Synthesis and in vitro anticancer activity of pyrazolo[1,5- a ]pyrimidines and pyrazolo[3,4- d ][1,2,3]triazines.

A novel series of pyrazolo[1,5-a]pyrimidines14a–jand pyrazolo[1,5-a]quinazolines18a, bwere synthesizedviacondensation of 5-amino-1H-pyrazoles10a, bwith 3-(dimethylamino)-1-aryl-prop-2-en-1-ones11a–eand 2-((dimethylamino)methylene)-5,5-dimethylcyclohexane-1,3-dione (15), respectively, in glacial acetic acid. Finally, treatment of10a, bwith sodium nitrite (NaNO2) afforded pyrazolo[3,4-d]triazines20a, b. Structures of compounds were confirmed by their spectral data. These compounds were screened for theirin vitrocytotoxic activities against human cancer cell lines (HepG-2 and MCF-7) using 3-[4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. The results reveal that, the compounds14band14hwere the most potent in comparison with doxorubicin. The structure–activity relationship was discussed. [ABSTRACT FROM PUBLISHER]