Facile Synthesis and Anticancer Evaluation of Novel 1-(Thiazol-2-yl)-3-(thiazol-5-yl)-5-(thiophen-2-yl) Pyrazolines

Some novel pyrazoline derivatives bearing thiazole and thiophene moieties have been efficiently synthesized and characterized. The synthetic approach involves condensation of 5-acetylthiazole 1 with 2-formyl thiophene 2 followed by heterocyclization of the produced chalcone 3 with hydrazine and thiosemicarbazide under different conditions to give selectively 1-substituted-3-(thiazol-5-yl)-5-(thiophen-2-yl)pyrazolines 4-6 and 8 in high yields. Heterocyclization of 1-thicarbomylpyrazoline 8 with 3-chloro-2,4-pentanedione, phenacyl bromide and hydrazonoyl bromides in boiling ethanol and TEA results in the respective 1-(thiazol-2-yl)-3-(thiazol-5-yl)-5-(thiophen-2-yl)pyrazolines 11, 12, and 14a-14f. Anticancer activity of the novel 1,3,5-trisubstituted pyrazolines has been evaluated, against breast (MCF-7), liver (HepG2), and colon (HCT-116) cancer cell lines, as well as epithelial (REP1) normal cell line. Among the synthesized pyrazolines, compounds 8, 14a, and 14f demonstrate the highest anticancer activity with IC50 values of 1.83, 5.47, and 11.43 mu M, respectively, and presenting no evidence of human toxicity.

Automated summary

Novel pyrazoline derivatives bearing thiazole and thiophene moieties were synthesized and evaluated for their anticancer activity. Compounds 8, 14a, and 14f exhibited the highest activity against various cancer cell lines.