6298-19-7Relevant articles and documents
Palladium Immobilized on a Polyimide Covalent Organic Framework: An Efficient and Recyclable Heterogeneous Catalyst for the Suzuki–Miyaura Coupling Reaction and Nitroarene Reduction in Water
Dong, Zhenhua,Pan, Hongguo,Gao, Pengwei,Xiao, Yongmei,Fan, Lulu,Chen, Jing,Wang, Wentao
, p. 299 - 306 (2021/05/10)
An efficient and recyclable Pd nano-catalyst was developed via immobilization of Pd nanoparticles on polyimide linked covalent organic frameworks (PCOFs) that was facilely prepared through condensation of melamine and 3,3′,4,4′-biphenyltetracarboxylic dianhydride. The Pd nanoparticles (Pd NPs) catalyst was thoroughly characterized by FT-IR, XRD, SEM, TEM. Furthermore, the catalytic activity of Pd NPs catalyst was evaluated by Suzuki–Miyaura coupling reaction and nitroarene reduction in water, respectively. The excellent yields of corresponding products revealing revealed that the Pd NPs catalyst could be applied as an efficient and reusable heterogeneous catalyst for above two reactions. Graphical Abstract: [Figure not available: see fulltext.]
Industrial Cunninghamia lanceolata carbon supported FeO(OH) nanoparticles-catalyzed hydrogenation of nitroarenes
Fu, Lihua,Li, Dingzhong,Lu, Hao,Qiu, Renhua,Sun, Tulai,Xing, Chen,Yang, Tianbao
, (2022/01/11)
The development of green and efficient methods for hydrogenation of nitroarenes is still highly demanding in organic synthesis. Herein, we report an industrial Cunninghamia lanceolata carbon supported FeO(OH) nanoparticles process for the synthesis of aryl amines with good yields via hydrogenation of nitroarenes. Nine key anti-cancer drug intermediates were successfully achieved with protocol. And Osimertinib intermediate 4m can be smoothly synthesized at a 2.67 kg-scale with >99.5% HPLC purity. This protocol features cheap carbon source, highly catalytic activity, simple operation, kilogram-scalable and recyclable catalysts (eight times without observable losing activity).
Efficient and recyclable bimetallic Co–Cu catalysts for selective hydrogenation of halogenated nitroarenes
Lu, Xionggang,Ren, Jiaan,Sheng, Yao,Wang, Xueguang,Wu, Baoqin,Zou, Xiujing
, (2021/12/20)
Silica supported N-doped carbon layers encapsulating Co–Cu nanoparticles (Co1Cux@CN/SiO2) were prepared by a one-step impregnation of Co(NO3)2·6H2O, Cu(NO3)2·3H2O, urea and glucose, following in situ carbothermal reduction. Effects of Cu contents on the catalytic performance of the Co1Cux@CN/SiO2 catalysts were investigated for selective hydrogenation of p-chloronitrobenzene to p-chloroaniline. The Co1Cu0.30@CN/SiO2 with Cu/Co molar ratio of 0.30:1 presented much higher activity and stability than the monometallic Co@CN/SiO2 catalyst. The addition of Cu into Co1Cux@CN/SiO2 catalysts had favorable effects on the formation of highly active Co–N sites and N-doped carbon layer. The role of the N-doped carbon layer was to protect the Co from oxidation by air, and the Co1Cu0.30@CN/SiO2 could be reused for at least 12 cycles without decrease in catalytic efficiency. Mechanistic and in situ infrared studies revealed that the interaction effect between the Co and Cu atoms made the surface of Co highly electron rich, which decreased adsorption of halogen groups and resulting in the enhanced selectivity during chemoselective hydrogenation of halogenated nitroarenes for a wide scope of substrates.
METHOD OF REDUCING AROMATIC NITRO COMPOUNDS
-
Paragraph 0332; 0345, (2022/02/26)
A method for reducing a substrate selected from 2-methyl-5-nitropyridine and methyl 4-(2-fluoro-3-nitrobenzyl)piperazine-1-carboxylate is provided catalysed by a nitroreductase and a disproportionation agent.
Method for preparing 2, 3 -dichloropyridine from chlorination
-
Paragraph 0011; 0049-0054; 0057-0058, (2021/11/03)
The invention relates to a method for preparing 2 and 3 - dichloropyridine from chlorination. The method introduces the graphene oxide catalyst in the traditional 3 - aminopyridine chlorination step, reduces the concentration and the dosage of hydrochloric acid and hydrogen peroxide, improves the selectivity of 2 -position chlorination, and reduces the generation of 2, 6 - dichloro -3 - aminopyridine. , The process enables high yield to obtain 2 - chloro -3 - aminopyridines of higher quality. , The method has good environmental friendliness and economical efficiency, and is suitable for being popularized and used in industry.
NaI/PPh3-Mediated Photochemical Reduction and Amination of Nitroarenes
Qu, Zhonghua,Chen, Xing,Zhong, Shuai,Deng, Guo-Jun,Huang, Huawen
supporting information, p. 5349 - 5353 (2021/07/21)
A mild transition-metal- and photosensitizer-free photoredox system based on the combination of NaI and PPh3 was found to enable highly selective reduction of nitroarenes. This protocol tolerates a broad range of reducible functional groups such as halogen (Cl, Br, and even I), aldehyde, ketone, carboxyl, and cyano. Moreover, the photoredox catalysis with NaI and stoichiometric PPh3 provides also an alternative entry to Cadogan-type reductive amination when o-nitrobiarenes were used.
Preparation method 2-chloro -3- aminopyridine
-
Paragraph 0070-0084; 0092; 0096-0098, (2020/03/29)
The organic phase 2 - separates the organic phase and the aqueous phase in, steps: first and continuously pumps, aminopyridine hydrochloride in a hydrochloric acid solution and uniformly mixes; the organic phase containing 3 - aminopyridine hydrochloride solution, with an organic solvent 3 - chlorination reagent solution to obtain, chlorine - 3 3-aminopyridine solution, in a continuous pump in a sample stage extraction centrifuge as a sample stage extraction centrifuge; to extract a centrifuge. 2nd. The present invention uses ", continuous process; to prepare,aminopyridine as a present stage extraction centrifuge, in a continuous pump in a two-stage extraction centrifuge as a present stage extraction centrifuge, to extract a centrifuge, in a stage extraction, centrifuge as a. fourth present-stage extraction centrifuge, and continuously pump second the organic phase with the aqueous, phase separation, 2 - organic phase "; step. third by a continuous pump in a. stage extraction centrifuge as a present stage extraction centrifuge, to separate the organic phase and the organic phase.
Preparation method of medical intermediate 2-chloro-3-aminopyridine
-
Paragraph 0025; 0032-0033; 0034; 0041-0042; 0043; 0047-0051, (2020/11/26)
The invention discloses a preparation method of a medical intermediate, namely 2-chloro-3-aminopyridine. The preparation method comprises the following steps: S1, preparation of nicotinamide; S2, preparation of 3-aminopyridine; S3, preparation of a crude product of 2-chloro-3-aminopyridine; and S4, refining. The method has the advantages of usage of easily available raw materials, low price, mildreaction conditions, easy product separation, high purity, high yield, less three wastes and small pollution, and is suitable for large-scale production. According to the method, dangerous and expensive raw materials such as chlorine and zinc powder are prevented from being used, so industrial application prospects are achieved; and ethyl acetate, toluene and dichloromethane are adopted as organicsolvents, and can be recycled.
Photochemical synthesis method of heteroarylamine compounds
-
Paragraph 0067, (2020/10/14)
The invention provides a photochemical synthesis method of heteroarylamine compounds. The photochemical synthesis method comprises the following steps: S1, mixing raw materials including heteroaryl nitro compounds, a solvent and a photocatalyst to obtain a mixture; and S2, carrying out a photocatalytic reduction reaction on the mixture under an illumination condition to obtain a product system containing the heteroarylamine compounds. According to the photochemical synthesis method, photocatalytic reduction of various different heteroaryl nitro compounds is achieved under the illumination condition, and the high-yield heteroaryl amine compounds are obtained. The photocatalyst is an existing common catalyst, has no strict requirements on equipment and is easy to recover, and the safety riskof the heteroarylamine compound and the catalyst cost are reduced. Any metal reagent and reducing agent do not need to be added in the whole reaction process of photocatalysis, the reaction conversion rate is high, and post-treatment is simple and easy to operate, so the method is safer and more environmentally friendly.
Method for reducing aromatic nitro into arylamine
-
Paragraph 0181-0184, (2020/07/15)
The invention relates to a method for reducing aromatic nitro to arylamine. The method comprises the following steps: (1) taking an aromatic nitro compound as a raw material, water as a hydrogen source, a palladium compound, cheap and easy to obtain, as a catalyst and tetrahydroxydiboron as an additive to reduce nitro to obtain a product; (2) taking the aromatic nitro compound as the raw material, a copper salt, cheap and easy to obtain, as the catalyst, the tetrahydroxydiboron as the additive to reduce the nitro to obtain a product; and (3) taking the aromatic nitro compound as the raw material, water as the hydrogen source, and the tetrahydroxydiboron as the additive, without needing a metal catalyst, to reduce the nitro to obtain a product. A preparation method for the arylamine, which is provided by the invention, is mild in reaction condition, low in costs, environment-friendly, high in yield, and suitable for industrial production.
