Microwave-assisted tandem reactions for the synthesis of 2-hydrazolyl-4-thiazolidinones (original) (raw)
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Proceedings
We present here a new proposal for the “one pot” generation of new 4-thiazolidinones (9a–e) through a multicomponent reaction under microwave irradiation conditions, using aromatic and heteroaromatic amines (8a–e), absolute ethanol as a “green” solvent and modifying the aldehyde group in the glycosidic residue, synthesized from D-mannitol. The study is focused in the variation of the irradiation times and the concentration of thioglycolic acid in order to study the possibility of controlling the structure and/or stereochemistry of the products formed in the reaction. Thiazolidinones 9a–d were obtained with a 69–82% The generation of the corresponding reaction products were monitored by TLC and CG-MS, taking reaction aliquots. The conditions reaction proved to be chemoselective depending on the excess of acid and irradiation times.
Proceedings of The 18th International Electronic Conference on Synthetic Organic Chemistry, 2014
We present here the study of selective synthesis of 1,3-thiazolidin-4-ones via microwave-assisted multi-component reaction under solvent-free conditions. Although, theoretically two different products are possible (benzothiazepinones 4 and thiazolidinones 5), the reaction gave only two diasteroisomers of 1,3-thiazolidin-4-ones (48-97%) in the threecomponent reaction between 2,3 : 4,5-di-O-isopropiliden-β-D-arabino-hexos-2-ulo-2,6piranosa 1, different heteroaromatics anilines 3 and mercaptoacetic acid 2 as can be seen in the scheme of Figure 1. The synthesized compounds were characterized by IR, 1 H-, 13 C, DEPT and HSQC-RMN. The stereochemistry of both the diasteroisomers was elucidated with the help of NOE experiments.
Journal of Heterocyclic Chemistry, 2014
Hantzsch cyclization of thiosemicarbazone intermediates is a very popular approach to the synthesis of substituted thiazoles. We developed a convenient microwave and ultrasound-assisted method both for the synthesis of 1-(alkyliden/cycloalkyliden/aryliden)thiosemicarbazone intermediates and their cyclization into (4,5-substituted-thiazol-2-yl)hydrazines. The search for optimal reaction conditions included the use of different catalysts (Lewis acids and resins) and solvents at discrete temperatures, pressures, and irradiation powers. Comparing yields, reaction times, and efforts proved that microwave and ultrasound-assisted techniques outmatch conventional heating and have a remarkable influence on the synthesis.
Letters in Drug Design & Discovery, 2011
A novel synthetic method has been developed with palladium-catalyzed Buchwald-Hartwig-type reaction for the synthesis of N-tert-butyl-3-{[2-(arylamino)pyrimidin-4-yl]amino} benzenesulfonamide 5 by the treatment of N-tert-butyl-3-[(2-chloropyrimidin-4-yl)amino] benzenesulfonamide 4 with different aromatic amines in the presence of Cs 2 CO 3 and in DMF under microwave conditions. All the eight compounds 5a-h were evaluated for their antibacterial, antifungal, and cytotoxic activities. Among the title compounds, 5c and 5d showed potent activity towards both gram-positive and gram-negative bacteria. Compounds 5c and 5d displayed good antifungal activity, and the compounds 5c, 5d, and 5f exhibited significant cytotoxicity activity.
Orbital - The Electronic Journal of Chemistry, 2016
Several substituted 4-thiazolidinone derivatives 2a-q have been synthesized from halogenohydroxy substituted Schiff bases 1a-q under microwave irradiation technique. The reactions were carried out using ethanol: 2-methoxyethanol mixture as efficient reaction solvent system to afford high yield of product. The structures of newly synthesized compounds have been established on the basis of elemental analysis, IR, 1 H & 13 C NMR and mass spectral data. Further, all newly synthesized compounds were screened for their in vitro antimicrobial activity. The antifungal and antibacterial effects of the tested compounds are due to their molecular structure and substituent present.