By the reaction of (4-furan-2-yl-thiazol-2-yl)- 3a and (4-thiophen-2-yl-thiazol-2-yl)- 3b acetonitriles with furfural 4 and 5-arylfurfyrals 5a-g 3-furan-2-yl-2-(4-furan/thiophen-2-ylthiazol-2-yl)acrylonitrile derivatives 6a-i were obtained. Anticancer activity screening was carried out within the framework of Developmental Therapeutic Program of the National Cancer Institute's (DTP, NCI, Bethesda, Maryland, USA). It was found out that (2E)-3-(2-furyl)-2-[4-(2-furyl)-1,3-thiazol-2-yl]acrylonitrile (6a) and 2-(4-thiophen-2-yl-thiazol-2-yl)-acrylonitriles 6h,i possessed low activity and 2-(4-furan-2-yl-thiazol-2-yl)acrylonitrile derivatives 6b-g showed moderate action. Compounds 6b-g were sensitive to cell lines of MDA-MB-468 and T-47D Breast Cancer. In this case cytotoxic effect was observed with a range of GP = -38.24 –1.28%.

A series of novel 1,3,4-thia(oxa)diazole substituted 2-(2,4-dioxothiazolidine-5-ylidene)-acetamides 3a-c, 4 and 5a-k have been synthesized following the acylation reaction of 2-amino-5-aryl-1,3,4-oxadiazoles, 5-amino-1,3,4-thiadiazole-2-thiol and it’s S-alkylated derivatives with 2-(2,4-dioxothiazolidine-5-ylidene)acetyl chloride in dioxane medium. The functionalization of compounds 3b, 3c, 5d and 5e was carried out on their N3 position under N-alkylation conditions with N-aryl-2-chloroacetamides in DMF/ethanol medium yielded the corresponding 2,4-dioxothiazolidine-3,5-diacetic acid diamides 6a-e and 7a-b. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. The antioxidant activity evaluation in vitro of the synthesized compounds was performed by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the highly active compound 4, namely 2-(2,4-dioxothiazolidin-5-ylidene)-N-(5-mercapto-[1,3,4]thiadiazol-2-yl)acetamide was found to be the most efficient candidate among all compounds with a radical scavenging ability of 88.9%, which was comparable that for ascorbic acid (92.7%). The experimentally calculated IC50 value of 43.1 μM for compound 4 was lower than for ascorbic acid (50.5 μM).