The reaction of 5-amino-3-(4-methoxyphenylamino)-N -aryl-1 H -pyrazole-4-carboxamides 1a-c with ethyl acetoacetate 2 and 2-(4-fluorobenzylidene)malononitrile 6 yielded pyrazolo[1,5-a ]pyrimidines 5a-c and 9a-c, respectively. On the other hand, Schiff bases 11a-f were obtained upon treatment of carboxamides 1a-c with some selected aldehydes 10a and b. The newly synthesized compounds were characterized and confirmed by analytical and spectroscopic data (IR, MS, 1 H NMR, and 13 C NMR). Pyrazolo[1,5-a ]pyrimidines 5a-c and 9a-c and Schiff bases 11b-f were investigated for their cytotoxicity against four human cancer cell lines (colon HCT116, lung A549, breast MCF-7, and liver HepG2) according to SRB assay and the structure-activity relationship was discussed.

Complexes of the type [ML′L(OH)(H 2 O)], where M = Ni(II), Co(II) or Mn(II), L′ = isatin and HL = 3-(2-phenylhydrazono)acetylacetone, 3-(2-(4--chlorophenyl)hydrazono)acetylacetone or 3-(2-(4-bromophenyl)hydrazono)-acetylacetone, were synthesized by equimolar reaction of a metal(II) chloride with isatin and a 3-(2-arylhydrazono)acetylacetone. The resulting complexes were characterized by elemental analyses, molar conductivity, spectral data (IR and mass spectrometry) and magnetic moments. Furthermore, the ligands and their metal complexes were screened for their cytotoxicity against different human cancer cell lines using the sulforhodamine B (SRB) assay. The results showed that most of the mixed ligand metal complexes have high cytotoxicity in comparison with the reference drugs used.

Due to the importance of biological activities of 1,2,4-triazine derivatives, in this manuscript, ten of newly synthesized compounds containing 1,2,4-triazine moiety were prepared. Anticancer and antimicrobial activities of some selected synthesized compounds were screened. Chalcone derivatives 6, 7 were synthesized via reaction of Mannich base 2 in acetic acid and fused sodium acetate with formyl khellin 5 or vanillin. Treatment of chalcone derivatives 6, 7 toward hydrazine hydrate, phenyl hydrazine, hydroxylamine hydrochloride or malononitrile, respectively, led to give pyrazoline 8, 9, 10, 11, oxazole 12, 13 and pyridine 14, 15 derivatives, respectively. The structures of the isolated products were established by elementary analysis and spectral data studies. Compounds 1, 5, 6, 8, 10, 12 and 14 were tested against different human cancer cell lines, and cytotoxicity in vitro and most of the synthesized compounds were proved to have high activities against cytotoxic test. Then, the compounds 1, 5, 6, 8, 10, 12 and 14 were tested against cancer in vivo, and the result was established. Also, antimicrobial activity of compounds 1, 5, 6, 8, 10, 12 and 14 was screened in vitro against a panel of gram-positive and gram-negative bacterial pathogens and fungi. The results indicated that compound 5 showed higher antimicrobial activity than compounds 1, 6, 8, 10, 12 and 14, and compound 5 exhibited a wide range of antimicrobial activities against gram-positive and gramnegative bacteria and fungi, greater than well-known antibacterial and antifungal agents with minimal inhibitory concentration ranged between 6.25 and 25 lg.