25142-45-4

Upstream product

• 122-78-1 phenylacetaldehyde 
• 222180-54-3 diethyl [2-phenyl-2-(2-tosylhydrazono)ethyl]phosphonate 
• 98-86-2 acetophenone 
• 1623809-04-0 C₁₇H₁₈N₂O₂S 
• 536-74-3 phenylacetylene 
• 13504-37-5 diethyl phenylacetylphosphonate 
• 173848-00-5 (1-Hydrazono-2-phenyl-ethyl)-phosphonic acid diethyl ester 
• 103-80-0 phenylacetyl chloride 
• 886-66-8 1,4-diphenyl-1,3-butadiyne 
• 591-50-4 iodobenzene 
• 10147-11-2 propargyl benzene 
• 3453-00-7 diethyl benzoylmethylphosphonate 
• 3442-15-7 1,4-diphenylbutane-1,3-dione 

Relevant academic research and scientific papers

Highly Efficient Cycloaddition Reaction of 1,3-Diynes with Sodium Azide: A New Way to 5-Substituted-4-acetylene-1H-1,2,3-triazoles

A cycloaddition reaction of a range of 1,3-diynes with sodium azide has been realized, which provided 5-substituted-4-acetylene-1H-1,2,3-triazoles in 75–99% yields. The chemical structures of the new compounds 3 are established by IR, NMR, Mass, and HRMS.

Synthesis of dihydropyrazoles via ligand-free Pd-catalyzed alkene aminoarylation of unsaturated hydrazones with diaryliodonium salts

A ligand-free, palladium-catalyzed aminoarylation reaction of the unactivated alkenes in β,γ-unsaturated hydrazones is described. This protocol enables efficient and simultaneous formation of C(sp3)-N and C(sp3)-C(sp2) bonds under mild conditions, providing a practical and general approach to various diversely substituted dihydropyrazoles in generally good yields, without the use of any stoichiometric external oxidant.

Diazophosphonates: Effective Surrogates for Diazoalkanes in Pyrazole Synthesis

Diazophosphonates, readily prepared from α-ketophosphonates by oxidation of the corresponding hydrazones in batch or in flow, are useful partners in 1,3-dipolar cycloaddition reactions to alkynes to give N-H pyrazoles, including the first intramolecular examples of such a process. The phosphoryl group imbues a number of desirable properties into the diazo 1,3-dipole. The electron-withdrawing nature of the phosphoryl stabilizes the diazo compound making it easier to handle, whilst the ability of the phosphoryl group to migrate readily in a [1,5]-sigmatropic rearrangement enables its transfer from C to N to aromatize the initial cycloadduct, and hence its facile removal from the final pyrazole product. Overall, the diazophosphonate acts as a surrogate for the much less stable diazoalkane in cycloadditions, with the phosphoryl group playing a vital, but traceless, role. The cycloaddition proceeds more readily with alkynes bearing electron-withdrawing groups, and is regiospecific with asymmetrical alkynes. The potential of diazophosphonates for use in bioorthogonal cycloadditions is demonstrated by their facile addition to strained alkynes.

Continuous-flow synthesis of 3,5-disubstituted pyrazoles: Via sequential alkyne homocoupling and Cope-type hydroamination

A flow chemistry-based approach is presented for the synthesis of 3,5-disubstituted pyrazoles via sequential copper-mediated alkyne homocoupling and Cope-type hydroamination of the intermediary 1,3-diynes in the presence of hydrazine as nucleophilic reaction partner. The proposed multistep methodology offers an easy and direct access to valuable pyrazoles from cheap and readily available starting materials and without the need for the isolation of any intermediates.

Method used for preparing pyrazole compounds in recoverable solvent

The invention provides a method used for preparing pyrazole compounds in a recoverable solvent. According to the method, 1,3-diyne and hydrazine are taken as raw materials, and DMSO/H2O is taken as a reaction solvent. The method comprises following advantages: reaction steps are few; raw materials are cheap; the solvent can be recycled conveniently; reaction conditions are mild; the method is friendly to the environment; product yield is high; purity is high; the obtained product is capable of satisfying requirements on quality of drug intermediates; an ideal approach is provided for industrialized production; and application prospect is promising.

Synthesis of 1,3,5-Trisubstituted Pyrazoles by the Cope-Type Hydroamination of 1,3-Dialkynes with Alkylhydrazines

An efficient method to synthesize 1,3,5-trisubstituted pyrazoles was developed. The reaction of 1,3-dialkynes with alkylhydrazines smoothly proceeded in dimethyl sulfoxide under suitable heating conditions to produce 1,3,5-trisubstituted pyrazoles in sati

Synthesis of 3,5-disubstituted pyrazoles via cope-type hydroamination of 1,3-dialkynes

An efficient method for the synthesis of 3,5-disubstituted pyrazoles is described. The reactions of 1,3-dialkynes with hydrazine proceeded smoothly in dimethyl sulfoxide under mild reaction conditions to produce 3,5-disubstituted pyrazoles in satisfactory to excellent yields. A one-pot procedure of the transformation has been developed.

One-pot four-component reaction for the generation of pyrazoles and pyrimidines

The palladium-catalysed four-component coupling of a halide, terminal alkyne, molybdenum hexacarbonyl and either a hydrazine or amidine has been shown to be an efficient method for the construction of highly substituted pyrazoles and pyrimidines, respectively, in a one-pot process. Georg Thieme Verlag Stuttgart.

The structure of pyrazoles in the solid state: A combined CPMAS, NMR, and crystallographic study

The structures of six N-unsubstituted pyrazoles, three already known and three newly synthesized, have been studied by a combination of X-ray crystallography, multinuclear NMR (solution and solid state), and density functional theory (DFT) calculations. I

β-Tosylhydrazono phosphonates in organic synthesis. An unambiguous entry to polysubstituted pyrazoles

β-Tosylhydrazono phosphonates are novel, bifunctional reagents which were used for a concise approach to a wide range of polysubstituted pyrazoles in a single operation from aromatic and aliphatic aldehydes.