Design, Synthesis and Biological Evaluation of Novel N-Arylpiperazines Containing a 4,5-Dihydrothiazole Ring

Arylpiperazines represent one of the most important classes of 5-HT(1A)R ligands and have attracted considerable interests for their versatile properties in chemistry and pharmacology, leading to the research of new derivatives that has been focused on the modification of one or more portions of such pharmacophore. An efficient protocol for the synthesis of novel thiazolinylphenyl-piperazines (2a–c) and the corresponding acetylated derivatives was used (3a–c). The new compounds were tested for their functional activity and affinity at 5-HT(1A) receptors, showing an interesting affinity profile with a Ki value of 412 nM for compound 2b. The cytotoxic activity of novel thiazolinylphenyl-piperazines (2a–c) and corresponding N-acetyl derivatives (3a–c) against human prostate and breast cancer cell lines (LNCAP, DU-145 and PC-3, MCF-7, SKBR-3 and MDA-MB231) was investigated according to the procedure described in the literature. The reported data showed a cytotoxic effect for 2a–c and 3a–c compounds (IC(50) values ranging from 15 µM to 73 µM) on the investigated cancer cell lines, with no effect on noncancer cells. Future studies will be aimed to investigate the mechanism of action and therapeutic prospects of these new scaffolds.