Browsing by Author "Sun, CM"

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Microwave-assisted benzimidazole cyclization by bismuth chloride
(2005-05-17)
Su, YS
;
Sun, CM
;
應用化學系
;
Department of Applied Chemistry
We have developed a multi-step, microwave-assisted method for the bismuth chloride catalyzed synthesis of 1,2-disubstituted benzimidazoles. Biologically interesting benzimidazoles were readily assembled using a SNAr reaction, reduction, and finally a bismuth(III)-mediated cyclization under microwave irradiation. The desired products were then liberated from the soluble matrix in excellent yield and purity after cleavage. Each step of the synthetic sequence was performed under microwave conditions.
One pot synthesis of oxygenated tri-heterocycles as anti-microbial agents
(2005-11-01)
Khan, IA
;
Kulkarni, MV
;
Sun, CM
;
應用化學系
;
Department of Applied Chemistry
A one pot synthesis of an array of angularly linked tri-heterocycles with coumarin, benzofuran and furan rings is described. This high yielding synthesis is achieved by the reaction of various 4-bromomethylcoumarins with furyl o-hydroxyphenyl ketones involving benzylic nucleophilic displacement and intramolecular aldolization. All the compounds have been tested in vitro for their anti-microbial activity against Micrococcus aureus, Pseudomonas chinchori, Asperigillus fumigatus and Penicillium wortmanni at 100, 50, and 25 mu g ml(-1) concentrations. Chloro groups in the benzofuran ring enhanced the activity. (c) 2005 Elsevier SAS. All rights reserved.
Parallel synthesis of amino bis-benzimidazoles by multistep microwave irradiation
(2006-04-10)
Wu, CH
;
Sun, CM
;
應用化學系
;
Department of Applied Chemistry
A multistep liquid phase synthesis of specifically functionalized bis-benzimidazoles is presented by the application of single-mode microwave irradiation technique. The sustained solubilizing power and stability of the PEG-ester derived from the commercially available 4-fluoro-3-nitrobenzoic acid has been successfully carried through 10 steps involving iPSO-SNAr reaction, neutral reduction and acid cyclization. All the steps in this synthetic sequence were assisted by microwave (MW) irradiation. The polymer support was cleaved to release the final head to tail bisbenzimidazoles in an efficient process. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis and biological evaluation of novel angularly fused polycyclic coumarins
(2005-08-01)
Khan, IA
;
Kulkarni, MV
;
Gopal, M
;
Shahabuddin, MS
;
Sun, CM
In a three-step sequence, an array of angularly fused polycyclic heterocycles with coumarin, benzofuran and pyridine rings were synthesized from 4-bromomethylcoumarins and salicylonitrile. All the final compounds were fully characterized and screened for anti-microbial, anti-inflammatory and analgesic activities. Several compounds exhibited promising inflammation inhibiting and anti-microbial properties. (c) 2005 Elsevier Ltd. All rights reserved.
Traceless and stereoselective synthesis of tetrahydro-beta-carbolinethiohydantoins by microwave irradiation
(2006-03-01)
Chang, WJ
;
Kulkarni, MV
;
Sun, CM
;
應用化學系
;
Department of Applied Chemistry