Synthesis of 5-aryl-3H-[1,3,4]oxadiazol-2-ones from N′-(chloro-aryl-methylene)-tert-butylcarbazates using basic alumina as an efficient and recyclable surface under solvent-free condition
摘要:
The synthesis of biologically important 5-aryl-3H-[1,3,4]oxadiazol-2-ones has been carried out by heating the easily synthesized N'-(chloro-aryl-methylene)-tert-butylcarbazates on basic alumina surface under solvent-free condition. The dual characteristic of basic alumina as a solid support as well as a nucleophile is successfully exploited in these reactions. The method provides special attributions such as reduced reaction times, easier work-up procedures, and good to excellent yields as well as increased purity of products and most importantly environmentally friendly protocols. The basic alumina is easily recovered and utilized for further reactions several times without serious loss of activity. (C) 2012 Elsevier Ltd. All rights reserved.
Design and structure–activity relationship of thrombin inhibitors with an azaphenylalanine scaffold: potency and selectivity enhancements via P2 optimization
provides an enhanced fit into this activesite S2 pocket. In the present paper, we also report on the structure of these inhibitors in solution and conformational analysis of inhibitors in the activesite in order to asses the consequences of the replacement of the central alpha-CH by a nitrogen functionality. In vitro biological testing of the designedinhibitors shows that elimination of R, S stereoisomerism
The continuous-flow synthesis of carbazate hydrazones using a simplified computer-vision controlled liquid–liquid extraction system
作者:Matthew O’Brien、Dennis A. Cooper、Panashe Mhembere
DOI:10.1016/j.tetlet.2016.10.018
日期:2016.11
A computer-vision controlled liquid–liquidextractionsystem was used in the continuous-flow synthesis of a series of carbazate hydrazones. The systemuses open-source software components (Python, OpenCV) and is simpler and potentially more economical, in terms of hardware, than one we have described previously.
A series of azaphenylalanine derivatives were investigated as novel thrombin inhibitors based on the prodrug principle. By systematic structural modifications we have identified optimal groups for this series that led us to potent inhibitors of thrombin incorporating the benzamidine fragment at the PI position, and their potentially orally active benzamidoxime prodrugs. The binding modes in the thrombin active site of two representative compounds were identified by X-ray crystallographic analysis. (C) 2004 Published by Elsevier Ltd.