Now showing items 1-3 of 3
| Abstract: | Multi-component reactions are effective in building complex molecules in a single step in a minimum amount of time and with facile isolation procedures; they have high economy1–7 and thus have become a powerful synthetic strategy in recent years.8–10 The multicomponent protocols are even more attractive when carried out in aqueous medium. Water offers several benefits, including control over exothermicity, and the isolation of products can be carried out by single phase separation technique. Pyranopyrazoles are a biologically important class of heterocyclic compounds and in particular dihydropyrano[2,3-c]pyrazoles play an essential role in promoting biological activity and represent an interesting template in medicinal chemistry. Heterocyclic compounds bearing the 4-H pyran unit have received much attention in recent years as they constitute important precursors for promising drugs.11–13 Pyrano[2,3-c]pyrazoles exhibit analgesic,14 anti-cancer,15 anti-microbial and anti-inflammatory16 activity. Furthermore dihydropyrano[2,3-c]pyrazoles show molluscidal activity17,18 and are used in a screening kit for Chk 1 kinase inhibitor activity.19,20 They also find applications as pharmaceutical ingredients and bio-degradable agrochemicals.21–29 Junek and Aigner30 first reported the synthesis of pyrano[2,3-c]pyrazole derivatives from 3-methyl-1-phenylpyrazolin-5-one and tetracyanoethylene in the presence of triethylamine. Subsequently, a number of synthetic approaches such as the use of triethylamine,31 piperazine,32 piperidine,33 N-methylmorpholine in ethanol,34 microwave irradiation,35,36 solvent-free conditions,37–39 cyclodextrins (CDs),40 different bases in water,41 γ -alumina,42 and l-proline43 have been reported for the synthesis of 6-amino-4-alkyl/aryl-3-methyl- 2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles. Recently, tetraethylammonium bromide (TEABr) has emerged as mild, water-tolerant, eco-friendly and inexpensive catalyst. To the best of our knowledge, quaternary ammonium salts, more specifically TEABr, have notbeen used as catalysts for the synthesis of pyrano[2,3-c]pyrazoles, and we decided to investigate the application of TEABr as a catalyst for the synthesis of a series of pyrazole-fused pyran derivatives via multi-component reactions |
| Description: | Organic Preparations and Procedures International, 45:429–436, 2013 |
| URI: | http://dyuthi.cusat.ac.in/purl/4146 |
| Files | Size |
|---|---|
| An Efficient Mu ... razole-5-carbonitriles.pdf | (136.6Kb) |
| Abstract: | A series of novel naphthyridine derivatives 3 and 4 was prepared from substituted pyridine 2 and ketones using ZnCl2 as catalyst under microwave irradiation conditions. All the compounds were evaluated for AChE inhibitory activity and promising compounds 3d, 3e, 4b, and 4g was identified. Representative compounds 3d and 3e were found to show insignificant THLE-2 liver cell viability/toxicity. The binding mode between X-ray crystal structure of human AChE and compounds was studied using molecular docking method and fitness scores were found to be in good correlation with the activity data. |
| Description: | Med Chem Res (2012) 21:1785–1795 DOI 10.1007/s00044-011-9695-0 |
| URI: | http://dyuthi.cusat.ac.in/purl/4162 |
| Files | Size |
|---|---|
| A facile and si ... ivity, and molecular m.pdf | (1.024Mb) |
| Abstract: | A simple and facile strategy for the synthesis of highly substituted imidazoles has been developed by multi-component condensation of 1,2-diketone, aldehyde, amine, and ammonium acetate in presence of tetrabutyl ammonium bromide as catalyst |
| Description: | Res Chem Intermed (2012) 38:359–365 DOI 10.1007/s11164-011-0352-5 |
| URI: | http://dyuthi.cusat.ac.in/purl/4137 |
| Files | Size |
|---|---|
| A facile strate ... iumbromide as catalyst.pdf | (308.6Kb) |
Now showing items 1-3 of 3
Dyuthi Digital Repository Copyright © 2007-2011 Cochin University of Science and Technology. Items in Dyuthi are protected by copyright, with all rights reserved, unless otherwise indicated.