Synthesis, structure elucidation and biological evaluation of substitued thiourea derivates

During recent years there have been intense investigations on the different classes of thiourea compounds, many of which known to possess interesting biological properties such as antimicrobial, antibacterial, analgesic, antiflammatory, anticancer, antifungal, antituberculosis, anti-HIV, anticonvulsant and antihypertensive activities.In this search to be composed of three parts, by using general synthesis methods 21 original and 2 registered in literature compounds were synthesized. In the first part of study, 5-(4-nitrobenzilydene)-2-thioxo-1,3-thiazolidine-4-one [I] was synthesized by the condensation rhodanine with 4-nitrobenzaldehyde according to the literature. After the reduction of nitro group of compound [II] to corresponding amines, thiourea derivatives [IIIa-h] were obtained by the addition to substituted isothiocyanates. In the second part of study, 3-(2-aminoethyl)-2-thioxo-1,3-thiazolidine-4-on [IV] was synthesized by reactions rhodanine and 2-chloroethylamine hydrochloride according the literature, then substitue isothiocyanates were added to the biologically active amines due to obtain thiourea derivates [Va-d]. The last part of study, a series of thiourea derivates were obtained by the condensations of 2-amino-5-chlorobenzoxazole, 2-amino-5-chloropyrimidine and 3-amino-5-(4-flurophenyl) isoxazole with different isothiocyanates [VIa-c, VIIa-b, VIIIa-c]. The purity were controlled by TLC and the chemical structures of the synthesized compounds were elucidated using IR, 1H-NMR, mass spectroscopy and elemental analysis.