[en] Convenient synthetic method for 4-arylethylpyrazoles and 4-styrylpyrazoles was developed using α-alkenyl-α,β-enones readily accessed from the Morita-Baylis-Hillman reaction. For the synthesis of 4-arylethyl-pyrazole, the reactions with arylhydrazines needed to be carried out in o-dichlorobenzene under N₂ balloon atmosphere. On the other hand, 4-styrylpyrazoles required the reactions in ethanol under O₂ balloon atmosphere

[en] DFT calculations have been carried out on 6,6-dimethyl-7-nitroso-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine concerning energies, absolute shieldings (GIAO) and moleculargraphs (AIM) to determine the molecular structureof the compound (tautomerism and conformation of thenitroso group). (Author)

[en] An introduction to the uses and importance of pyrazole-5-one and -2- pyrazoline derivatives, it also contains a concise review of methods of determination for these derivatives, as well, basis of amplification reactions, spectrophotometer, diazotization and polarography. The second chapter deals with determination of some pyrazole-5- one and -2-pyrazoline derivatives by titrimetric method in combination with amplification procedures.(40 tabs., 8 figs., 103 refs.)

[en] Novel rhodanine–pyrazole conjugates (6a–i) and their simple rhodanine analogues (8a–e) were prepared and comparatively screened for their antidiabetic activities against enzymatic targets, α-glucosidase and α-amylase. As expected, the molecular hybrids exhibited significantly greater inhibitory activity against α-glucosidase (IC₅₀ = 2.259 × 10⁻⁶–1.160 × 10⁻⁴ mol/L), relative to their simple rhodanine counterparts (IC₅₀ = 3.056 × 10⁻⁴–9.494 × 10⁻⁴ mol/L). Amongst the screened derivatives compounds 6a and 6f displayed a 3-fold and 42-fold greater potency against α-glucosidase (IC₅₀ = 2.854 × 10⁻⁵ and 2.259 × 10⁻⁶mol/L, respectively) compared to the standard drug, acarbose. The designed molecular conjugates displayed an improved binding affinity toward α-glucosidase than α-amylase. Compound 6d was identified as the most potent inhibitor of α-amylase (IC₅₀ = 6.377 × 10⁻⁵ mol/L) with a 1.5-fold greater inhibitory activity than acarbose. Structural assessment of the molecules revealed that electron withdrawing (Cl) and electron donating (OCH₃) groups at the ortho-position played a significant role in the inhibitory activity. Molecular docking studies of the molecular conjugates and simple rhodanine analogues in the active site of α-glucosidase were performed to describe and highlight the putative binding interactions attributing to the selective inhibition. The identification of these novel rhodanine–pyrazole molecular hybrids forms part of a potential treatment in the management of diabetes.

[en] Some N-acetyl pyrazoles including 1-(3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-¹H-pyrazole-1-yl) ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones like substituted styryl 3,4-dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: H₂SO₄ catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75%. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data

[en] A practical and efficient one-pot synthesis of 1,3,5-trisubstituted pyrazoles from α,β-enones and arylhydrazine hydrochlorides has been developed. The pyrazoles were formed via a tandem formation of the corresponding pyrazolines and an acid-catalyzed aerobic oxidation process

[en] The reaction of 1,3,5-triketones and arylhydrazines provided indolylpyrazole derivatives in a one-pot reaction in good to moderate yields. Both the pyrazole and indole rings were constructed simultaneously with phenylhydrazine, RCOCH₂CO- moiety for the pyrazole and the remaining -CH₂COR part for the indole ring

[en] The interaction of N1-phenyl-, N1-(2-benzyl-6-methylpyrimidin-4-yl)- and N1-(4,6-dimethylpyrimidin-2-yl)-substituted 3-methyl-5-aminopyrazoles with ethoxymethylidene derivatives of acetylacetone, as well as ethyl ester of acetoacetic and cyanoacetic acids has been studied. As a result of the reactions, non-cyclic products were isolated - derivatives of conjugated α, β-unsaturated carbonyl compounds - chalcones. The alkylation of the synthesized substituted pyrazolylchalcone with methyl iodide has been studied

[en] The semi-linear pyrazole containing polymeric structures have been synthesized by three different methods to produce 4-(4-(phenyldiazenyl)-1H-pyrazole-3,5-diyl)oligomer, copolymer and homopolymer analogous with molecular weight up to 24000 g mol^-1 . Thermogravimetric analysis showed that the copolymer and homopolymer analogous have high thermal stability than the oligomer. The photoluminescence behaviour and sensing application of the new compounds were analysed by UV–visible spectroscopy and fluorescence spectroscopy. The copolymer analogue was found to show high sensitivity to acetate anion. (author)

[en] The syntheses, properties and applications of dinitropyrazoles are systematically reviewed.