[Antiviral agents. 27. The aminomethinylation of 5-oxo-2-pyrazoline-3-carboxylic acid derivatives]

Discovery of Anticancer Agents from 2-Pyrazoline-Based Compounds

As nitrogen-containing five-membered heterocyclic structural units, the substituted pyrazole derivatives have a broad spectrum of pharmacological activities, especially 4,5-dihydro-1H-pyrazoles that also commonly known as 2-pyrazolines. Since 2010, considerable studies have been found that the 2-pyrazoline derivatives possess potent anticancer activities. In the present review, it covers the pyrazoline derivatives reported by literature from 2010 till date (2010-2019). This review aims to establish the relationship between the anticancer activities variation and different substituents introduced into a 2-pyrazoline core, which could provide important pharmacophore clues for the discovery of new anticancer agents containing 2-pyrazoline scaffold.

Synthesis and Characterization of Some New Bis-Pyrazolyl-Thiazoles Incorporating the Thiophene Moiety as Potent Anti-Tumor Agents

A new series of 1,4-bis(1-(5-(aryldiazenyl)thiazol-2-yl)-5-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-3-yl)benzenes 3a–i were synthesized via reaction of 5,5′-(1,4-phenylene)bis(3-(thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carbothioamide) (1) with hydrazonoyl halides 2a–i. In addition, reaction of 1 with ethyl chloroacetate afforded bis-thiazolone derivative 8 as the end product. Reaction of compound 8 with methyl glyoxalate gave bis-thiazolone derivative 10. The structures of the newly synthesized compounds were established on the basis of spectroscopic evidences and their alternative syntheses. All the synthesized compounds were evaluated for their anti-tumor activities against hepatocellular carcinoma (HepG2) cell lines, and the results revealed promising activities of compounds 3g, 5e, 3e, 10, 5f, 3i, and 3f with IC₅₀ equal 1.37 ± 0.15, 1.41 ± 0.17, 1.62 ± 0.20, 1.86 ± 0.20, 1.93 ± 0.08, 2.03 ± 0.25, and 2.09 ± 0.19 μM, respectively.

Microwave-assisted one-pot synthesis of pyrazolone derivatives under solvent-free conditions

An efficient one-pot method to generate structurally diverse and medicinally interesting pyrazolone derivatives in good to excellent yields of 51–98% under microwave irradiation and solvent-free conditions has been developed.

Synthesis, characterization and pharmacological properties of some 4-arylhydrazono-2-pyrazoline-5-one derivatives obtained from heterocyclic amines

The synthesis of a new series of 4-arylhydrazono-2-pyrazoline-5-ones 7-24 and 22a is described. Structures of the synthesized compounds were confirmed using UV, IR, 1H-NMR, 13C-NMR and EI-mass spectral data. These compounds were tested in vitro against one Gram-positive and two Gram-negative bacterial strains, two mycobacterial strains and a fungus, Candida albicans. Compound 22 was found to be more active against Staphylococcus aureus than the other compounds at a concentration of 15.6 microg/mL. Some related compounds were evaluated for anticonvulsant activity. Compound 11 showed 40% protection against pentylenetetrazole-induced seizures in albino Swiss mice. In vitro antituberculosis activity of 4-arylhydrazono-2-pyrazoline-5-ones 7-12, 14-24, 22a and coupling products 6a-f were tested on Mycobacterium tuberculosis H37Rv. Of these compounds, only 24, which exhibited > 90% inhibition in the primary screen at 12.5 microg/mL against this strain was re-examined for determination of its actual MIC. However, level II assay revealed that the MIC value was not less than 12.5 microg/mL. The same compound was also tested against Mycobacterium avium, which was observed not to be susceptible to 24.