Hydrazonyl bromides 2a,b reacted with active methylene compounds (dibenzoylmethane, acetylacetone, ethyl acetoacetate, phenacyl cyanide, acetoacetanilide, ethyl cyanoacetate, cyanoacetamide and malononitrile) to afford the corresponding 1,3,4,5- tetrasubstituted pyrazole derivatives 5-12a,b. Reaction of 12a,b with formamide, formic acid and triethyl orthoformate give the pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4- d]pyrimidin-4(3H)one and 5-ethoxymethylene-aminopyrazole-4-carbo-nitrile derivatives 13-15a,b, respectively. Compounds 15a,b reacted with benzhydrazide and hydrazine hydrate to afford pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine and [4-iminopyrazolo- [3,4-d]pyrimidin-5-yl]amine derivatives 16a,b and 17a,b. Reactions of compounds 17a,b with triethyl orthoformate and carbon disulfide give the corresponding pyrazolo[4,3-e]- [1,2,4]triazolo[1,5-c]pyrimidine derivatives 18a,b and 19a,b, respectively.

Twelve novel chalcone derivatives were prepared using the Claisen–Schmidt condensation reaction. The reaction of 4‐acetyl‐5‐furan/thiophene‐pyrazole derivatives 5 with the corresponding aldehydes 6 afforded the targeted chalcone derivatives 7a–l in good yields. The newly synthesized chalcones were fully characterized by spectrometric and elemental analyses. The in vitro anticancer activities of the novel compounds 7a–l were evaluated against four human cancer cell lines: HepG2 (human hepatocellular carcinoma), MCF7 (human Caucasian breast adenocarcinoma), A549 (lung carcinoma), and BJ1 (normal skin fibroblasts). Compound 7g emerged as the most promising compound, with IC₅₀ = 27.7 µg/ml against A549 cells compared to the reference drug doxorubicin (IC₅₀ = 28.3 µg/ml), and IC₅₀ = 26.6 µg/ml against HepG2 cells compared to the reference drug doxorubicin (IC₅₀ = 21.6 µg/ml). The gene expression and DNA damage values and the DNA fragmentation percentages for compound 7g were determined on the lung and liver cell lines. The expression levels of the AMY2A and FOXG1 genes increased significantly (p < 0.01) in the negative samples of lung cancer cells compared with treated cells. Also, the expression values of the PKM and PSPH genes improved significantly (p < 0.01) in the negative samples compared with treated samples of liver cancer cells. The DNA damage values increased significantly (p < 0.01) in treated lung cell line samples (7g) and the positive control. The results showed a significant decrease (p < 0.05) in DNA damage values in the negative samples of liver cancer cells compared to those treated with 7g. However, the DNA fragmentation values increased significantly (p < 0.01) in the treated lung and liver cell line samples compared with the negative control.

Several 1,3-diaryl-5-(cyano-, aminocarbonyl- and ethoxycarbonyl-)-2-pyrazoline, pyrrolo[3,4-c]pyrazole-4,6-dione and 1,3,4,5-tetraaryl-2-pyrazoline derivativeswere prepared by the reaction of nitrilimine with different dipolarophilic reagents. The newcompounds were characterized using IR, ¹H-NMR, ¹³C-NMR and mass spectra. Biologicalscreening of some compounds is reported.