Synthesis and antitumor activity of some new pyrazolo[1,5-a]pyrimidines

New series of pyrazolo[1,5-a]pyrimidine derivatives 7a–i, 11a–c and Schiff bases 13a–c were synthesized and screened for their in vitro antitumor activity against three human carcinoma cell lines, namely colorectal carcinoma (HCT116), prostate adenocarcinoma (PC-3) and liver carcinoma (HepG-2) using MTT cytotoxicity assay at 100 μg/mL. Some of the tested compounds displayed good anticancer activities against HCT-116 and PC-3 cells. Whereas, compounds 7d and 11a showed better antitumor activity than the rest of the compounds against both cell lines. A structure-activity relationship (SAR) has been discussed and structures of the newly synthesized compounds were confirmed by different spectral data (MS, IR,1H NMR and13C NMR) and elemental analysis.