Pyrazole Moiety Research Articles

Sydnone: Synthesis, Reactivity and Biological Activities.

Sydnones are among the most well-known mesoionic compounds. Since their synthesis in 1935 by Earl and Mecknay, numerous researches have shown that the chemical behavior, physical and biological properties of sydnones make them the most useful compounds in organic chemistry. Sydnones undergo thermal 1,3-dipolar cycloaddition reaction with dipolarophiles (alkynes or alkenes) to give exclusively derivatives containing a pyrazole moiety exhibiting numerous applications, such as pharmaceuticals and agrochemicals. However, the sydnone cycloaddition reaction with alkynes requires harsh conditions, like high temperatures and long reaction times, giving poor regioselectivity to the resulting products. To overcome these constraints, new reactions named CuSAC (Copper- Catalyzed Sydnone-Alkyne Cycloaddition) and SPSAC (Strain-Promoted Sydnone- Alkyne Cycloaddition) have been developed, leading to pyrazoles with interesting constant kinetics.

A Brief Review on the Design, Synthesis and Biological Evaluation of Pyrazolo[c]coumarin Derivatives

Both pyrazole and coumarin moiety are important scaffolds for their natural occurrences as well as a broad spectrum of pharmaceutical properties. When coumarin fuses with pyrazole containing a diverse functionality, synergic effect may be observed in the field of medicinal and material chemistry. Owing to their various functionality on the pyrazole as well as coumarin moiety of the title compounds, they possess fantastic biological properties including antimicrobial, antiproliferative, CpIMPDH inhibition, α-glucosidase inhibition, selective hCA IX inhibition as well as anticancer activities. Some architectural pyrazolo[c]coumarin derivatives were reported to be used in bipolar host materials and blue TADF-OLEDs. For these reasons, a special attention has been paid to researchers for the searching of new, greener and efficient protocols for the design and synthesis of pyrazolo[c]coumarins to evaluate their biological activities. This paper reviews the research data in the literature on the synthetic strategies for structurally designed pyrazolo[c]coumarin derivatives. Furthermore, the biological properties of these synthesized compounds are described by highlighting their mode of interactions with different cells and enzymes.

Novel Thiopyrano[2,3-d]thiazole-pyrazole Hybrids as Potential Nonsulfonamide Human Carbonic Anhydrase IX and XII Inhibitors: Design, Synthesis, and Biochemical Studies.

In recent years, molecular hybridization strategies have developed into a potent strategy for drug discovery. A series of novel thiopyrano[2,3-d]thiazoles linked to the pyrazole moiety was designed and developed as anticancer agents by a molecular hybridization. Target compounds were synthesized and characterized by spectroscopic tools as well as X-ray crystallography analysis as in the case of thiopyrano[2,3-d]thiazole derivative 5a. The MTT assay was used to demonstrate the in vitro efficacy of compounds 5a-g and 7a-j on MCF-7 and HePG-2. The results showed that some cycloadducts such as bromophenyl-4-thioxo-2-thiazolidinone 3e, 4-methylphenyl derivative of thiopyrano[2,3-d]thiazole 5d, and 6-substituted-thiopyrano[2,3-d]thiazoles 7e-j displayed good to excellent IC50 in the range of 10.08 ± 1.5 to 25.95 ± 2.8 μg/mL against the MCF-7 cell line and from 7.83 ±2.1 to 13.37 ± 1.2 μg/mL against the HePG-2 cell line. To explore the enzymatic tests for isozymes hCAIX and hCAXII, the most promising eight compounds 3e, 5d, and 7e-j with IC50 ranging from 7.83 ± 2.1 to 25.95 ± 2.8 μM were chosen. Compound 7e exhibited an IC50 (0.067 ± 0.003 μM) similar to that of the standard drug AZA against CAIX (0.059 ± 0.003 μM)). For CAXII, the compound 7i had an IC50 equal to 0.123 ± 0.007 μM compared to that of AZA (0.083 ± 0.005 μM). In addition, using flow cytometry, cell cycle analysis and apoptosis studies in HePG-2 were performed for the two potent anticancer and selective carbonic anhydrase agents (7e and 7i). An enzymatic assay of these two compounds against caspase-9 was also examined. Interestingly, the molecular docking studies revealed that compounds 7e and 7i successfully embedded themselves in the active pockets of the CAIX and CAXII enzymes through different interactions. Overall, the novel thiopyrano[2,3-d]thiazole-pyrazole hybrids (7e and 7i) were suggested to be potent and selective inhibitors of CAIX and CAXII.

In vitro DNA Binding Interaction Studies of Hydrazones and Thiosemicarbazones Derived from Pyrazole Moiety

In this work, the novel hydrazones and thiosemicarbazones derived from pyrazole moieties were synthesized by reacting 4-chloro-1-methyl-1H-pyrzolecarboxaldehyde with various hydrazides and thiosemicarbazides. All the synthesized compounds were characterized and confirmed with different spectroscopic techniques like FTIR, 1H NMR and LC-MS. The ct-DNA binding interaction studies were evaluated by using UV-visible spectroscopic and fluorescence spectrophotometric techniques with calf thymus DNA. The obtained binding constants of the synthesized were found to be 7 [8.44 × 104] > 4 [3.61 × 104] > 2 [3.60 × 104] > 1 [3.18 × 104] > 8 [2.85 × 104 M-1].

STING antagonists, synthesized via Povarov-Doebner type multicomponent reaction.

The cGAS-STING axis plays an important role in protecting higher organisms against invading pathogens or cancer by promoting the production of cytokines and interferons. However, persistent or uncontrolled activation of this pathway could lead to inflamed environments, which is detrimental to the host in the long run. Persistent activation of STING is known to be the cause of STING-associated vasculopathy with onset in infancy (SAVI) and activated STING is believed to play important roles in worsening various diseased states, such as traumatic brain injury, diabetic kidney disease and colitis. Thus, antagonists of STING could play important roles in managing various inflammatory diseases. Herein, we report the discovery of small molecule STING inhibitors, HSD1077 and analogs, which are facilely synthesized via a Povarov-Doebner type three-component reaction involving an amine, ketone, and aldehyde. Structure-activity relationship, SAR, studies indicate that both the 3H-pyrazolo[4,3-f]quinoline and pyrazole moieties in HSD1077 are critical for STING binding. At concentrations as low as 20 nM, HSD1077 suppressed type-1 interferon expression in both murine RAW macrophages and human THP-1 monocytes upon treatment with 100 μM 2'-3' cGAMP. Compounds containing the 3H-pyrazolo[4,3-f]quinoline moiety have the potential to be translated into anti-inflammatory compounds via STING inhibition.

A coumarin-pyrazole-based probe for the fluorescence detection of phosgene with high selectivity and sensitivity.

The high toxicity of phosgene poses potential threats to public health and safety. In this work, a novel fluorescent probe was designed to detect phosgene using hydroxyl and pyrazole moieties as the recognition sites. The response to phosgene with probe 1 was fast (less than 30 s), highly selective and sensitive with the limit of detection being 4.78 nM in solution. Furthermore, probe 1 was employed to conveniently fabricate paper test strips for efficiently detecting phosgene gas. The limit of detection was obtained as 0.014 ppm by using a smartphone RGB app, revealing that probe 1 has good prospects for sensitively detecting phosgene gas.

Five and six membered heterocyclic rings endowed with azobenzene as dual EGFRT790M and VEGFR-2 inhibitors: design, synthesis, in silico ADMET profile, molecular docking, dynamic simulation and anticancer evaluations.

Novel azobenzene scaffold-joined heterocyclic isoxazole, pyrazole, triazole, and/or triazine moieties have been developed and synthesized utilizing microwave and traditional methods. Our compounds were tested for growth inhibition of A549, MCF-7, HCT-116, and HepG2 tumors by dual targeting the VEGFR-2 and EGFRT790M enzymes. The suggested compound's manner of binding with EGFRT790M and VEGFR-2 active sites was explored through molecular design and MD modeling. The information from the results of the biological screening and the docking studies was highly correlated. The A549 cell line was the one that responded to the novel compound's effects most effectively. Having IC50 values of 5.15, 6.37, 8.44 and 6.23 μM, respectively, 14 was the most effective derivative on the four A549, MCF-7, HCT116 and HepG2 cancer cells. It had greater activity than erlotinib and slightly inferior activities on the tested cell lines than sorafenib, respectively. The cytotoxicity of the most effective derivatives, 5, 6, 10 and 14, was evaluated against typical VERO cell lines. Having IC50 values ranging from 42.32 to 55.20 μM, the results showed that the investigated drugs have modest toxicity against VERO normal cells. Additionally all derivatives were assessed for their dual VEGFR-2 and EGFRT790M inhibitory effects. Among them, derivatives 14, 5 and 10 were established as the greatest inhibitors of VEGFR-2 at IC50 values of 0.95, 1.25 and 1.50 μM correspondingly. As well, derivatives 14, 6, 5 and 10 could inhibit EGFRT790M activity demonstrating strongest effects with IC50 = 0.25, 0.35, 0.40 and 0.50 μM respectively. Furthermore, the ADMET profile was evaluated for compounds 5, 6, 10 and 14 in contrast to reference drugs sorafenib and erlotinib.

Quantitative Structure-Activity relationship, Molecular Docking and ADMET Screening of Tetrahydroquinoline Derivatives as Anti-Small Cell Lung Cancer Agents

Lung carcinoma (LC) is responsible for almost one-third of all cancer fatalities worldwide. Tetrahydroquinoline is an organic molecule that is the semi-hydrogenated derivative of quinoline and could be found in several naturally occurring compounds such as flindersine, oricine etc. Some tetrahydroquinoline derivatives with pyrazole and hydrazide moieties were evaluated in silico against A549 (human lung cancer cell lines). The quantitative structural-activity relationship (QSAR) model created was statistically significant with validation metrics of R2 (0.9525), R2adj (0.9314), and CV.R (0.9719). The molecular docking analysis revealed that compound C14 demonstrated the best binding affinity towards the studied protein with binding affinity value of –10.1 kcal mol–1 (4LRM). This is in accordance with the experimental result (IC50 = 0.69). The factors observed for ADME&T correlated well with the factors observed for the referenced drug. This study indicates that compounds C1 and C9 can be further developed as anti-epidermal growth factor receptor (EGFR) compounds. Thus, our findings may open door for the design and development of library of efficient Tetrahydroquinoline-based drug-like compounds as potential anti-LC agents.

Ultrasonic-Assisted Regioselective Reactions and Quantum Chemical Study of Pyrimidin-2- Thione Carrying Pyrazole Moiety as Algaecides for Refining Wastewater

Ultrasonic-Assisted Regioselective Reactions and Quantum Chemical Study of Pyrimidin-2- Thione Carrying Pyrazole Moiety as Algaecides for Refining Wastewater

Exploration of type II and III collagen binding interactions with short peptide-phenyl pyrazole conjugates via docking, molecular dynamics and laboratory experiments

ABSTRACT Interaction with components of the extracellular matrix, particularly various forms of collagen, is essential for the design of successful scaffolds for tissue engineering applications. Both Type II and Type III collagen are found in various connective tissues in the body, providing stability, wound healing, and in some cases assisting in fibrillogenesis. In this study, we designed short peptide conjugates with phenyl pyrazole moieties and examined their interactions with Type II and III triple helical collagen models. The number of hydrophobic groups was varied by varying the phenyl pyrazole moieties that were conjugated with three separate peptides (SYED; SLKD and SLYD). Molecular dynamics (MD) and docking studies revealed that in most cases conjugating with phenyl pyrazole improved binding affinity and stability compared to neat peptides. Computational studies were also carried out to examine the formation of stable scaffold assemblies using MD simulations by integrating the peptide conjugates with either Type II or III collagen and chondroitin sulfate, in order to mimic the formation of a scaffold. As a proof of concept, we examined the binding interactions of the short peptides with Type II and III collagen using SPR and CD spectroscopy, and then synthesized two of the peptide conjugates and integrated them with either Type II or Type III collagen and chondroitin sulfate by layer-by-layer assembly to develop scaffolds to validate computational results. AFM imaging showed the formation of fibrillary structures. The cytocompatibility of the scaffolds was then examined in the presence of mesenchymal stem cells, that showed the formation of cell-scaffold matrices particularly with SLYD conjugates. Our results indicate that such peptide-pyrazole conjugates, may be developed for designing scaffolds for tissue engineering applications.

Polysorbate 21 Can Modulate the Antibacterial Potential of Two Pyrazol Derivatives

The combination of two compounds with known antimicrobial activity may, in some cases, be an effective way to limit the resistance to antibiotics of specific pathogens. Molecules carrying pyrazole moiety are well known for their bioactive properties and have wide applicability in the medical and pharmaceutical field. Surfactants have, among other useful properties, the ability to affect the growth of microorganisms. The paper reports on the effect of the combination of two pyrazole derivatives, (1H-pyrazol-1-yl) methanol 1-hydroxymethylpyrazole (SAM1) and 1,1'methandiylbis (1H-pyrazol) (AM1), with sorbitan monolaurate (polysorbate 21, Tween 21, T21) on the growth of Gram-positive and Gram-negative bacteria. The results demonstrated a different ability of this combination to inhibit Staphylococcus aureus and Escherichia coli. T21 intensified the inhibitory activity of the pyrazoles to a greater extent in the Gram-negative bacteria compared to the Gram-positive ones, a fact confirmed by time-kill experiments. The experimental data showed that the association of T21 with the pyrazoles led to the increased release of intracellular material and a more intense uptake of crystal violet, which indicates that the potentiation of the antibacterial effect was based on the modification of the normal permeability of bacterial cells. T21 acted as a modulating factor and increased the permeability of the membrane, allowing the accelerated penetration of the pyrazoles inside the bacterial cells. This fact is important in controlling the global increase in microbial resistance to antibiotics and antimicrobials and finding viable solutions to overcome the antibiotic crisis. The paper highlights the possibility of using non-toxic surfactant molecules in antimicrobial combinations with practical applications. This could widen the range of adjuvants in applications which would be useful in the control of resistant microorganisms.

Phosphonic acid tagged carbon quantum dots encapsulated in SBA-15 as a novel catalyst for the preparation of N-heterocycles with pyrazolo, barbituric acid and indole moieties

Herein, we have presented a new insight for the synthesis of a hybrid heterogeneous catalyst. For this purpose, phosphonic acid tagged carbon quantum dots of CQDs-N(CH2PO3H2)2 encapsulated and assembled in channels of SBA-15 using a post-modification strategy. The mesoporous catalyst of functionalized carbon quantum dots (CQDs) was characterized by several techniques. CQDs-N(CH2PO3H2)2/SBA-15 as an excellent catalyst was applied for the preparation of novel pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrimidine derivatives by using pyrazole, barbituric acid and indole moieties at 100 °C under the solvent-free condition. The present work shows that a significant increase in the catalytic activity can be achieved by a rational design of mesoporous SBA-15 modified with CQDs for the synthesis of biological active candidates. The synthesized compounds did not convert to their corresponding pyridines via an anomeric-based oxidation mechanism.

Structural Basis for Inhibition of Mutant EGFR with Lazertinib (YH25448).

Lazertinib (YH25448) is a novel third-generation tyrosine kinase inhibitor (TKI) developed as a treatment for EGFR mutant non-small cell lung cancer. To better understand the nature of lazertinib inhibition, we determined crystal structures of lazertinib in complex with both WT and mutant EGFR and compared its binding mode to that of structurally related EGFR TKIs. We observe that lazertinib binds EGFR with a distinctive pyrazole moiety enabling hydrogen bonds and van der Waals interactions facilitated through hydrophilic amine and hydrophobic phenyl groups, respectively. Biochemical assays and cell studies confirm that lazertinib effectively targets EGFR(L858R/T790M) and to a lesser extent HER2. The molecular basis for lazertinib inhibition of EGFR reported here highlights previously unexplored binding interactions leading to improved medicinal chemistry properties compared to clinically approved osimertinib (AZD9291) and offers novel strategies for structure-guided design of tyrosine kinase inhibitors.

Exploring Arylazo-3,5-Bis(trifluoromethyl)pyrazole Switches.

Arylazopyrazoles stand out among the azoheteroarene photoswitches due to their excellent properties in terms of stability of the least stable isomer and conversion between isomers, leading to their use in several interesting applications. We report herein the synthesis of arylazo-trifluoromethyl-substituted pyrazoles and their switching behavior under light irradiation. UV-vis and NMR experiments showed that arylazo-1H-3,5-bis(trifluoromethyl)pyrazoles displayed very long half-lives in DMSO (days), along with reasonable values of other parameters that characterize a photoswitch. Inclusion of naphthyl moieties as aryl counterparts of the arylazopyrazoles is beneficial only in combination with trifluoromethyl groups, while extending the conjugation by grafting the pyrazole moiety with electron-donating or -withdrawing substituents positively affects the photoswitching behavior, in terms of isomerization yield and half-lives of the least stable isomer. The experimental values were correlated with theoretical calculations indicating the valuable influence of the trifluoromethyl groups onto the photoswitching behavior.

Rational Synthesis of an Unsymmetric Pt Complex Unit Having Two Kinds of Pyrazolate Ligands: Elucidating Steric and Electronic Effects of Pyrazolate Ligands in Pt‐Ag Sandwich Complexes

AbstractHerein we report the rational synthesis of an unsymmetric Pt complex containing two different pyrazole ligands and a selective formation of Z‐shaped Pt2Ag2 complex using the unsymmetric Pt complex unit, whose structures were undoubtedly revealed by X‐ray crystallographic analysis in the solid state and NMR analysis in the solution state. The selective formation of the unsymmetric Pt and Pt2Ag2 complexes enable us to reveal that the steric effect from the pyrazole ligands determine the orientation of the Pt complex units but hardly influence on the photophysical properties of the complexes. The TD‐DFT calculations of the Pt and Pt2Ag2 complexes supported the small electronic contributions of pyrazole moieties. This synthetic route will build up a new strategy to obtain new types of precious metal sandwich complexes.

Analysis of fluoro based pyrazole analogues as a potential therapeutics candidate against Japanese encephalitis virus infection

Japanese encephalitis virus (JEV) is the leading causative agent of encephalitis and its associated mortality among children. JEV modulates host cell machinery for its advantage, such as oxidative damage which subsequently leads to stress responsive pathways. The present study analyzes new series of dinitroaryl substituted derivatives (1a-1f), containing pyrazole moiety and explores its potential ensuing anti-JEV activity. Out of all synthesized derivatives, compounds 1b and 1f were selected based on minimal cytotoxicity. In vitro inhibition of more than 70% and 90% were observed with compounds 1b and 1f, respectively, in neuronal cells. Dose-response analyses highlighted 1f exhibiting better antiviral activity than 1b. The mice treated with compound 1b or 1f did not show any noticeable toxicity at a dose of 100mg/kg/day when administered intraperitoneally till 96th h. Inhibition of up to 41% and 70% JEV mRNA in spleen and 33% to 43% in brain tissue was observed with compounds 1b and 1f, respectively. Both the compounds suppressed JEV induced ROS generation by up-regulating the NQO1 and HO-1 proteins. Our result suggests the interlocked positive feedback loops of NRF2-SQSTM1 signaling pathway to be regulated by the synthesized compounds. The potential of these compounds can be further tested for broad-spectrum antiviral effects with other flaviviruses in the path towards the development of therapeutics.

Synthesis and structural characterization of a series of Co(II) NNN pincer complexes

Several new Co(II) complexes supported by CztBu(PyriPr)2– ligand(s) in various ligand-to-metal ratios are reported. The synthesis and characterization of CztBu(PyriPr)2Co (1) completes a series of analogous compounds (CztBu(PyriPr)2M, M = Fe(II), Co(II), Ni(II)), offering insights into chemical trends across late first-row transition metal complexes. Additionally, chemical oxidation of (CztBu(PyriPr)2)2Co (2) gave complex 5, in which unprecedented, cobalt-facilitated CC coupling of pyrazole moieties has occurred.

Pyrazole Containing Anti-HIV Agents: An Update

Pyrazole scaffolds have gained importance in drug discovery and development for various pharmacological activities like antiviral, antifungal, anticancer, antidepressant, antiinflammatory, antibacterial, etc. Additionally, the pyrazole moiety has shown potent anti-HIV activity as a core heterocycle or substituted heterocycles derivatives (mono, di, tri, tetra, and fused pyrazole derivatives). To assist the development of further potential anti-HIV agents containing pyrazole nucleus, here we have summarized pyrazole containing anti-HIV compounds that have been reported by researchers all over the world for the last two decades. The present review concentrates on an assortment of pyrazole containing compounds, particularly for potential therapeutic activity against HIV. Google Scholar, Pubmed, and SciFinder were searched databases with ''pyrazol'' keywords. Further, the year of publication and keywords ''Anti-HIV'' filter was applied to obtain relevant reported literature for anti-HIV agents containing pyrazole as a core or substituted derivatives. This review article has shown the comprehensive compilation of 220 compounds containing pyrazole nucleus and possessing anti-HIV activity by sorting approximately 40 research articles from 2001 to date. 1-(4-Benzoylpiperazin-1-yl)-2-(4-fluoro-7-(1H-pyrazol-3-yl)-1H-pyrrolo[2,3-c]pyridin- 3-yl)ethane-1,2-dione (13), 3-(3-(2-(4-benzoylpiperazin-1-yl)-2-oxoacetyl)-4-fluoro-1H-pyrrolo[2,3- c]pyridin-7-yl)-1H-pyrazole-5-carboxamide (31), 3-(3-(2-(4-benzoylpiperazin-1-yl)-2-oxoacetyl)-4- fluoro-1H-pyrrolo[2,3-c]pyridin-7-yl)-1H-pyrazole-5-carboxamide (88), 3-cyanophenoxypyrazole derivative (130), and 4-(4-chlorophenyl)-5-(4-methyl-5-((4-nitrophenyl)diazenyl)thiazol-2-yl)-3- phenyl-5,6-dihydro-4H-pyrazolo[4,3-d]isoxazole (178) were the most potent mono-, di-, tri-, tetrasubstituted, and fused pyrazole derivatives, respectively, which have shown potent anti-HIV activity among all the described derivatives as compared with standard anti-HIV drugs. This review article provides an overview of the potential therapeutic activity of pyrazole derivatives against HIV that will be helpful for designing pyrazole containing compounds for anti-HIV activity.

Design and Synthesis of Novel Celecoxib Analogues with Potential Cytotoxic and Pro-apoptotic Activity against Breast Cancer Cell Line MCF-7.

Breast cancer is currently the leading cause of worldwide cancer incidence exceeding lung cancer. In addition, breast cancer accounts for 1 in 4 cancer cases and 1 in 6 cancer deaths among women. Cytotoxic chemotherapy is still the main therapeutic approach for patients with metastatic breast cancer. The aim of the study was to synthesize a series of novel celecoxib analogues to evaluate their anticancer activity against the MCF-7 cell line. Our design of target compounds was based on preserving the pyrazole moiety of celecoxib attached to two phenyl rings, one of them having a polar hydrogen bonding group (sulfonamide or methoxy group). The methyl group of the second phenyl ring was replaced with chlorine or bromine atom. Finally, the trifluoromethyl group was replaced with arylidene hydrazine-1-carbonyl moiety, which is substituted either with fluoro or methoxy group, offering various electronic and lipophilic environments. These modifications were carried out to investigate their effects on the antiproliferative activity of the newly synthesized celecoxib analogues and to provide a valuable structure- activity relationship. Four compounds, namely 4e-h, exhibited significant antitumor activity. Compounds 4e, 4f and 4h showed 1.2-2 folds more potent anticancer activity than celecoxib. Celecoxib analogue 4f showed the most potent anti-proliferative activity. Its anti-proliferative activity seems to associate well with its ability to inhibit BCL-2. Moreover, activation of the damage response pathway of the DNA leads to cell cycle arrest at the G2/M phase and accumulation of cells in the pre-G1 phase, indicating that cell death proceeds through an apoptotic mechanism. Compound 4f exhibited a potent pro-apoptotic effect via induction of the intrinsic mitochondrial pathway of apoptosis. This mechanistic pathway was proved by a significant increase in the expression of the tumor suppressor gene p53, elevation in Bax/BCL-2 ratio, and a significant increase in the level of active caspase-7. Furthermore, compound 4f showed moderate COX-2 inhibitory activity. Celecoxib analogue 4f is a promising multi-targeted lead for the design and synthesis of potent anticancer agents.

Intramolecular oxidative C–N bond formation under metal-free conditions: One-pot global functionalization of pyrazole ring

Herein, we report an efficient DTBP promoted and NaI-catalyzed, greener protocol for the synthesis of highly substituted pyrazoles via C(sp2)–H bond functionalization. This protocol is general and the reaction efficacy improves significantly with the combined use of solvents t-BuOH and EtOH, producing a vast variety of substituted pyrazoles in good to excellent yields. The mechanistic investigations including the radical trapping experiment indicating the in-situ generation of intermediate free-radical species followed by intramolecular oxidative C–N bond formation afforded the desired pyrazole moiety. The synthetic versatility of this methodology is further highlighted by preparing a diverse range of substrates including di-/tri-/and tetra-substituted pyrazoles, and applying the methodology in the practical synthesis of bioactive scaffolds.