Reaction of arylidenehydrazono-4-aryl-2,3-dihydrothiazole-5-carbonitriles with diethyl acetylenedicarboxylate. Synthesis of (Z)-ethyl 2-[((Z)-2-(E)-arylidenehydrazono)-4-oxo-thiazolidine-5-ylidene]acetates. NMR investigation

Arylidenemalononitriles as Versatile Synthons in Heterocyclic Synthesis

BACKGROUND

Arylidenemalononitriles are valuable synthons for the construction of a variety of novel complex heterocyclic motifs, fused heterocycle derivatives and spirocyclic compounds. They are versatile chemical intermediates and have increasing applications in industry, agriculture, medicine, biological science.

OBJECTIVE

The aim of this review is to highlight the preparation methods and reactions of arylidenemalononitriles in the synthesis of various heterocyclic compounds.

CONCLUSION

In this review, we have presented the application of arylidenemalononitriles to construct a variety of heterocycles. Various catalysts for the preparation of arylidnemalononitriles have been described.

In vitro evaluation of new 4-thiazolidinones on invasion and growth of Toxoplasma gondii

Treatments for toxoplasmosis such as pyrimethamine have shown numerous side effects. It has been reported that the likelihood of relapse associated with pyrimethamine-based therapy in patients with HIV and toxoplasmic encephalitis (TE) can have significant implications, even for patients who often develop new lesions in areas of the brain previously free of infection. This led us to research for new agents against Toxoplasma gondii. Recent findings have shown the potent biological activity of 4-thiazolidinones. We proposed to design and synthesize a new series of 2-hydrazono-4-thiazolidinones derivatives to evaluate the in vitro growth inhibition effect on T. gondii. The growth rates of T. gondii tachyzoites in Human Foreskin Fibroblast (HFF) cell culture were identified by two in vitro methodologies. The first one was by fluorescence in which green fluorescent RH parasites and cherry-red fluorescent ME49 parasites were used. The second one was a colorimetric methodology using β-Gal parasites of the RH strain constitutively expressing the enzyme beta-galactosidase. The 4-thiazolidinone derivatives 1B, 2B and 3B showed growth inhibition at the same level of Pyrimethamine. These compounds showed IC50 values of 1B (0.468-0.952 μM), 2B (0.204-0.349 μM) and 3B (0.661-1.015 μM) against T. gondii. As a measure of cytotoxicity the compounds showed a TD50 values of: 1B (60 μM), 2B (206 μM) and 3B (125 μM). The in vitro assays and molecular modeling results suggest that these compounds could act as possible inhibitors of the Calcium-Dependent Protein Kinase 1 of T. gondii. Further, our results support the fact that of combining appropriate detection technologies, combinatorial chemistry and computational biology is a good strategy for efficient drug discovery. These compounds merit in vivo analysis for anti-parasitic drug detection.

Facile synthesis of bis-thiosemicarbazone derivatives as key precursors for the preparation of functionalised bis-thiazoles

A new class of bis-thiosemicarbazones was designed and synthesised by the condensation of 2,6-diformylphenol derivatives and thiosemicarbazide using either ultrasound or conventional methods. Both thiosemicarbazone groups of these derivatives underwent a heterocyclisation process to give a series of novel bis-thiazole derivatives as major products. The structures of all the synthesised compounds were characterised by multinuclear NMR (1H and 13C), IR, HRMS and elemental analyses.