terminal oxidant, has been developed. The method offers advantages of selective monobromination, mild reaction conditions, broad substrate scope, and good yield. The use of air as the terminal oxidant makes the reaction very attractive from both economical and environmental viewpoints.
