The synthesis and the anticonvulsant activity screening of new 5-substituted 2-imino-4-thiazolidinone derivatives

Abstract

Aim. To synthesize 5-ene-4-thiazolidinones containing heterocyclic rings in the molecule as potential anticonvulsants, and screen their anticonvulsant activity on a model of pentylenetetrazole (PTZ) seizures.Results and discussion. A straightforward and convenient synthesis of novel 5-ene-derivatives of thiazol/oxazole-bearing 4-thiazolidinones as possible anticonvulsant agents was performed. Compounds were characterized using methods of spectral analysis (1H NMR and LC-MS). 5-Chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde underwent the aminolysis on a chlorine atom by a molecule of monoethanolamine (MEA) in the Knoevenagel reaction with thiazole/oxazole-bearing 4-thiazolidinones. The preliminary screening of the anticonvulsant activity was performed for the compounds synthesized on the model of PTZ-induced seizures, and active derivatives were identified.Experimental part. Commercially available 2-aminothiazole and 5-methylisoxazol-3-amine were used as starting compounds for the synthesis of 2-chloro-N-(hetaryl)acetamides. The latter were transformed into thiazole/oxazole-bearing 4-thiazolidinones by the treatment with ammonium isothiocyanate. Modification at C5 position of the heterocycles synthesized was performed by the Knoevenagel reaction with aromatic/heteroaromatic aldehydes and MEA as a catalyst (either equimolar or 0.1 mol% amount) in the ethanol medium. The structure of novel derivatives was confirmed by 1H NMR and LC-MS spectra. The anticonvulsant activity of all derivatives synthesized was studied in vivo on the model of PTZ-induced seizures. Latency of the seizures, the number of clonic-tonic seizures in one mouse, the percent of animals with clonic and tonic seizures, the duration of the seizure period, and the lifetime of the animals before death were evaluated and calculated.Conclusions. The results obtained are promising for further design of potential anticonvulsants among oxazole-bearing 4-thiazolidones with the possible mechanism of the anticonvulsant action through the GABA-ergic impact and inhibition of the prostaglandin and leukotriene synthesis.