3,5-Dimethyl-1-thiocarbamoylpyrazole and its Pd(II) complexes: synthesis, spectral studies and antitumor activity

Complexes of the type [PdX2(tdmPz)] {X=Cl-(1), Br-(2); I-(3); SCN-(4); tdmPz=1-thiocarbamoyl-3,5-dimethylpyrazole} have been synthesized and characterized. Compound 1 was formed from the reaction between [PdCl2(CH3CN)2] and 1-thiocarbamoyl-3,5-dimethylpyrazole. Complexes 2, 3 and 4 were obtained by metathesis of the chloro groups from 1 by bromide, iodide and thiocyanate ions, respectively. All the compounds and cisplatin have been tested in vitro by MTT assay for their cytotoxicity against three murine cancer cell lines: mammary adenocarcinoma (LM3 and LMM3) and lung adenocarcinoma (LP07) as well towards normal murine peritoneal exudate cells (PEC). Promising cytotoxic effect against LM3 has been found for 3 showing IC50 equal to 24.5 microM which is comparable to the value obtained for cisplatin (30.3 microM).