33045-40-8

Usage

Chemical class

Pyrazole class of organic compounds

Composition

Pyrazole ring with two phenyl groups at positions 1 and 5, and a 4-methoxyphenyl group at position 3

Potential applications

Medicine, agriculture, and materials science

Drug candidate

Treatment of neurological disorders and cancer

Pesticidal properties

Investigated for use as a crop protection agent

Molecular structure

Unique structure, promising for development of new materials and dyes

InChI:InChI=1/C22H18N2O/c1-25-20-14-12-17(13-15-20)21-16-22(18-8-4-2-5-9-18)24(23-21)19-10-6-3-7-11-19/h2-16H,1H3

Upstream product

• 64-19-7 acetic acid 
• 1450-62-0 C₂₂H₂₀N₂O⁽¹⁺⁾ 
• 22966-19-4 trans-4'-methoxychalcone 
• 100-63-0 phenylhydrazine 
• 100-42-5 styrene 
• 20433-10-7 5-(4-methoxyphenyl)-2-phenyl-2H-tetrazole 
• 123-11-5 4-methoxy-benzaldehyde 
• 536-74-3 phenylacetylene 
• 100-07-2 4-methoxy-benzoyl chloride 
• 16616-43-6 1-(4-methoxy-phenyl)-3-phenyl-propynone 
• 201230-82-2 carbon monoxide 
• 59-88-1 phenylhydrazine hydrochloride 
• 768-60-5 4-methoxyphenylacetylen 
• 959-23-9 4'-methoxychalcone 

Downstream Products

• 289725-84-4 4-iodo-3-(4-methoxyphenyl)-1,5-diphenyl-1H-pyrazole 

Relevant academic research and scientific papers

Photooxidation of 3,5-diaryl-1-phenyl-2-pyrazolines: Experimental and computational studies

Photooxidation of various 2-pyrazolines is studied experimentally and computationally. Experimental results show that the electron-donating/withdrawing substituents increases/decreases the rate of this photoreaction. The proposed light-induced electron-tr

Fast and Efficient Continuous Flow Method for the Synthesis of Ynones and Pyrazoles

In this study, we developed a convenient and efficient two-step method for the synthesis of ynones in a flow reactor, through the generation of lithium acetylide and its subsequent reactions with acid chlorides. Using this approach, we obtained the ynones in moderate to good yields at room temperature. Moreover, we transformed the ynones into pyrazole derivatives through coupling with hydrazines. This transition metal-free process, mild reaction conditions, and broad functional group tolerance are all attractive features in comparison with conventional bench-top methods.

Visible light mediated metal-free oxidative aromatization of 1,3,5-trisubstituted pyrazolines

The visible light mediated oxidation of 1,3,5-trisubstituted pyrazolines under metal-free conditions was developed. Various substituted pyrazolines were oxidized to pyrazoles by irradiation with visible light/sunlight. A plausible mechanism was proposed f

One-pot regioselective synthesis of substituted pyrazoles and isoxazoles in PEG-400/water medium by Cu-free nano-Pd catalyzed sequential acyl Sonogashira coupling-intramolecular cyclization

Catalyst efficacy of in situ generated Pd-nanoparticles (PdNPs) in the regioselective one-pot synthesis of 3,5-di & 3,4,5-trisubstituted pyrazoles and 3,5-disubstituted isoxazoles in environmentally benign PEG-400/H2O medium, which involves the sequential (i) Cu-free acyl-Sonogashira coupling (ASC) and (ii) intramolecular ynone-amine cyclization under PTC conditions was described. The results of controlled experiments support the operation of two sequential catalytic cycles (ASC/cyclization) and achievement of complementary/opposite regioselectivity via ynone-bound palladium in a one-pot approach. Moreover, the in situ PdNPs recovered after the first catalytic cycle of the one-pot reaction sequence have been reused again five times successively. Besides, prior to the above studies, the efficacy of some common Pd-N-heterocyclic carbene (Pd-NHC) complexes in catalyzing the same one-pot two-step reaction sequence (Cu-free ASC/cyclization) both in water and organic solvents was also optimized. In situ generation of PdNPs from above Pd-NHCs in water was also identified, but they are not reusable due to their large size distribution.

13C NMR spectroscopy of heterocycles: 1-phenyl-3-aryl/t-butyl-5-arylpyrazoles

A series of chalcones 1-12 were converted to pyrazolines (1Pi-12Pi) by reaction with phenylhydrazine followed by DDQ oxidation to produce the corresponding pyrazoles (1Pz-12Pz). Three 1-phenyl-3-t-butyl-5-arylpyrazoles (13Pz-15Pz) were synthesized using an analogous approach. Molecular modeling studies predicted the 5-aryl group of the pyrazoles for both series to have a torsion angle of 52°-54° whereas the 1-phenyl group was predicted to have 35°-37° torsion angles. The 3-aryl group was predicted to be essentially coplanar (-3°) with the pyrazole system in the first series. 13C NMR data for both series, 1Pz-12Pz and 13Pz-15Pz, were collected in DMSO-d6 at 50°C. A plot of the C4 chemical shifts for 1Pz-12Pz versus Hammet constants for 5-aryl substituents yielded a very good linear correlation (R2=0.96) with a slope of 1.5. The chemical shift data for C4 showed little or no dependence on 3-aryl substituents. The result for 13Pz-15Pz, despite only three points, was consistent with the first series results and yielded a ρ value of 2.0. Distal transmission of substituent effects (5-aryl groups) to C4 of the pyrazole system was reduced by roughly 50-60% of that of the analogous planar isoxazole system, but are not consistent with results for the similarly twisted 4-bromoisoxazoles.

A Regioselective Approach to Trisubstituted Pyrazoles via Palladium-Catalyzed Oxidative Sonogashira-Carbonylation of Arylhydrazines

A palladium-catalyzed oxidative carbonylation of arylhydrazines and alkynes with balloon pressure CO/O2 to afford trisubstituted pyrazoles in a one-pot manner has been developed. The formation of trisubstituted pyrazoles involves a sequential C-N bond cleavage, carbonylation, Sonogashira coupling, Michael addition, and intramolecular condensation cyclization tandem process. An unprecedented oxidative Sonogashira-carbonylation reaction of arylhydrazine plays a key role for such a facile approach to pyrazoles.

Radical Addition of Hydrazones by α-Bromo Ketones to Prepare 1,3,5-Trisubstituted Pyrazoles via Visible Light Catalysis

A novel efficient tandem reaction of hydrazones and α-bromo ketones is reported for the preparation of 1,3,5-trisubstituted pyrazoles by visible light catalysis. In this system, the monosubstituted hydrazones show wonderful reaction activity with alkyl radicals, generated from α-bromo ketones. A radical addition followed by intramolecular cyclization affords the important pyrazole skeleton in good to excellent yields. This efficient strategy under mild conditions with wide group tolerance provides a potential approach to the 1,3,5-trisubstituted pyrazoles.

One-Pot Coupling-Coupling-Cyclocondensation Synthesis of Fluorescent Pyrazoles

Consecutive four-component coupling-coupling-cyclocondensation syntheses of pyrazoles and pyrimidines were developed by taking advantage of the provisional, sequentially Pd-catalyzed one-pot generation of alkynones from aryl iodides, ethynylmagnesium bromide, and acid chlorides. This one-pot methodology allows the concise, diversity-oriented generation of a set of donor-, acceptor-, and donor-acceptor-substituted pyrazoles, which are interesting fluorophores. Most distinctly, donor-acceptor pyrazoles display remarkably red-shifted emission maxima and pronounced positive solvochromicity, spanning an overall range from 363 nm (cyclohexane) to 595 nm (acetonitrile). DFT and TD-DFT calculations elucidate the electronic structure and the photophysical behavior. Upon photonic excitation, considerable charge-transfer character becomes apparent, which rationalizes the origin of huge Stokes shifts and solvochromic behavior.

Molecular iodine: A green and inclusive catalyst for the synthesis of highly functionalized 1,3,5-trisubstituted pyrazoles in aqueous medium

A library of 1,3,5-trisubstituted pyrazoles was synthesized in excellent yields from the reaction of aldehyde, phenylhydrazine and alkynes in the presence of iodine via an eco-friendly, simple process performed in aqueous medium. This single pot transformation generates new CN, C-C, C-N bonds and proceeds by a domino reaction involving the formation of Schiff base, Mannich addition and finally intramolecular cyclisation. The Royal Society of Chemistry 2014.

Facile one-pot synthesis of 1,3,5-trisubstituted pyrazoles from α,β-enones

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.