5049-61-6Relevant articles and documents
Green Synthesis and Antimicrobial Activity of Some Novel N-Arylimidazo[1,2-a]pyrazine-2-Carboxamide Derivatives
Jyothi, Boggavarapu,Madhavi, Nannapaneni
, p. 84 - 90 (2020)
The article deals with the synthesis of some novel N-arylimidazo[1,2-a]pyrazine-2-carboxamides (7a-l) by condensation reaction of imidazo[1,2-a]pyrazine-2-carboxylic acid (5) with different aliphatic/aromatic amines (6a-l) by using 1-methylimidazole, Mukaiyama’s reagent and 2-chloro-1-methylpyridinium iodide under microwave irradiation conditions. A new series of compounds 7 have been prepared from 2-iodopyrazine (1). Compound 1 on purged with ammonia gas in the presence of Cu2O and K2CO3 furnishes pyrazin-2-amine (2), which is treated with ethyl 3-bromo-2-oxopropanoate (3) to produce ethyl imidazo[1,2-a]pyrazine-2-carboxylate (4), which on hydrolysis with NaOH yields imidazo[1,2-a]pyrazine-2-carboxylic acid (5). The structures of the newly synthesized compounds have been elucidated on the basis of spectral (IR, 1H and 13C NMR and MS) and analytical data. Compounds 7a-l have also been screened for their antimicrobial activity. Some of the compounds exhibit promising antimicrobial activity.
C2-Selective, Functional-Group-Divergent Amination of Pyrimidines by Enthalpy-Controlled Nucleophilic Functionalization
Ham, Won Seok,Choi, Hoonchul,Zhang, Jianbo,Kim, Dongwook,Chang, Sukbok
supporting information, p. 2885 - 2892 (2022/02/23)
Synthesis of heteroaryl amines has been an important topic in organic chemistry because of their importance in small-molecule discovery. In particular, 2-Aminopyrimidines represent a highly privileged structural motif that is prevalent in bioactive molecules, but a general strategy to introduce the pyrimidine C2-N bonds via direct functionalization is elusive. Here we describe a synthetic platform for site-selective C-H functionalization that affords pyrimidinyl iminium salt intermediates, which then can be transformed into various amine products in situ. Mechanism-based reagent design allowed for the C2-selective amination of pyrimidines, opening the new scope of site-selective heteroaryl C-H functionalization. Our method is compatible with a broad range of pyrimidines with sensitive functional groups and can access complex aminopyrimidines with high selectivity.
Novel method for synthesizing 2- amino -3,5- dibromopyrazine as well as product and application thereof
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Paragraph 0042; 0060-0061; 0066; 0071; 0077; 0078, (2020/03/25)
The invention discloses a novel method 2 - for synthesizing, amino - 333355-dibromopyrazine by reacting, with,aminopyrazine 2 - sodium hypochlorite as a raw material, and adding, amino-pyrazino,dibromopyrazine 2 - in ;amino - 3333,5-dibromopyrazine as a raw material by, hours N,N - to obtain,aminopypyrazine 1,3 - in step, as a solvent 2 - and dropping under reduced pressure. N,N - The present invention provides a novel method for synthesizing, amino-3,5-dibromopyrazine as a crude product 15 - 20 in a reduced pressure distillation condition . The present invention. discloses a process 2 - for the preparation of the product. 2 - The present invention discloses 2 - N - 3333,5-dibromopyrazino, crude, obtained by the present, invention is added dropwise to prepare 2 - lamino - 3333.5-dibromopyrazine.
Preparation method of 2-amino substituted six-membered nitrogen-containing heterocycle complex
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Paragraph 0025; 0026; 0109, (2019/02/08)
The invention discloses a preparation method of a 2-amino substituted six-membered nitrogen-containing heterocycle complex. The preparation method comprises the following steps: mix 2-fluorine substituted six-membered nitrogen-containing heterocycle complex and amidine hydrochloride salt compound, and then react under the action of a alkaline substance to obtain a 2-amino substituted six-memberednitrogen-containing heterocycle complex. Preferably, the 2-amino substituted six-membered nitrogen-containing heterocycle complex is a 2-amino pyridine compound, a 2-aminopyrimidine compound or a 2-aminopyrazine compound. Compared with the prior art, the method has the advantages of simple synthesis conditions, less reaction steps, mild reaction conditions, low cost of the catalyst used, less waste discharge and good functional group tolerance.
Diverse Oxidative C(sp2)-N Bond Cleavages of Aromatic Fused Imidazoles for Synthesis of α-Ketoamides and N-(pyridin-2-yl)arylamides
Xu, Fangzhou,Wang, Yanyan,Xun, Xiwei,Huang, Yun,Jin, Zhichao,Song, Baoan,Wu, Jian
, p. 8411 - 8422 (2019/05/17)
An efficient and chemoselective C(sp2)-N bond cleavage of aromatic imidazo[1,2-a]pyridine molecules is developed. A broad scope of amide compounds such as α-ketoamides and N-(pyridin-2-yl)arylamides are afforded as the final products in up to quantitative yields. Diverse C-N bond cleavages are controlled by the oxidative species used in this transformation, with various amide products afforded in a chemoselective fashion. A preliminary study indicated that some α-ketoamides exhibit anti-Tobacco Mosaic Virus activity for potential use in plant protection.
Copper-catalyzed arene amination in pure aqueous ammonia
Takagi, Mio,Watanabe, Ayako,Murata, Shigeo,Takita, Ryo
supporting information, p. 1791 - 1795 (2019/02/20)
A simple protocol for copper-catalyzed arene amination using aqueous ammonia without any additional ligands and organic coordinating solvents has been developed. The reaction pathway via a Cu(i)/Cu(iii) mechanism is proposed based on the results of control experiments as well as DFT calculations.
Aromatic amine compound synthesis method
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Paragraph 0251-0253, (2019/01/23)
The invention discloses an aromatic amine compound synthesis method which is characterized in that the method is implemented according to any of two methods. The first method includes the steps: mixing an alkyl aromatic compound with a general formula (I) and a nitrogen-containing compound with a general formula (II); performing reaction on mixture under an oxidizing agent and an organic solvent to obtain an aromatic amine compound with a general formula (III). The second method includes the steps: mixing an aromatic alcohol derivative with a general formula (I') and the nitrogen-containing compound with the general formula (II); performing reaction on mixture under an acid additive and an organic solvent to prepare the aromatic amine compound with the general formula (III). According to the method, a lot of alkyl aromatic compounds or aromatic alcohol derivatives firstly serve as raw materials, and the raw materials are reacted to generate the aromatic amine compound without the action of metal catalysis. Compared with a traditional synthesis method, the synthesis method has the advantages that the method is high in yield and simple in condition, waste discharging amount is less,metal participation is omitted, a reaction device is simple, industrial production is easily achieved and the like. The method has a wide application prospect.
Transition-metal-free access to 2-aminopyridine derivatives from 2-fluoropyridine and acetamidine hydrochloride
Li, Yibiao,Huang, Shuo,Liao, Chunshu,Shao, Yan,Chen, Lu
supporting information, p. 7564 - 7567 (2018/11/02)
Under catalyst-free conditions, an efficient method for the synthesis of 2-aminopyridine derivatives through the nucleophilic substitution and hydrolysis of 2-fluoropyridine and acetamidine hydrochloride has been developed. This amination uses inexpensive acetamidine hydrochloride as the ammonia source and has the advantages of a high yield, high chemoselectivity and wide substrate adaptability. The results suggest that other N-heterocycles containing fluorine substituents can also complete the reaction via these reaction conditions and yield the target products.
A 2 - amino pyrazine derivatives of preparation method
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Paragraph 0012; 0013; 0014, (2018/10/19)
The invention discloses a 2 - amino pyrazine derivatives of preparation method, comprises the following steps: C1: to 2 - cyano pyrazine is sequentially added in the sodium hypochlorite solution and alkali, then stirring, to obtain 2 - amino pyrazine; C2: step C1 of the obtained 2 - amino pyrazine join the brominating agent performing the bromination reaction, to obtain 2 - amino - 3, 5 - two bromine pyrrole qin; C3: step C2 of the obtained 2 - amino - 3, 5 - two bromine pyrrole qin with morpholine substitution reaction to obtain 2 - amino - 5 - bromo - 3 - morpholinyl pyrazine solution; C4: the 2 - amino - 5 - bromo - 3 - morpholinyl [...] is distilled out of the organic solvent, then wash the static separation, to obtain 2 - amino - 5 - bromo - 3 - morpholinyl pyrazine crude product. In order to 2 - cyano pyrazine as raw materials, is easy to prepare or procurement, after acid-base reaction, bromination reaction, the substitution reaction, distillation filtering and the like four-step operation preparation, preparation method is simple and convenient operation, the final preparation of the obtained 2 - amino pyrazine derivatives have high yield, is suitable for industrial production.
Selective Cross-Coupling of (Hetero)aryl Halides with Ammonia to Produce Primary Arylamines using Pd-NHC Complexes
Lombardi, Christopher,Day, Jonathan,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Farmer, Jennifer L.,Organ, Michael G.
supporting information, p. 251 - 254 (2017/04/26)
Herein we report the first example of (hetero)arylation of ammonia using a monoligated palladium-NHC complex. The new, rationally designed, precatalyst (DiMeIHeptCl)Pd(allyl)Cl featuring highly branched alkyl chains has been shown to be effective in selective aminations across a range of challenging substrates, including nitrogen-containing heterocycles and those featuring base-sensitive functionality. The less bulky Pd-PEPPSI-IPentCl precatalyst performs well for ortho-substituted aryl halides, giving monoarylated products in high yield with good selectivity.