Of 4-thiazolidinones

The rapid synthesis of 4-thiazolidinones by the MCR of an amine, aldehyde and mercaptoacetic acid has been developed under microwave-assisted conditions [73-75]. Irradiation of the three components in ethanol at 120 °C in the presence of molecular sieves [73] or in toluene at reflux under atmospheric conditions [74] in a single-mode microwave synthesizer gave the... 

The intramolecular cyclization reaction of 4-thiazolidinones 290, promoted by iodine in the presence of potassium iodide (or by reaction with methyl iodide in methanol), gives thiazolo[4,3-A [l,3,4]oxadiazoles 110 and 341 (Equation 63) (Table 54) <2001IJC(B)440, 1996JCR(S)388>. 

Ault-Justus, S. E., Hodges, J. C. Wilson, M. W. Generation of a Library of 4-Thiazolidinones Utilizing Polymer Supported Quench (PSQ) Reagent Methodology, Biotechnol. Bioeng. 1998, 61, 17. 

Holmes CP, Chinn JP, Look GC, Gordon EM, Gallop MA, Strategies for combinatorial organic synthesis solution and polymer-supported synthesis of 4-thiazolidinones and 4-metathiazanones derived from amino acids, J. Org. Chem., 60 7328-7333, 1995. 

The chemistry of 4-thiazolidinones (1) was reviewed in depth by Brown in 1962.1 Since then, largely due to the wide variety of physiological activity demonstrated by this class of compounds, several thousand papers2 on the chemistry of 4-thiazolidinone derivatives, exclusive of rhodanine derivatives, have been published. This review will consider only the important literature highlights of 1, 2,4-thiazolidinediones (2), 2-imino-4-thiazolidinones (3), and 4-oxo-2-thiazolin-2-ylhydrazones (4). Neither rhodanine (5) nor the extensive patent and obscure literature references dealing with 4-thiazolidinones will be considered in any detail within this review. 

The most widely used procedures for the preparation of 4-thiazolidinones describe the formation of the 3,4-bond via cyclization of an appropriately substituted acyclic compound which had been generally prepared from either thiourea or thioglycolic (mercaptoacetic) acid derivatives. Formation of... 

The structures of isomeric 2-methylenethiazolidin-4-ones have been ascertained by NMR analysis.69 Recently, several papers on 13C-NMR spectra of 4-thiazolidinones have been reported.184... 

A carbodiimide (DCC) mediated synthesis of 4-thiazolidinones 547 using amines, aldehydes and mercaptoacetic acid affords yields of 80-95... 

Recently, Holmes et al. reported the solution and polymer-supported synthesis of 4-thiazolidinones and 4-metathiaznones derived from amino acids (Scheme 7) [29]. A three-component condensation of an amino ester or resin-bound amino acid (glycine, alanine, /1-alanine, phenylalanine, and valine). 

A method involving the facile addition of mercaptoacetic acid across the double bond of an azomethine for the one-step preparation of 4-thiazolidinones has been used in the synthesis of thiazolo[2,3-c][l,4]thiazine-3(2//)-one. Thus, 2f/-3,4-dihydro-1,4-thiazines (138) react with alkyl mercaptoacetic acid at 100°C under nitrogen to give thiazolo[2,3-c][l,4]thiazin-3(2//)-ones (139) Similarly, 7/f-hexahydro-l,4-benzothia-zine[138, RR = (CH2)4] condenses with mercaptoacetic acid to yield 139 [RR = (CH2)4, R = R = H] (64M1335) (Scheme 30). 

Thione adds to the unsaturated carbon—carbon linkage of maleic anhydride probably by a Michael-type reaction, subsequent cyclization results in the synthesis of 4-thiazolidinone derivatives. The reaction of thi-... 

Syntheses of different heterocyclic systems in which the 2,3- and 2,5-positions of 4-thiazolidinones (1) are attached to different rings have also come from Potts laboratory. 

---