Synthesis and antiproliferative evaluation of new aryl substituted pyrido[3′,2′:5,6]thiopyrano[4,3-c]pyrazoles

The preparation and the cytotoxic properties of new derivatives of the planar pyrido[3',2':5,6]thiopyrano[4,3-c]pyrazole system, carrying an arylic side group in the I or 2 positions, are described. The novel substituted derivatives were obtained by reaction of suitable arylhydrazines with the appropriate key intermediate 3-hydroxy methylene-2,3 -dihydrothiopyrano [2,3-b] pyridin-4(4H)-ones. Moreover the preparation was reported of the 2-carboxamidophenyl derivatives, which was accomplished from the previously obtained pyrido[3',2':5,6]thiopyrano[4,3-c]pyrazole nucleus, by reaction with phenylisocyanate. All the new compounds were evaluated for their antiproliferative ability, by an in vitro assay on human tumor cell lines (HL-60 and HeLa).