silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

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...

Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-halo-1H-pyrazoles are found to be important intermediates that can easily be converted into 1,2,5-triaryl-substituted pyrazoles via Pd-catalyz...

Objective: Pyrazoles have wide application in medicinal chemistry because of diverse pharmacological activities. As a part of our ongoing research to identify potential inhibitors of cysteine proteases, these observations were guiding initiatives in the present work for the synthesis of some pyrazoles with a desire to see their inhibitory effect on endogenous proteolysis. Methods: We have synth...

Zolo1, 2-apyrazole-1-one or its salts are used as a hair dye with red. In addition, pyrazolo3, 4-cpyrazoles are useful for the treatment of.novel glucosyl pyrazole derivatives starting from D-glucose. Pyrazoles are chemical compounds of synthetic origin that.Pyrazoles: Synthetic Strategies and Their Pharmaceutical. Abstract: Pyrazoles are an important class of five membered heterocyclic compoun...

The Au atom in the C2-symmetric pincer-type title complex, [AuCl(C(19)H(23)N(5))], is in the +3 oxidation state. The ligand is composed of one pyridine unit and two n-butyl-substituted pyrazoles (pyrz). Both pyrazoles are deprotonated, thus forming a neutral compound. To the best of our knowledge, this is the first Au(III)-bis-pyrazolate complex. According to the special geometry in the N,N',N'...

Various tetrasubstituted pyrroles/pyrazoles have been prepared from nitro-substituted 1,3-enynes with aromatic amines/hydrazines via a copper-catalyzed cascade aza-Michael addition, cyclization and aromatization at room temperature. This protocol is also effective for the synthesis of tetrasubstituted pyrazoles in high yields.

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.