Synthesis, properties, and perspectives of gem-diphosphono substituted-thiazoles
摘要:
A series of substituted arylidene thiazoles were allowed to react with Wittig-Homer (WH) reagent, tetraethyl methyl-1,1-bisphosphonate, to produce via Michael addition reaction the corresponding heteroarylmethylenebisphosphonates (BPs) in different yields according to the experimental conditions. Acid hydrolysis of the new BPs was undertaken to obtain the corresponding bisphosphonic acids. Prediction and the in vivo activity of the products in the rat adjuvant model are also discussed in terms of structure-activity relationships (SAR). (C) 2007 Elsevier Masson SAS. All rights reserved.
Nano-Fe<sub>3</sub>O<sub>4</sub>Encapsulated-Silica Particles Bearing 3-Aminopropyl Group as a Magnetically Separable Catalyst for Efficient Knoevenagel Condensation of Aromatic Aldehydes with Active Methylene Compounds
Knoevenagel condensation of aromaticaldehydes with active methylene compounds such as malononitrile, ethylcyanoacetate, benzimidazol‐2‐acetonitrile and benzothiazole‐2‐acetonitrile proceeded very smoothly, catalyzed by nano‐Fe3O4 encapsulated‐silica particles supported primary amine. Both reaction time and yield are satisfying. The advantages of this catalyst are ease of preparation, non‐toxicity
纳米Fe 3 O 4包封的二氧化硅颗粒负载的伯胺催化了芳香醛与丙二醛,丙二酸咪唑-2-乙腈和苯并噻唑-2-乙腈等活性亚甲基化合物的Knoevenagel缩合反应。反应时间和产率都令人满意。该催化剂的优点是易于制备,无毒,成本低,易于处理和可回收利用。
Choline Chloride and Urea Based Eutectic Solvents: Effective Catalytic Systems for the Knoevenagel Condensation Reactions of Substituted Acetonitriles
The Knoevenagel condensation of aromatic aldehydes with active methylene compounds such as malononitrile, ethyl cyanoacetate, benzimidazole-2-acetonitrile and benzothiazole-2-acetonitrile proceeded very smoothly, in a reusable and cheap choline chloride and urea based deep eutectic solvents. Both reaction time and yield are satisfactory. The advantages of this catalyst are that it is readily available
Synthesis, characterization and evaluation of novel benzothiazole clubbed chromene derivatives for their anti-inflammatory potential
作者:Divyani Gandhi、Dinesh Kr. Agarwal、Priyanka Kalal、Amit Bhargava、Dinesh Jangid、Shikha Agarwal
DOI:10.1080/10426507.2018.1514502
日期:2018.12.2
chromene derivatives (5a–f) were prepared by multistep synthesis process using 2-[3-phenyl prop-2-ene nitrile] 1,3-benzothiazole and dimedone using piperidine as catalyst in ethanol. The reaction was found to proceed via Knoevenagel condensation of aldehydes with benzothiazole, followed by the elimination to afford the 2-(benzo[d]thiazol-2-yl)-3-(aryl)acrylonitrile, which then undergoes Michael addition
Highly stereoselective synthesis of cyclopropyl heterocycles<i>via</i>cyclopropanation of olefin with arsonium salt
作者:Zhongjiao Ren、Weiguo Cao、Weiqi Tong、Jie Chen、Changqing Wang
DOI:10.1002/jhet.5570450105
日期:2008.1
An efficient and highlystereoselective approach for the preparation of highly functionalized cyclopropyl heterocycles via the cyclopropanation of olefines with arsonium salts in the presence of KF2H2O has been developed.
Highly diastereoselective synthesis of benzothiazolo[3,2-<i>a</i>]pyridines <i>via</i> [4 + 2] annulation reaction of 2-vinylbenzothiazoles and azlactones
benzothiazolo[3,2-a]pyridinederivatives was readily obtained in good to excellent yields (68–96%), with high diastereoselectivities and tolerating quite a broad scope of substituents. By using chiral phosphoric acid catalyst, the desired products were obtained in high enantioselectivities, up to −94%. This methodology provides a rapid and useful method for constructing fused benzothiazole derivatives.