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Upstream product

• 371-14-2 4-fluorophenylhydrazine 
• 123-54-6 acetylacetone 
• 352-34-1 4-fluoro-1-iodobenzene 
• 10199-63-0 1-(3,5-dimethyl-1H-pyrazol-1-yl)ethanone 
• 1765-93-1 4-fluoroboronic acid 
• 67-51-6 3,5-dimethyl-1H-pyrazole 
• 352-33-0 1-Chloro-4-fluorobenzene 
• 371-40-4 4-fluoroaniline 

Relevant academic research and scientific papers

Preparation method of pyrazole derivative

The present invention discloses a method for preparing a pyrazole derivative. The method comprises the following steps: the arylhydrazine derivative is mixed with an alkyldione derivative, reaction, to obtain a pyrazole derivative; wherein the structure of the arylhydrazine derivative is as follows: the structure of the alkyldione derivative is as follows: the structure of the pyrazole derivative provided by the present invention is green safe, simple and efficient, mild conditions, no catalyst, low cost, high synthesis efficiency. This method can synthesize a variety of 1,3,4,5-tetra-substituted pyrazole derivatives, and the method can be widely used in the field of organic synthesis.

Direct Preparation of N-Substituted Pyrazoles from Primary Aliphatic or Aromatic Amines

Despite a large number of synthesis procedures for pyrazoles known today, those directly employing primary amines as substrates are rare. Herein, we report an original method for the preparation of N-alkyl and N-aryl pyrazoles from primary aliphatic or aromatic amines as a limiting reagent of the reaction. The protocol utilizes no inorganic reagents and requires a short reaction time, mild conditions, and the use of structurally simple and commercially available starting reagents. During this study, pyrazoles containing a wide variety of N-substituents were obtained using the same procedure for both aliphatic and aromatic amines.

Cross-Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate-Determining Deprotonation of Bound Hydrazine

Reported here is the Pd-catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate-limiting deprotonation of a hydrazine-bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.

Visible-light enabled C4-thiocyanation of pyrazoles by graphite-phase carbon nitride (g-C3N4)

Thiocyanation is an important and effective way to form C[sbnd]S bonds in organic synthetic methodology. Especially, thiocyanation of pyrazole attracts the attention of many researchers because sulfur-containing compounds are widely applied in many crucial fields such as organic materials, agrochemistry, nanotechnology, etc. Herein, we described A rapid metal- and additive-free method for C(sp2)-H thiocyanation of pyrazoles under visible light at room temperature by using a sustainable catalyst of graphite-phase carbon nitride (g-C3N4) and a thiocyanating agent of ammonium thiocyanate. The method presents many advantages, such as usage of eco-friendly photoredox catalyst, a wide range of substrates and a good yield of products, etc.

Oxone-DMSO Triggered Methylene Insertion and C(sp2)-C(sp3)-H-C(sp2) Bond Formation to Access Functional Bis-Heterocycles

Metal-free insertion of a methylene group was achieved for the construction of a new C(sp2)-C(sp3)-H-C(sp2) bond in order to prepare novel bis-heterocyclic scaffolds. The complete mechanistic investigations included experimental study and DFT calculations, and various symmetric and unsymmetric bis-pyrazoles as well as other pyrazole-based bis-heterocyclic molecules were prepared in moderate to high yields. Further modification of the bridged methylene group in the unsymmetric pyrazoles generated a chiral center to extend the scope of this method.

Application and developing of iron-doped multi-walled carbon nanotubes (Fe/MWCNTs) as an efficient and reusable heterogeneous nanocatalyst in the synthesis of heterocyclic compounds

Iron-doped multi-walled carbon nanotubes (Fe/MWCNTs) is an efficient, ecofriendly and reusable heterogeneous nanocatalyst for the one-pot synthesis of heterocyclic compounds including bis-spiro piperidines, piperidines, dihydro-2-oxopyrroles, pyrazoles and diazepines at room temperature with good to excellent yields. The heterogeneous nanocatalyst was fully characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma (ICP) and FT-IR analysis. Also, the structures of all prepared compounds were characterized by 1H NMR, 13C NMR, FT-IR, mass spectrometry (MS) and elemental analysis. The major advantages of these protocols are mild and green reaction conditions, short reaction times, clean reaction, operational simplicity, easy purification and good to excellent yields with the reusable heterogeneous nanocatalyst. The catalyst was ten recycled without significant loss of activity.

PYRAZOLE DERIVATIVES

Provided herein are compounds of the formula I: as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment or prevention of mGluR5 mediated disorders, such as acute and/or chronic neurological disorders, cognitive disorders and memory deficits, as well as acute and chronic pain.

From Ligand to Phosphor: Rapid, Machine-Assisted Synthesis of Substituted Iridium(III) Pyrazolate Complexes with Tuneable Luminescence

A first-generation machine-assisted approach towards the preparation of hybrid ligand/metal materials has been developed. A comparison of synthetic approaches demonstrates that incorporation of both flow chemistry and microwave heating can be successfully applied to the rapid synthesis of a range of new phenyl-1H-pyrazoles (ppz) substituted with electron-withdrawing groups (?F, ?CF3, ?OCF3, and ?SF5). These, in turn, can be translated into heteroleptic complexes, [Ir(ppz)2(bipy)]BF4 (bipy=2,2′-bipyridine). Microwave-assisted synthesis for the IrIII complexes allows isolation of spectroscopically pure species in less than 1 h of reaction time starting from IrCl3. All of the new complexes have been characterised photophysically (including nanosecond time-resolved transient absorption spectroscopy), electrochemically, and by TD-DFT studies. The complexes exhibit ligand-dependent, tuneable, green-yellow luminescence (500–560 nm), with quantum yields in the range 5–15 %.

Copper-catalyzed C–N cross-coupling of arylboronic acids with N-acylpyrazoles

A copper-catalyzed C–N bond forming reaction of arylboronic acids and N-acylpyrazoles was developed. This procedure used N-acetyl protected pyrazoles as starting material instead of free pyrazoles (NH). The reaction worked under neutral conditions and did not require any base or ligand. The reaction showed good functional group tolerance.

Diazirines as potent electrophilic Nitrogen sources: Application to the synthesis of Pyrazoles

Even after more than 50 years since its discovery, the electrophilic potential of diazirines was never truly exploited. This longstanding limitation has been resolved. N-Monosubstituted diaziridines and hydrazones are obtained by nucleophilic additions. They release, under hydrolysis conditions, the corresponding monosubstituted hydrazines. The latter were converted to pyrazoles in high yields. The adamantanone can be recovered in 80-100% yields. This work demonstrates the potential of diazirines as electrophilic nitrogen sources with recoverable protecting groups.