4190-14-1Relevant academic research and scientific papers
Muricatisine - A new alkaloid from two species of Oxytropis
Demeuov,Akhmedzhanova,Moldagulov,Shakirov
, p. 484 - 491 (1998)
The new alkaloid muricatisine has been isolated from the epigeal parts of the plants Oxytropis muricata (Pall.) DC. (Mongolia) and O. puberula Boriss. (Kazakhstan), which belong to the Fabaceae family, and its structure has been established on the basis of spectral characteristics as N-benzoyl-2-oxo-2-phenylethylamine and has been confirmed by a partial synthesis.
Synthesis method of alpha-acylamino ketone compound
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Paragraph 0020-0026; 0027-0029, (2020/12/08)
The invention discloses a synthesis method of an alpha-acylamino ketone compound, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: mixingan alkenyl azide compound 1, a carboxylic acid compound 2 and an organic solvent, and heating to react to obtain the alpha-acylamino ketone compound 3. Compared with the prior art, the method has thefollowing advantages: (1) the synthesis process is simple and efficient, no catalyst is needed in the whole process, and the alpha-acylamino ketone compound can be obtained with high yield by dissolving the alkenyl azide compound and the carboxylic acid compound in the solvent and stirring; (2) raw materials are cheap and easy to obtain, reaction conditions are mild, and operation is simple; (3) the substrate is wide in application range and can be used for modifying drug molecules; and (4) the atom economy is high, and the requirements of green chemistry are met.
Synthesis of α-Amidoketones through the Cascade Reaction of Carboxylic Acids with Vinyl Azides under Catalyst-Free Conditions
Gao, Cai,Zhou, Qianting,Yang, Li,Zhang, Xinying,Fan, Xuesen
, p. 13710 - 13720 (2020/11/13)
An efficient synthesis of α-amidoketone derivatives through the cascade reactions of carboxylic acids with vinyl azides is presented. Compared with literature protocols, notable features of this new method include catalyst-free conditions, broad substrate scope, good tolerance of a wide range of functional groups, and high efficiency. In addition, the synthetic potential of this method as a tool for late-stage modification was convincingly manifested by its application in the structural elaborations of a number of carboxylic acid drug molecules.
Site-Selective Conversion of Azido Groups at Carbonyl α-Positions to Diazo Groups in Diazido and Triazido Compounds
Yokoi, Taiki,Tanimoto, Hiroki,Ueda, Tomomi,Morimoto, Tsumoru,Kakiuchi, Kiyomi
, p. 12103 - 12121 (2018/10/09)
This paper reports on the selective conversion of alkyl azido groups at the carbonyl α-position to diazo compounds. Through β-elimination of dinitrogen, followed by hydrazone formation/decomposition, α-azidocarbonyl moieties were transformed into α-diazo carbonyl groups in one step. As these reaction conditions do not involve aryl or general alkyl azides, site-selective conversions of di- and triazides were achieved. Through this method, the successive site-selective conjugation of the triazido molecule with three different components is demonstrated.
Remote C(sp3)-H Oxygenation of Protonated Aliphatic Amines with Potassium Persulfate
Lee, Melissa,Sanford, Melanie S.
, p. 572 - 575 (2017/02/10)
This letter describes the development of a method for selective remote C(sp3)-H oxygenation of protonated aliphatic amines using aqueous potassium persulfate. Protonation serves to deactivate the proximal C(sp3)-H bonds of the amine substrates and also renders the amines soluble in the aqueous medium. These reactions proceed under relatively mild conditions (within 2 h at 80 °C with amine as limiting reagent) and do not require a transition metal catalyst. This method is applicable to a variety of types of C(sp3)-H bonds, including 3°, 2°, and benzylic C-H sites in primary, secondary, and tertiary amine substrates.
2,5-diphenyl-oxazole preparation method
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Paragraph 0026; 0027; 0036; 0038, (2019/02/04)
The invention relates to a method for preparing scintillation pure grade 2,5-diphenyl oxazole (DPO or PPO for short). The method comprises the following steps: by taking benzoyl glycine as a raw material, performing multiple steps of reaction such as acylating chlorination, Frieldel-Crafts and ring formation, purifying middle products of each step without being separated, and preparing 2,5-diphenyl oxazole by using a one-pot method. An obtained product can be rectified and purified, the requirements of a scintillator cannot be met but metal oxide heating treatment is needed, and thus a 2,5-diphenyl oxazole product for scintillation fluor can be obtained. As the one-pot method is adopted to prepare 2,5-diphenyl oxazole, the reaction steps are reduced, the operation process is simplified, the production efficiency is improved, a purification method is simple, convenient and effective, and on-scale industrialization production is achieved.
Synthesis of Multiple-Substituted Pyrroles via Gold(I)-Catalyzed Hydroamination/Cyclization Cascade
Li, Xiangdong,Chen, Ming,Xie, Xin,Sun, Ning,Li, Shi,Liu, Yuanhong
supporting information, p. 2984 - 2987 (2015/06/30)
A gold-catalyzed cascade hydroamination/cyclization reaction of α-amino ketones with alkynes to form substituted pyrroles has been developed. The method offers several advantages such as high regioselectivity with the tested cases, wide functional group tolerance, and easily accessible starting materials. The synthetic utility of the obtained pyrrole products was demonstrated by their efficient transformations to 2-vinylated pyrroles via gold-catalyzed intermolecular hydroarylation.
Base-catalyzed N -N bond cleavage of hydrazones: Synthesis of α-amino ketones
Tang, Hai-Tao,Zhou, Yun-Bing,Zhu, Yu,Sun, Hong-Chao,Lin, Min,Zhan, Zhuang-Ping
supporting information, p. 1278 - 1281 (2014/05/06)
An efficient Cs2CO3-promoted synthesis of α-amino ketones using hydrazines, aldehydes, and α-haloketones as starting materials through a cascade condensation/nucleophilic substitution/N -N bond cleavage route is developed. The carbonyl group plays a key role in this novel N -N bond cleavage process. Breaking good: A novel method of base-catalyzed N -N bond cleavage of hydrazones has been discovered. A variety of α-amino ketones was synthesized using hydrazines, α-haloketones, and benzaldehyde as starting materials through a cascade condensation/ nucleophilic substitution/N -N bond cleavage sequence.
Synthesis of novel trisubstituted imidazolines
Lakner, Frederick J.,Parker, Matthew A.,Rogovoy, Boris,Khvat, Alexander,Ivachtchenko, Alexander
experimental part, p. 1987 - 1990 (2009/12/25)
Imidazolines substituted at the 1- and either the 4-, or 5-position with phenyl and at the 2-position with alkyl or phenyl have been prepared in racemic form. They appear to be fairly stable compounds and potentially useful as scaffolds in medicinal chemistry. Georg Thieme Verlag Stuttgart.
Competition between α-cleavage and energy transfer in α-azidoacetophenones
Muthukrishnan, Sivaramakrishnan,Mandel, Sarah M.,Hackett, John C.,Singh, Pradeep N. D.,Hadad, Christopher M.,Krause, Jeanette A.,Gudmundsdottir, Anna D.
, p. 2757 - 2768 (2008/02/02)
(Chemical Equation Presented) Molecular modeling demonstrates that the first excited state of the triplet ketone (T1K) in azide 1b has a (π,π*) configuration with an energy that is 66 kcal/mol above its ground state and its second excited state (T2K) is 10 kcal/mol higher in energy and has a (n,π*) configuration. In comparison, T 1K and T2K of azide 1a are almost degenerate at 74 and 77 kcal/mol above the ground state with a (n,π*) and (π,π*) configuration, respectively. Laser flash photolysis (308 nm) of azide 1b in methanol yields a transient absorption (λmax = 450 nm) due to formation of T1K, which decays with a rate of 2.1 × 10 -5 s-1 to form triplet alkylnitrene 2b (λmax = 320 nm). The lifetime of nitrene 2b was measured to be 16 ms. In contrast, laser flash photolysis (308 nm) of azide 1a produced transient absorption spectra due to formation of nitrene 2a (λ max = 320 nm) and benzoyl radical 3a (λmax = 370 nm). The decay of 3a is 2 × 10-5 s-1 in methanol, whereas nitrene 2a decays with a rate of ～91 s-1. Thus, T 1K (π,π*) in azide 1b leads to energy transfer to form nitrene 2b; however, α-cleavage is not observed since the energy of T 2K (n,π*) is 10 kcal/mol higher in energy than T 1K, and therefore, T2K is not populated. In azide 1a both α-cleavage and energy transfer are observed from T1K (n,π*) and T2K (π,π*), respectively, since these triplet states are almost degenerate. Photolysis of azide 1a yields mainly product 4, which must arise from recombination of benzoyl radicals 3a with nitrenes 2a. However, products studies for azide 1b also yield 4b as the major product, even though laser flash photolysis of azide 1b does not indicate formation of benzoyl radical 3b. Thus, we hypothesize that benzoyl radicals 3 can also be formed from nitrenes 2. More specifically, nitrene 2 does undergo α-photocleavage to form benzoyl radicals and iminyl radicals. The secondary photolysis of nitrenes 2 is further supported with molecular modeling and product studies.
