621-72-7Relevant academic research and scientific papers
SOLID-PHASE REACTIONS OF AROMATIC AMINES WITH CARBOXYLIC ACIDS UNDER CONDITIONS OF SHEAR DEFORMATION AND HIGH PRESSURE
Leont'ev, A. I.,Zharov, A. A.,Chistotina, N. P.
, p. 1680 - 1684 (1992)
Solid mixtures of carboxylic acids and aromatic amines react under shear deformation at high pressure (to 8 GPa) for form amides, in the case of ortho-phenylenediamine-substituted benzimidazoles are formed.Under these conditions the conversion rates are hundreds of thousands of times higher than when the same processes are carried out in liquid phase.The cyclization reaction is accelerated to a lesser degree than the reaction of formation of the corresponding amide.The increase of the length of the carboxylic acid radical prevents the cyclization reaction. Keywords: shear deformation, high pressure, aromatic amines, carboxylic acids, amide, benzimidazole, amidization, cyclization.
Design, synthesis, and evaluation of different scaffold derivatives against NS2B-NS3 protease of dengue virus
Ganji, Lata R.,Gandhi, Lekha,Musturi, Venkataramana,Kanyalkar, Meena A.
, p. 285 - 301 (2020/11/19)
The number of deaths or critical health issues is a threat in the infection caused by Dengue virus, which complicates the situation, as only symptomatic treatment is the current solution. In this regard we have targeted the dengue protease NS2B-NS3 that is responsible for the replication. The series was designed with the help of molecular modeling approach using docking protocols. The series comprised of different scaffolds viz. cinnamic acid analogs (CA1–CA11), chalcone (C1–C10) and their molecular hybrids (Lik1–Lik10), analogs of benzimidazole (BZ1-BZ5), mercaptobenzimidazole (BS1-BS4), and phenylsulfanylmethylbenzimidazole (PS1-PS4). Virtual screening of various natural phytoconstituents was employed to determine the interactions of designed analogs with the residues of catalytic triad in the active site of NS2B-NS3. We have further synthesized the selected leads. The synthesized analogs were evaluated for the cytotoxicity and NS2B-NS3 protease inhibition activity and compared with known anti-dengue natural phytoconstituent quercetin as the standard. CA2, BZ1, and BS2 were found to be more potent and efficacious than the standard quercetin as evident from the protease inhibition assay.
Simple inorganic base promoted C-N and C-C formation: synthesis of benzo[4,5]imidazo[1,2-a]pyridines as functional AIEgens used for detecting picric acid
Yang, Kai,Luo, Shi-He,Chen, Si-Hong,Cao, Xi-Ying,Zhou, Yong-Jun,Lin, Yan-Lan,Huo, Yan-Ping,Wang, Zhao-Yang
supporting information, p. 8133 - 8139 (2021/10/04)
Metal-free catalyzed intermolecular tandem Michael addition/cyclization has been developed for the synthesis of benzo[4,5]imidazo[1,2-a]pyridines from α-bromocinnamaldehyde and 2-substituted benzimidazoles. The reaction promoted by a simple inorganic base displays moderate to good yields and good functional group tolerance. The optical properties of some typical products have been investigated. We found that, due to the presence of the benzene ring at the C1-position of benzo[4,5]imidazo[1,2-a]pyridines which restricts intramolecular motion, as a new type of aggregation-induced emission (AIE) luminogen (AIEgen), they show very good solid-state fluorescence with quantum yields up to 88.80%. Importantly, the AIE performance of compound3bcan be useful to detect the nitroaromatic explosive picric acid (PA) with a detection limit and quenching constant of 42.5 nM and 7.27 × 104M?M, respectively.
Preparation method 2 -substituted benzimidazole derivative
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Paragraph 0053-0058, (2021/11/10)
The invention belongs to the field of fine chemical product production, and particularly relates to 2 -substituted benzimidazole derivative preparation method which comprises the following steps: (1) taking O-phenylenediamine and aldehyde as raw materials, carrying out catalytic condensation, cyclization and oxidation reaction in a eutectic solvent. (2) Water is added to the reaction system, the separated product is filtered, and the eutectic solvent is recycled. (3) After recrystallization, a target product is obtained. The method has the advantages of simple operation process, easily available raw materials, low cost, high purity of the target product and no catalyst participation, can effectively prevent isomer formation, and is beneficial to large-scale production.
s-Tetrazine-functionalized hyper-crosslinked polymers for efficient photocatalytic synthesis of benzimidazoles
An, Wan-Kai,Zheng, Shi-Jia,Zhang, Hui-Xing,Shang, Tian-Tian,Wang, He-Rui,Xu, Xiao-Jing,Jin, Qiu,Qin, Yuchen,Ren, Yunlai,Jiang, Song,Xu, Cui-Lian,Hou, Mao-Song,Pan, Zhenliang
supporting information, p. 1292 - 1299 (2021/02/26)
Developing green-safe, efficient and recyclable catalysts is crucial for the chemical industry. So far, organic photocatalysis has been proved to be an environmentally friendly and energy-efficient synthetic technology compared with traditional metal catalysis. As a versatile catalytic platform, hyper-crosslinked polymers (HCPs) with large surface area and high stability are easily prepared. In this report, we successfully constructed two porous HCP photocatalysts (TZ-HCPs) featurings-tetrazine units and surface areas larger than 700 m2g?1through Friedel-Crafts alkylation reactions. The rational energy-band structures and coexisting micro- and mesopores endow TZ-HCPs with excellent activities to realize the green synthesis of benzimidazoles (28 examples, up to 99% yield, 0.5-4.0 h) in ethanol. Furthermore, at least 21 iterative catalytic runs mediated by TZ-HCP1D were performed efficiently, with 96-99% yield. This study of TZ-HCPs sheds light on the wide-ranging prospects of application of HCPs as metal-free and green photocatalysts for the preparation of fine chemicals.
Regioselective, Diastereoselective, and Enantioselective One-Pot Tandem Reaction Based on an in Situ Formed Reductant: Preparation of 2,3-Disubstituted 1,5-Benzodiazepine
Yang, Gao-Feng,Li, Guang-Xun,Huang, Jin,Fu, Ding-Qiang,Nie, Xiao-Kang,Cui, Xin,Zhao, Jin-Zhong,Tang, Zhuo
, p. 5110 - 5119 (2021/04/12)
The 1,5-benzodiazepines are important skeletons frequently contained in medicinal chemistry. Herein, we described an unexpected tandem cyclization/transfer hydrogenation reaction for obtaining chiral 2,3-disubstituted 1,5-benzodiazepines. The enolizable aryl aldehydes were chosen as substrates to react with symmetric and unsymmetric o-phenylenediamines. The unforeseen tandem reaction occurred among many possible latent side reactions under chiral phosphoric acid catalysis and affords the corresponding products in moderate yields and regioselectivities, good diastereoselectivities, and enantiomeric ratio (up to 99:1).
Nickel catalysed construction of benzazoles: Via hydrogen atom transfer reactions
Adhikari, Debashis,Bains, Amreen K.,Dey, Dhananjay,Kundu, Abhishek,Yadav, Sudha
, p. 6495 - 6500 (2020/11/13)
Herein we report a homogeneous, phosphine free, inexpensive nickel catalyst that forms a wide variety of benzazoles from alcohol and diamines by a reaction sequence of alcohol oxidation, imine formation, ring cyclization and dehydrogenative aromatization. A reversible azo/hydrazo couple, that is part of the ligand architecture steers both the alcohol oxidation and dehydrogenation of the annulated amine under fairly mild reaction conditions. Interestingly, both the alcohol oxidation and amine dehydrogenation steps are directly mediated by hydrogen atom transfer (HAT), which is greatly facilitated by the reduced ligand backbone. The kH/kD for the amine dehydrogenation step, measured at 60 °C is 5.9, fully consistent with HAT as the rate determining factor during this step. This is a unique scenario where two consecutive oxidation steps towards benzazole formation undergo HAT, which has been substantiated via kinetic studies, KIE determination and intermediate isolation. This journal is
Synthesis method of benzimidazole derivative
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Paragraph 0029; 0030, (2019/04/10)
The invention discloses a synthesis method of a benzimidazole derivative. The method comprises the following steps: o-phenylenediamine or a derivative thereof and phenylacetic acid or a derivative ofthe phenylacetic acid are used as raw materials, a composite solid catalyst is adopted, and a high-boiling-point organic solvent is taken as a reaction solvent for carrying out a reaction at 100-130 DEG C for 4-8 hours; and distillation, dissolution, neutralization, decoloration and recrystallization are carried out to obtain a benzimidazole derivative product. The method has the advantages that operation is simple, the reaction time is greatly shortened, the product color is good, the yield is high, cost is low, pollution is low, environment friendliness is achieved, and the like, and has a very good industrial production application prospect.
Green synthesis of privileged benzimidazole scaffolds using active deep eutectic solvent
Gioia, Maria Luisa Di,Cassano, Roberta,Costanzo, Paola,Cano, Natividad Herrera,Maiuolo, Loredana,Nardi, Monica,Nicoletta, Fiore Pasquale,Oliverio, Manuela,Procopio, Antonio
supporting information, (2019/08/20)
The exploitation and use of alternative synthetic methods, in the face of classical procedures that do not conform to the ethics of green chemistry, represent an ever-present problem in the pharmaceutical industry. The procedures for the synthesis of benzimidazoles have become a focus in synthetic organic chemistry, as they are building blocks of strong interest for the development of compounds with pharmacological activity. Various benzimidazole derivatives exhibit important activities such as antimicrobial, antiviral, anti-inflammatory, and analgesic activities, and some of the already synthesized compounds have found very strong applications in medicine praxis. Here we report a selective and sustainable method for the synthesis of 1,2-disubstituted or 2-substituted benzimidazoles, starting from o-phenylenediamine in the presence of different aldehydes. The use of deep eutectic solvent (DES), both as reaction medium and reagent without any external solvent, provides advantages in terms of yields as well as in the work up procedure of the reaction.
Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon
Wang, Zhaozhan,Song, Tao,Yang, Yong
supporting information, p. 319 - 324 (2019/02/12)
A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.
