Microwave-assisted tandem reactions for the synthesis of 2-hydrazolyl-4-thiazolidinones

• Published in: Tetrahedron letters Vol. 50; no. 8; pp. 901 - 904
• Main Authors: Saiz, Cecilia, Pizzo, Chiara, Manta, Eduardo, Wipf, Peter, Mahler, S. Graciela
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 25.02.2009; Elsevier
• Subjects: 2-Hydrazolyl-4-thiazolidinones; 2-Hydrazolyl-5,5-diphenyl-4-thiazolidinones; Chemistry; Chemistry, Organic; Microwave; Physical Sciences; Science & Technology; Tandem reactions; Microwave; 2-Hydrazolyl-5,5-diphenyl-4-thiazolidinones; 2-Hydrazolyl-4-thiazolidinones; Tandem reactions; POTENT; CHELATORS; AGENTS
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2008.12.020

Microwave-assisted tandem synthesis of 2-hydrazolyl-4- thiazolidinones 5 is described starting from commercially available aldehydes, maleic acid, and thiosemicarbazide. The novel 5,5-diphenyl-4-thiazolidinone 7 was obtained by reaction of thiosemicarbazone with benzil in basic media through a benzilic rearrangement. A tandem method for the synthesis of 2-hydrazolyl-4-thiazolidinones ( 5) from commercially available materials in a 3-component reaction has been developed. The reaction connects aldehydes, thiosemicarbazides, and maleic anhydride, effectively assisted by microwave irradiation. The synthesis of a new type of compound, 2-hydrazolyl-5,5-diphenyl-4-thiazolidinone ( 7), obtained by treatment of thiosemicarbazone with benzil in basic media is also reported. HOMO/LUMO energies, orbital coefficients, and charge distribution were used to explain the proposed reaction mechanism.