Preparation of some new pyrazolo[1,5-a]pyrimidines and evaluation of their antioxidant, antibacterial (MIC and ZOI) activities, and cytotoxic effect on MCF-7 cell line

In this work, some novel pyrazolo[1,5-a]pyrimidine derivatives were synthesized and characterized by 1 H and 13 C NMR, FT-IR and mass spectra data. These compounds exhibited good to high antioxidant activities (DPPH radical scavenging capabilities). Among them, compound 3h showed the highest antioxidant activity (IC 50 = 15.34 μM) compared to ascorbic acid (IC 50 = 13.53 μM) as a standard compound. Their antibacterial activities were investigated against two Gram-positive bacteria ( B. subtilis , and S. aureus) and two Gram-negative bacteria ( P. aeruginosa , and E. coli ). The results showed that compound 3i has the best antibacterial activity against Gram-positive B. subtilis (ZOI= 23.0±1.4 mm, MIC= 312 μM). Also, the cytotoxicity of these compounds was assessed against breast cancer cell line (MCF-7), which compound 3f displayed the most cytotoxicity (IC 50 = 223.9 μM), in contrast with Lapatinib (IC 50 = 136.6 μM) as a known drug.