An efficient copper-mediated three-component reaction of 2,3-allenoates or 2-alkynoates, amines, and nitriles affording fully substituted pyrazoles with a very nice diversity has been developed. A tandem conjugate addition, 1,2-addition, and N-N bond formation mechanism has been proposed for this diverse synthesis of pyrazoles based on mechanistic studies.

Pyrazoles have been studied for over a century as an important class of heterocyclic compounds and continue to attract considerable interest due to the broad range of biological activities they possess. The incorporation of the essential structural features of pyrazoles with a ferrocene moiety could provide new derivatives with unexpected and/or enhanced biological activities since several ferr...

The inhibitive effect of compound (1-acetyl-4, 5-dihydro-5-Bromophenyl-3-(thiophen-2yl) pyrazoles) on mild steel in 1M H2SO4 and 1M HCl was investigated by weight loss, Potentiodynamic polarization and electro chemical impidence studies. The synthesized compound of 1-acetyl-4, 5-dihydro-5-Bromophenyl-3-(thiophen-2yl) pyrazoles was characterized by FTIR, H NMR, C NMR and mass. The purity of the ...

A synthesis of tetrasubstituted pyrazoles containing two, three or four pyridinyl substituents is described. Hence, the reaction of 1,3-dipyridinyl-1,3-propanediones with 2-hydrazinopyridine or phenylhydrazine, respectively, affords the corresponding 1,3,5-trisubstituted pyrazoles. Iodination at the 4-position of the pyrazole nucleus by treatment with I2/HIO3 gives the appropriate 4-iodopyrazol...

BACKGROUND Isoxazoles exhibit interesting biological activities, and the 1,3-dipolar cycloaddition(13DC) reactions play an important role in both mechanistic and synthetic organic chemistry. Pyrazoles and annulated pyrazoles exhibit some diverse biological activities. They are used as antipyretic, analgesic drugs, tranquilizing, and herbicidal agents. Pyrazoles are also used extensively as usef...

А para-chlorophenyl substituent was firstly obtained into the structure of pyridyl-substituted 4-nitrosopyrazole by cyclocondensation hydrazine hydrate with corresponding isonitroso-β-dicarbonyl compounds. The previously unknown 3(5)-(4-chlorophenyl)-5(3)-pyridine-(3(4))-yl-4-nitroso-1H-pyrazoles and 3(5)-alkyl(aryl)-5(3)-pyridine-(3(4))-yl-4-nitroso-1H-pyrazoles is proved studied in detail mod...

Ethyl diazoacetate (EDA), which is easily prepared from ethyl glycinate and NaNO2, reacts in situ with alkynes a water micelle environment without organic solvent to form pyrazoles. The reaction pH dependent, as the presence of protic catalysis (H2SO4 4 %, 3.5) mixture 3,5- 4,5-disubstituted pyrazoles was obtained, while, at 5.5, only 3,5-disubstituted isomer obtained. surfactant TPGS-750-M cru...

To develop compounds that are antagonists on ER , but not ER , we have added basic side-chains typically found in nonsteroidal antiestrogens to pyrazole compounds that bind with much higher affinity to ER than to ER . In this way we have developed basic side-chain pyrazoles (BSC-pyrazoles) that are high affinity, potent, selective antagonists on ER . These BSCpyrazoles are themselves inactive o...

A quantitative structure activity relationship (QSAR) study on tetrasubstituted pyrazoles as high affinity ligands for the estrogen receptor (both ERα and ERβ subtypes) have been performed using various combinations of hydrophobic (MlogP), steric (MR) and electronic (Xeq) descriptors. The regression analysis of the data has shown better results in multiparametric regressions upon introduction o...

Enantiomeric-enriched ferrocene-modified pyrazoles were synthesized via the reaction of the ferrocene alcohol, (S)-FcCH(OH)CH₃ (Fc = ferrocenyl), with various pyrazoles in acidic conditions at room temperature within several minutes. X-ray structural data for racemic (R,S)-1N-(3,5-dimethyl pyrazolyl)ethyl ferrocene (1) and its (S)-enantiomer (S)-1 were determined. A series of racemic pyrazolyla...