621-72-7Relevant articles and documents
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.
SYNTHESIS OF DIBAZOLE IN THE SOLID PHASE UNDER HIGH PRESSURE AND SHEAR STRESS
Chistotina, N. P.,Zharov, A. A.,Agafonov, N. E.,Bogdanov, V. S.
, p. 1333 (1989)
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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.
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.
