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Mutations in five canonical Ras pathway genes (NF1, NRAS, KRAS, PTPN11 and CBL) are detected in nearly 90% of patients with juvenile myelomonocytic leukemia (JMML), a frequently fatal malignant neoplasm of early childhood. In this report, we describe seven patients diagnosed with SH2B3-mutated JMML, including five patients who were found to have initiating, loss-of-function mutations in the gene. SH2B3 encodes the adaptor protein LNK, a negative regulator of normal hematopoiesis upstream of the Ras pathway. These mutations were identified to be germline, somatic or a combination of both. Loss of function of LNK, which has been observed in other myeloid malignancies, results in abnormal proliferation of hematopoietic cells due to cytokine hypersensitivity and activation of the JAK/STAT signaling pathway. In vitro studies of induced pluripotent stem cell-derived JMML-like hematopoietic progenitor cells also demonstrated sensitivity of SH2B3-mutated hematopoietic progenitor cells to JAK inhibition. Lastly, we describe two patients with JMML and SH2B3 mutations who were treated with the JAK1/2 inhibitor ruxolitinib. This report expands the spectrum of initiating mutations in JMML and raises the possibility of targeting the JAK/STAT pathway in patients with SH2B3 mutations.

UNLABELLED: We sought to evaluate the efficacy of WEE1 inhibitor adavosertib in patients with solid tumor malignancies (cohort A) and clear cell renal cell carcinoma (ccRCC; cohort B). NCT03284385 was a parallel cohort, Simon two-stage, phase II study of adavosertib (300 mg QDAY by mouth on days 1-5 and 8-12 of each 21-day cycle) in patients with solid tumor malignancies harboring a pathogenic SETD2 mutation. The primary endpoint was the objective response rate. Correlative assays evaluated the loss of H3K36me3 by IHC, a downstream consequence of SETD2 loss, in archival tumor tissue. Eighteen patients were enrolled (9/cohort). The median age was 60 years (range 45-74). The median duration of treatment was 1.28 months (range 0-24+). No objective responses were observed in either cohort; accrual was halted following stage 1. Minor tumor regressions were observed in 4/18 (22%) evaluable patients. Stable disease (SD) was the best overall response in 10/18 (56%) patients, including three patients with SD > 4 months. One patient with ccRCC remains on treatment for >24 months. The most common adverse events of any grade were nausea (59%), anemia (41%), diarrhea (41%), and neutropenia (41%). Nine patients (50%) experienced a Grade ≥3 adverse event. Of eight evaluable archival tissue samples, six (75%) had a loss of H3K36me3 by IHC. Adavosertib failed to exhibit objective responses in SETD2-altered ccRCC and other solid tumor malignancies although prolonged SD was observed in a subset of patients. Combination approaches may yield greater depth of tumor response. SIGNIFICANCE: WEE1 inhibition with adavosertib monotherapy demonstrated limited clinical activity in patients with SETD2-altered solid tumors despite compelling preclinical data indicating a synthetic lethal effect, which did not translate into robust tumor regression. Loss of the H3K36me3 trimethylation mark caused by SETD2-deficiency was confirmed in the majority of evaluable tumors. A subset of patients derived clinical benefit as manifested by minor tumor regressions and prolonged SD.

BACKGROUND: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are rare oncogenic drivers prevalent in 0.3% of solid tumors. They are most common in salivary gland cancer (2.6%), thyroid cancer (1.6%), and soft-tissue sarcoma (1.5%). Currently, there are 2 US Food and Drug Administration-approved targeted therapies for NTRK gene fusions: larotrectinib, approved in 2018, and entrectinib, approved in 2019. To date, the real-world uptake of tyrosine receptor kinase inhibitor (TRKi) use for NTRK-positive solid tumors in academic cancer centers remains largely unknown. OBJECTIVE: To describe the demographics, clinical and genomic characteristics, and testing and treatment patterns of patients with NTRK-positive solid tumors treated at US academic cancer centers. METHODS: This was a retrospective chart review study conducted in academic cancer centers in the United States. All patients diagnosed with an NTRK fusion-positive (NTRK1, NTRK2, NTRK3) solid tumor (any stage) and who received cancer treatment at participating sites between January 1, 2012, and July 1, 2023, were included in this study. Patient demographics, clinical characteristics, genomic characteristics, NTRK testing data, and treatment patterns were collected from electronic medical records and analyzed using descriptive statistics as appropriate. RESULTS: In total, 6 centers contributed data for 55 patients with NTRK-positive tumors. The mean age was 49.3 (SD = 20.5) years, 51% patients were female, and the majority were White (78%). The median duration of time from cancer diagnosis to NTRK testing was 85 days (IQR = 44-978). At the time of NTRK testing, 64% of patients had stage IV disease, compared with 33% at cancer diagnosis. Prevalent cancer types in the overall cohort included head and neck (15%), thyroid (15%), brain (13%), lung (13%), and colorectal (11%). NTRK1 fusions were most common (45%), followed by NTRK3 (40%) and NTRK2 (15%). Across all lines of therapy, 51% of patients (n = 28) received a TRKi. Among TRKi-treated patients, 71% had stage IV disease at TRKi initiation. The median time from positive NTRK test to initiation of TRKi was 48 days (IQR = 9-207). TRKis were commonly given as first-line (30%) or second-line (48%) therapies. Median duration of therapy was 610 (IQR = 182-764) days for TRKi use and 207.5 (IQR = 42-539) days for all other first-line therapies. CONCLUSIONS: This study reports on contemporary real-world NTRK testing patterns and use of TRKis in solid tumors, including time between NTRK testing and initiation of TRKi therapy and duration of TRKi therapy.

BACKGROUND: Atopic dermatitis (AD), a highly pruritic, inflammatory skin disease, affects approximately 7% of adolescents globally. A topical formulation of ruxolitinib, a Janus kinase (JAK) 1/JAK2 inhibitor, demonstrated safety and efficacy among adolescents/adults in two phase 3 studies (TRuE-AD1/TRuE-AD2). OBJECTIVE: To describe safety and efficacy of 1.5% ruxolitinib cream versus vehicle and long-term disease control of ruxolitinib cream among adolescents aged 12-17 years from pooled phase 3 study data. METHODS: Patients [≥ 12 years old with AD for ≥ 2 years, Investigators Global Assessment score (IGA) 2/3, and 3-20% affected body surface area (BSA) at baseline] were randomized 2:2:1 to ruxolitinib cream (0.75%/1.5%) or vehicle for 8 weeks of continuous use followed by a long-term safety (LTS) period up to 52 weeks with as-needed use. Patients originally applying vehicle were rerandomized 1:1 to 0.75%/1.5% ruxolitinib cream. Efficacy measures at week 8 included IGA treatment success (IGA-TS; i.e., score of 0/1 with ≥ 2 grade improvement from baseline), ≥ 75% improvement in Eczema Area and Severity Index (EASI-75), and ≥ 4-point improvement in itch numerical rating scale (NRS4). Measures of disease control during the LTS period included IGA score of 0 (clear) or 1 (almost clear) and percentage affected BSA. Safety was assessed throughout the study. RESULTS: Of 1249 randomized patients, 245 (19.6%) were aged 12-17 years. Of these, 45 patients were randomized to vehicle and 92 patients to 1.5% ruxolitinib cream. A total of 104/137 (75.9%) patients continued on 1.5% ruxolitinib cream in the LTS period [82/92 (89.1%) continued on 1.5% ruxolitinib cream; 22/45 (48.9%) patients on vehicle were reassigned to 1.5% ruxolitinib cream], and 83/104 (79.8%) of these patients completed the LTS period. At week 8, substantially more patients who applied 1.5% ruxolitinib cream versus vehicle achieved IGA-TS (50.6% versus 14.0%), EASI-75 (60.9% versus 34.9%), and NRS4 (52.1% versus 17.4%; P = 0.009). The mean (SD) reduction in itch NRS scores was significantly greater in patients applying 1.5% ruxolitinib cream versus vehicle from day 2 [- 0.9 (1.9) versus -0.2 (1.4); P = 0.03]. During the LTS period, mean (SD) trough steady-state ruxolitinib plasma concentrations at weeks 12/52 were 27.2 (55.7)/15.5 (31.5) nM. The percentage of patients achieving IGA score of 0 or 1 was sustained or further increased with 1.5% ruxolitinib cream; mean affected BSA was generally low (< 3%; i.e., mild disease). Through 52 weeks, application site reactions occurred in 1.8% of adolescent patients applying 1.5% ruxolitinib cream at any time; no patients had serious adverse events. There were no serious infections, malignancies, major adverse cardiovascular events, or thromboembolic events. CONCLUSIONS: Meaningful anti-inflammatory and antipruritic effects were demonstrated with 1.5% ruxolitinib cream in the subset of adolescent patients with AD, comparable with those observed in the overall study population; long-term, as-needed use maintained disease control and was well tolerated. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT03745638 (registered 19 November 2018) and NCT03745651 (registered 19 November 2018).

First-generation Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been associated with an increased risk of cardiovascular toxicities. Zanubrutinib is a more selective, next-generation BTK inhibitor. In this analysis, incidence rates of atrial fibrillation, symptomatic (grade ≥2) ventricular arrhythmia, and hypertension were evaluated in a pooled analysis of 10 clinical studies with zanubrutinib monotherapy in patients (N = 1550) with B-cell malignancies and a pooled analysis of head-to-head studies comparing zanubrutinib with ibrutinib (ASPEN cohort 1; ALPINE). Among the 10 studies, most patients (median age, 67 years) were male (66.3%) and had CLL/SLL (60.5%). Overall incidence and exposure-adjusted incidence rates (EAIR) for atrial fibrillation, symptomatic ventricular arrhythmia, and hypertension were lower with zanubrutinib than ibrutinib. Despite a similar prevalence of preexisting cardiovascular events in ASPEN and ALPINE, atrial fibrillation/flutter incidence rates (6.1% vs 15.6%) and EAIR (0.2 vs 0.64 persons per 100 person-months; P < .0001) were lower with zanubrutinib than with ibrutinib. Symptomatic ventricular arrhythmia incidence was low for both zanubrutinib (0.7%) and ibrutinib (1.7%) with numerically lower EAIR (0.02 vs 0.06 persons per 100 person-months, respectively) for zanubrutinib. The hypertension EAIR was lower with zanubrutinib than ibrutinib in ASPEN but similar between treatment arms in ALPINE. The higher hypertension EAIR in ALPINE was inconsistent with other zanubrutinib studies. However, fewer discontinuations (1 vs 14) and deaths (0 vs 6) due to cardiac disorders occurred with zanubrutinib versus ibrutinib in ALPINE. These data support zanubrutinib as a treatment option with improved cardiovascular tolerability compared with ibrutinib for patients with B-cell malignancies in need of BTK inhibitors. These trials were registered at www.ClinicalTrials.gov as # NCT03053440, NCT03336333, NCT03734016, NCT04170283, NCT03206918, NCT03206970, NCT03332173, NCT03846427, NCT02343120, and NCT03189524.

N-myristoyltransferase (NMT) is a promising antimalarial drug target. Despite biochemical similarities between Plasmodium vivax and human NMTs, our recent research demonstrated that high selectivity is achievable. Herein, we report PvNMT-inhibiting compounds aimed at identifying novel mechanisms of selectivity. Various functional groups are appended to a pyrazole moiety in the inhibitor to target a pocket formed beneath the peptide binding cleft. The inhibitor core group polarity, lipophilicity, and size are also varied to probe the water structure near a channel. Selectivity index values range from 0.8 to 125.3. Cocrystal structures of two selective compounds, determined at 1.97 and 2.43 Å, show that extensions bind the targeted pocket but with different stabilities. A bulky naphthalene moiety introduced into the core binds next to instead of displacing protein-bound waters, causing a shift in the inhibitor position and expanding the binding site. Our structure-activity data provide a conceptual foundation for guiding future inhibitor optimizations.

BACKGROUND: This post-hoc retrospective study describes long-term patient-reported outcomes (PROs) for REarranged during Transfection (RET)-altered non-small-cell lung cancer (NSCLC), medullary thyroid cancer (MTC), non-MTC thyroid cancer (TC), and tumor agnostic (TA) patients (Data cut-off: January 2023) from the LIBRETTO-001 trial. PATIENTS AND METHODS: Patients completed the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Core 30 (QLQ-C30). Patients with MTC also completed a modified version of the Systemic Therapy-Induced Diarrhea Assessment Tool (mSTIDAT). The proportion of patients with improved, stable, or worsened status after baseline was reported. PROs were summarized at 3 years (cycle 37) post-baseline for the NSCLC and MTC cohorts, and at 2 years (cycle 25) post-baseline for the TC and TA cohorts. Time-to-event outcomes (time to first improvement or worsening and duration of improvement) were reported. RESULTS: The baseline assessment was completed by 200 (63.3%), 209 (70.8%), 50 (76.9%), and 38 (73.1%) patients in the NSCLC, MTC, TC, and TA cohorts, respectively. The total compliance rate was 80%, 82%, 70%, and 85%, respectively. Approximately 75% (NSCLC), 81% (MTC), 75% (TC), and 40% (TA) of patients across all cohorts reported improved or stable QLQ-C30 scores at year 3 (NSCLC and MTC) or year 2 (TC and TA) with continuous selpercatinib use. Across cohorts, the median time to first improvement ranged from 2.0 to 19.4 months, the median duration of improvement ranged from 1.9 to 28.2 months, and the median time to first worsening ranged from 5.6 to 44.2 months. The total compliance rate for the mSTIDAT was 83.7% and the proportion of patients with MTC who reported diarrhea on the mSTIDAT was reduced from 80.8% at baseline to 35.6% at year 3. CONCLUSIONS: A majority of patients with RET-driven cancers improved or remained stable on most QLQ-C30 domains, demonstrating favorable health-related quality of life as measured by the QLQ-C30 during long-term treatment with selpercatinib.

Ruxolitinib reduces spleen volume, improves symptoms, and increases survival in patients with intermediate- or high-risk myelofibrosis. However, suboptimal response may occur, potentially because of signaling via the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway. This phase 2 study evaluated dosing, efficacy, and safety of add-on PI3Kδ inhibitor parsaclisib for patients with primary or secondary myelofibrosis with suboptimal response to ruxolitinib. Eligible patients remained on a stable ruxolitinib dose and received add-on parsaclisib 10 or 20 mg, once daily for 8 weeks, and once weekly thereafter (daily-to-weekly dosing; n = 32); or parsaclisib 5 or 20 mg, once daily for 8 weeks, then 5 mg once daily thereafter (all-daily dosing; n = 42). Proportion of patients achieving a ≥10% decrease in spleen volume at 12 weeks was 28% for daily-to-weekly dosing and 59.5% for all-daily dosing. Proportions of patients achieving ≥50% decrease at week 12 in Myelofibrosis Symptom Assessment Form and Myeloproliferative Neoplasms Symptom Assessment Form symptom scores were 14% and 18% for daily-to-weekly dosing, and 28% and 32% for all-daily dosing, respectively. Most common nonhematologic treatment-emergent adverse events were nausea (23%), diarrhea (22%), abdominal pain and fatigue (each 19%), and cough and dyspnea (each 18%). New-onset grade 3 and 4 thrombocytopenia were observed in 19% of patients, each dosed daily-to-weekly, and in 26% and 7% of patients dosed all-daily, respectively, managed with dose interruptions. Hemoglobin levels remained steady. The addition of parsaclisib to stable-dose ruxolitinib can reduce splenomegaly and improve symptoms, with manageable toxicity in patients with myelofibrosis with suboptimal response to ruxolitinib. This trial was registered at www.clinicaltrials.gov as #NCT02718300.

A highly convenient and straightforward strategy for the synthesis of difluoromethyl substituted tricyclic fused chromono[3,2- c ]pyrazolines/pyrazoles is developed via [3+2]-cycloaddition of difluoroacetohydrazonoyl bromides to chromene derivatives bearing an electron-withdrawing group at the 3-position. The reaction has the advantages of mild conditions, good tolerance of functional groups, and simple operation. [ABSTRACT FROM AUTHOR]

The catalytic asymmetric electrophilic functionalization of the less reactive N-heteroaromatic compounds has been reported using the approach of the introduction of an exocyclic amino substituent. This strategy has allowed enantioselective Friedel–Crafts alkylation in pyrazoles, isoxazoles and isothiazoles, as well as in aminoindoles, aminobenzofurans and aminobenzothiophenes. Several stereoselective methods have been used for the 1,4-addition or 1,2-addition of these heteroaromatic compounds to different electrophiles employing organocatalysts or chiral metal complexes. The activating exocyclic amino substituent has also been used as a nucleophile in tandem reactions, including formal cycloadditions ([3+2] and [3+3]), for the synthesis of highly functionalized chiral nitrogen heterocycles. [ABSTRACT FROM AUTHOR]

We recently demonstrated that suitably functionalised aryliminopyrazoles can exhibit useful photoswitching properties. This study investigates the photoswitching potential of iminobispyrazoles (IBPs). We find that the regiochemistry of the IBPs strongly dictates their photoswitching properties, most notably, the λmax, the photostationary state, and the thermal half-life of the Z-isomer. [ABSTRACT FROM AUTHOR]

A facile synthetic routes to access some new heterocyclic systems containing potent pharmacophoric groups such as pyrazole, pyrazolo[5,1-c]-1,2,4-triazine, 1,2,4-triazino[4,3-a]benzimidazole, and pyridine moieties linked to pyridine-carboxamide moiety are reported. Construction of the target compounds was achieved via reaction of 3-oxo-butanamides 1a,b with hydrazonoyl halides, heterocyclic diazonium salts, and malononitrile derivatives, respectively. The structures of the new products were confirmed by all possible spectral and elemental analyses. The antibacterial assessment showed that one product was moderately active against both K. pneumonia and S. aureus. [ABSTRACT FROM AUTHOR]

The construction of C−N bond at the α‐position of BODIPYs (boron dipyrromethene) not only enables flexible reactivity but also leads to strong electron‐donating properties. In this study, a base‐promoted oxidative cross‐dehydrogenative coupling was developed to synthesize α‐amino BODIPYs with air as a green oxidant. By this strategy, a series of weak nitrogen nucleophiles, such as heteroaryl and aryl anilines, were installed to the α‐position. Remarkably, pyrrole, pyrazole and indole were also employed to realize the synthesis of α‐heteroaryl BODIPYs through direct functionalization. Further aggregation‐induced emission enhancement (AIE) properties and lipid droplet‐targeting bioimaging experiments of representative dyes demonstrated their potential applications as organic probes. [ABSTRACT FROM AUTHOR]

By treatment of the peracetylated methylester of 4-acetylamino-2,4-dideoxy-d-glycero-d-galacto-octonic acid (ADOA-PAE) with nitrosyl tetrafluoroborate, a serendipitous formation of a highly functionalized carbohydrate–pyrazole conjugate was observed in 95% yield. This observation is remarkable, as it involves a five-step one-pot synthesis that proceeds via an 1,3-acyl shift and a 1,5-electrocyclization, which usually requires thermal conditions; however, the reaction occurred at a temperature of 0 °C. Additionally, the excellent yield of the carbohydrate-decorated pyrazole and the regiospecificity of the cyclization are of particular interest, as regioselectivity is always a challenge in pyrazole synthesis. Subsequently, this novel access to pyrazoles starting from N-acetyl-allyl amides via nitrosation and electrocyclization was investigated. In addition, mechanistic studies for the formation of substituted pyrazoles of type were carried out. [ABSTRACT FROM AUTHOR]

Breaking aromaticity by inserting additional atoms within the skeleton of heteroaromatic rings has gained significant attention over the years. As part of the emerging concept of 'skeletal editing', this short review retraces the recent progress made on dearomative enlargement reactions of both five- and six-membered heterocycles. 1 Introduction 2 Dearomative Enlargement of Five-Membered Rings 2.1 Pyrroles, Furans, Thiophenes and Their Fused Analogues 2.2 Pyrazoles, Isoxazoles, Isothiazoles and Their Fused Analogues 3 Dearomative Enlargement of Six-Membered Rings 4 Conclusion and Perspectives [ABSTRACT FROM AUTHOR]

Pyrazole is an omnipresent moiety in many natural products and pharmaceutically active compounds. Here, we have developed a simple and dynamic method for one‐pot synthesis of substituted pyrazoles through the intramolecular cyclization of hydrazides and alkynyl ketones, using a novel sulfonium saltbased iodate (І) reagent system. This method has the advantage that it proceeds in a one‐pot, without isolating a less stable hydrazone intermediate. Hypervalent iodine‐based reagents are an environmentally benign and greener option to toxic metal oxidants; they have an extensive application in metal‐catalyst‐free reactions, and this reaction proceeds in less time with high yields. [ABSTRACT FROM AUTHOR]

In this work, a series of pyrazole‐linked 1,2,4‐triazole‐3‐thiol derivatives (3a–i) were prepared and identified by 13C NMR, 1H NMR, and mass spectrometry (ESI‐MS) data. The newly synthesized molecules were also evaluated in vitro for their α‐amylase and α‐glucosidase inhibitory potential. All newly synthesized compounds exhibited potent α‐glucosidase inhibition activity with IC50 in the range of 1.016 ± 0.70 to 24.40 ± 0.02 µM and good α‐amylase inhibitory with IC50 in the range of 49.91 ± 0.32 to 500 µM, as compared to acarbose. The most potent compound among this series is derivative 3e, with IC50 value of 1.016 ± 0.70 µM, which is many folds more than that of acarbose. In addition, in docking studies, both compounds exhibited good interactions at the active region of target proteins. Therefore, this study may lead via structural modifications to the discovery of new potent α‐amylase and α‐glucosidase inhibitors useful in the diabetes treatment. [ABSTRACT FROM AUTHOR]

We report the design, synthesis, photoswitching and computational studies of N-methyl arylazo-3,5-(di-2-pyridyl)pyrazole and its N-alkyl pyridinium derivatives with an ionic center proximally located to the azo group. Besides achieving excellent photoswitching characteristics, particularly at longer wavelengths, and tuning Z isomer stability due to the effects of counter ions and pH, the utility of neutral and ionic photoswitches for pH modulation by light was achieved. [ABSTRACT FROM AUTHOR]

Objective: In the present work synthesis and characterization of new heterocyclic derivatives containing dihydropyrano[2,3-c]pyrazoles. Methods: Synthesis of compounds was done using the conventional method via multicomponent reaction using substituted aldehyde, hydrazine hydrate or phenyl hydrazine, malononitrile, and L-proline as a catalyst with good yield. Reaction optimization is also performed. Results and Discussion: All synthesized compounds were tested for their in vitro anti-inflammatory and a comparison was done against the standard drug Diclofenac sodium. Conclusions: Some of the newly synthesized compounds demonstrated good to moderate anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

ABSTRACT Pyrazole derivatives are strategic structural motifs due to their proven utility in preparing chemicals in biological, pharmaceutical, photophysical, technological, and industrial fields; therefore, syntheses of pyrazole‐containing compounds are highly desirable. Some nitrogen‐rich pyrazoles, specifically nitrated derivatives posing high density and moderate thermal stability, have been used as energetic compounds since a high amount of energy is stored in their structures that can be released quickly with high detonation power under external stimuli (i.e., thermal, impact, and friction). These compounds have good capacity and sensitivity in explosives, propellants, and pyrotechnics applications in eco‐friendly ways. Therefore, this contribution focuses on recent and illustrative examples regarding the (i) synthesis and reactivity of pyrazoles, especially works of the last decade, highlighting works on (ii) applications in energetic compounds to analyze their scope. [ABSTRACT FROM AUTHOR]

Pyrazoles and pyrazolo fused pyrimidines and pyridines are well known for their applications in various fields like pharmaceuticals, agrochemicals and materials sciences. Keeping this in mind herein, we have developed the transition‐metal‐free approach for the chemo‐selective synthesis of the pyrazole and its derivatives from acetopheneones. The selectivity of the reaction can easily be tuned by shifting reaction from acidic to basic medium for the synthesis of pyrazolo‐pyrirmidines and pyrazolo‐pyridines respectively. The reaction shows excellent functional group tolerance in the form of −F, −Cl, −Br, −NMe2, −OH, −OMe, and −B(OH)2 in good yields. [ABSTRACT FROM AUTHOR]

The metal-free direct oxidative cross-dehydrogenative C–H bond amination of imidazopyridines with pyrazole in water as solvent has been developed under K2 S2 O8-promoted mild conditions. This strategy was applied to variable imidazoheterocycles to give amination products in moderate to good yields. The described protocol also offers scale-up synthesis for the construction of C–N bonds, which makes it suitable for the synthesis of biologically active compounds and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Herein, we have developed a metal‐free, atom‐economical, intrinsically sustainable approach for synthesizing unprotected 4,5‐diamino pyrazoles from readily available 1,2‐diaza‐1,3‐dienes. This approach utilizes inexpensive hydrazine hydrate as the aminating source. Further, we have explored the reactivity of 4,5‐diamino pyrazole to synthesize fused pyrazolo[3,4‐d]‐1,2,3‐triazole heterocyclic compounds. We have also successfully demonstrated the synthetic utility of this methodology in synthesizing two drug analogs: analgesic difenamizole and anti‐psychotic CDPPB. The role of the phenyl ring of 3‐substituted‐1,2‐diaza‐1,3‐diene was explained with the help of control experimental and density functional theory (DFT) computation studies. [ABSTRACT FROM AUTHOR]

ABSTRACT For the first time, the interaction of perfluoro‐1,4‐naphthoquinone with various 5‐aminopyrazoles was investigated. It was shown that three types of products can be obtained depending on the structure of starting aminopyrazole. For all examples, the substitution of one fluorine atom in quinone moiety was observed. Wherein, in most cases, the starting aminopyrazoles act as a C‐nucleophile leading to 2‐(5‐aminopyrazol‐4‐yl)‐3,5,6,7,8‐pentafluoronaphthalene‐1,4‐diones. At the same time substrates unsubstituted at ring nitrogen atom regiospecifically react at aminogroup resulting in the formation of 2,5,6,7,8‐pentafluoro‐3‐((pyrazol‐5‐yl)amino)naphthalene‐1,4‐diones. Besides that, the absence of steric hindrance in the pyrazole unit allowed us to direct the process at nitrogen atom in Position 2 and synthesize zwitter‐ionic 3‐(5‐aminopyrazol‐2‐ium‐2‐yl)‐5,6,7,8‐tetrafluoro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐olates. The structures of two types of obtained products were confirmed by x‐ray analysis. [ABSTRACT FROM AUTHOR]

Over the last three decades, owing to labour cost, time and especially environmental issues, one‐pot synthesis of heterocyclic compounds involving tandem or multicomponent (sequential or consecutive) reactions has gained particular attention worldwide. Most of the marketed drug molecules hold one or more heterocyclic rings. Due to some side effects of several drugs along with the gradual emergence of antimicrobial resistance, the necessity for developing new heterocyclic molecules continues; special attention should be paid in this respect towards employing more one‐pot reactions for their syntheses. Pyrazolopyridines are fused heterocycles holding pyridine and pyrazole and possess a wide variety of biological and pharmaceutical properties. Several existing drug molecules also bear pyrazolopyridine scaffolds. The present perspective is an endeavour to encompass green syntheses of different isomeric pyrazolopyridine systems, most of these published during the past five years or more for a few cases. [ABSTRACT FROM AUTHOR]

ABSTRACT Imidazole is one of the most important heterocyclic rings. This nucleus can be found in a plethora of substances in different knowledge areas such as medicinal, agrochemical, polymer, and dyestuff. N‐alkylation reactions involving N − 1 atom is a remarkable tool to synthesize many imidazole derivatives which can be attached to a great variety of functional groups. In this work, we synthesized 10 new intermediates 4‐chlorobutyl 1‐aryl‐1H‐pyrazole‐4‐carboxylates 3(a–j) from 1‐aryl‐1H‐pyrazole‐4‐carbonyl chlorides, obtained from 1‐aryl‐1H‐pyrazole‐4‐carboxylic acids 4(a–j), and 4‐chlorobutan‐1‐ol 1, generated by THF ring‐opening promoted by hydrochloric acid. Compounds 3(a–j) promoted N‐alkylation of 4(5)‐nitro‐1H‐imidazole to afford the targets 4‐(4‐nitro‐1H‐imidazol‐1‐yl)butyl 1‐aryl‐1H‐pyrazole‐4‐carboxylates 2(a–j) in 18%–85% yields. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Herein, an unprecedented nickel‐catalyzed regioselective hydroalkynylation of unsymmetrical internal alkynes was realized with steric hindered resistance selectivity via the cyano‐directing group strategy. Significantly, the resulting 1,3‐enyne products could be effectively employed in the synthesis of novel nitrogen‐containing tricyclics compounds, that provided the potential candidate compound 8a (IC50 = 2.6—6.1 μmol/L) for the anti‐tumor cell proliferation activity. Therefore, this work not only improves the transition‐metal‐ catalyzed hydroalkynylation strategy of internal alkynes, but also exhibits versatility of 1,3‐enynes in the construction of the complex bioactive chemical space. [ABSTRACT FROM AUTHOR]

A wide range of α-aryl-α-diazophosphonates were easily prepared via modified diazo transfer reaction. Benzylphoshonates reacted with tosyl azide (TsN3) in the presence of potassium tert -butoxide (KO t Bu) to afford diazophosphonates in yields up to 93% (generally 70–80%). Aryldiazophosponates were successfully explored for the synthesis of 5-aryl-substituted pyrazol-3-carboxylates in one pot by the 1,3-dipolar cycloaddition with alkyl acrylates followed by NaH treatment. The second stage led to elimination of the diethoxylphosphoryl moiety with the aromatization of cycle. [ABSTRACT FROM AUTHOR]

The condensation of 1,3‐diketones with hydrazine to access 4H‐pyrazoles is a well‐established synthetic route that travels through a 4H‐pyrazol‐1‐ium intermediate. In the route to a 3,5‐diphenyl‐4H‐pyrazole containing a cyclobutane spirocycle, density functional theory calculations predict, and experiments show that the protonated intermediate undergoes a rapid 1,5‐sigmatropic shift to form a tetrahydrocyclopenta[c]pyrazole. Replacing the 3,5‐diphenyl groups with 2‐furanyl groups decreases the calculated rate of the 1,5‐sigmatropic shift by 6.2 × 105‐fold and enables the isolation of new spirocyclic 4H‐pyrazoles for click chemistry. [ABSTRACT FROM AUTHOR]

A novel Rh‐catalyzed three‐component synthesis of N‐(o‐alkylaryl) pyrazoles via cascade pyrazole annulation and aryl C‐H conjugate addition to alkenes has been developed with enaminones, hydrazines, and functionalized alkenes as starting materials. The raw materials used in this reaction are simple, cheap, and readily available, and the reactions feature excellent step economy by furnishing products via the formation of a pyrazole ring and a key C‐H activation in one‐step operation. Moreover, the reaction proceeds smoothly under air atmosphere, making it easy to operate. [ABSTRACT FROM AUTHOR]

The in vitro antifungal, antibacterial, and antioxidant activities of a substituted pyrazole derivative (FHM) have been evaluated in the current work. The addition of 4-methylpiperidin-4-ol, which increases the molecule's lipid solubility and speeds up absorption by increasing its rate of absorption, gives the molecule strong in vitro antifungal and antibacterial properties. Additionally, it is clear from the findings of structure-activity relationship (SAR) investigations. Additionally, the ab-intio technique was used to theoretically evaluate the photophysical characteristics of produced substances. Using the DFT-B3LYP-6-31G(d) basis set, the ground state optimization and HOMO-LUMO energy levels are computed. Global chemical reactivity and descriptive characteristics are evaluated using theoretically estimated HOMO-LUMO values, and the results demonstrate that the synthesized molecule possesses a high electrophilicity and electronegative index. Overall findings indicate that substituting a 4-methylpiperidin-4-ol substituted pyrazole derivative shows good photophysical and in vitro biological applications. [ABSTRACT FROM AUTHOR]

The regioselective synthesis of 1‐alkyl‐5‐arylpyrazoles, which are potential drug candidates, has been difficult to achieve thus far. In this study, we developed an auto‐tandem Pd‐catalyzed C−C bond cleavage/Heck arylation of N‐cyclopropylhydrazones followed by cycloisomerization to afford diverse 1‐alkyl‐5‐arylpyrazoles. This step‐economical synthesis involves the cleavage of two C−H bonds and one C−C bond as well as the incorporation of directing groups. The identification of the reaction intermediates indicated an auto‐tandem catalytic pathway. The further transformation of products to 1,4,5‐substituted pyrazole and functional group transformations were carried out. [ABSTRACT FROM AUTHOR]

The enantioselective 1,4-addition reaction of pyrazolin-5-ones to α,β-unsaturated ketones catalyzed by a cinchona alkaloid-derived primary amine–Brønsted acid composite is reported. Both enantiomers of the anticipated pyrazole derivatives were obtained in good to excellent yields (up to 97%) and high enantioselectivities (up to 98.5% ee) under mild reaction conditions. In addition, this protocol was further expanded to synthesize highly enantioenriched hybrid molecules bearing biologically relevant heterocycles.

A series of 4-thio/seleno-cyanated pyrazoles was conveniently synthesized from 4-unsubstituted pyrazoles using NH4SCN/KSeCN as thio/selenocyanogen sources and PhICl2 as the hypervalent iodine oxidant. This metal-free approach was postulated to involve the in situ generation of reactive thio/selenocyanogen chloride (Cl–SCN/SeCN) from the reaction of PhICl2 and NH4SCN/KSeCN, followed by an electrophilic thio/selenocyanation of the pyrazole skeleton.

The escalating incidence of bacterial resistance to commonly prescribed antibiotics underscores the urgent need for the rapid development of innovative antibacterial medications. Heterocyclic compounds, particularly nitrogen‐containing heterocycles like pyrazoles and thiazoles, have garnered attention for their diverse biological activities, including antimicrobial properties. Here, we present a green and efficient multicomponent synthesis method for fourteen novel benzothiazole‐tethered pyrazole derivatives. Utilizing the deep eutectic solvent glycerol/K2CO3 as a base‐catalytic reaction medium at 70 °C, this synthesis approach yielded promising compounds exhibiting substantial antimicrobial activity against various pathogenic microorganisms such as Staphylococcus aureus, Bacillus cereus, and Candida albicans. Among these, 4‐(benzo[d]thiazol‐2‐yl)‐3‐(4‐nitrophenyl)‐1‐phenyl‐1H‐pyrazol‐5‐amine emerged as the most promising candidate, showcasing significant inhibitory potentials with CZD values of 24 mm, 21 mm, and 26 mm for S. aureus, B. cereus, and C. albicans, respectively. Molecular docking studies further supported the experimental observations, revealing the high binding affinity of the compound to the nitroreductase enzyme with a binding score of −8.5 kcal/mol. These findings underscore the potential of these synthesized compounds as antimicrobial agents and suggest avenues for future research in exploring their structure‐activity relationships and therapeutic applications in combating bacterial infections. [ABSTRACT FROM AUTHOR]

We studied the reaction of N‐alkyl(aryl)pyrazoles with silylformamidine 1 that exists in an equilibrium with its carbene form via migration of the trimethylsilyl group from the carbon to nitrogen atom. The carbene insertion proceeded at the C−H group in 5th position. N‐alkyl(aryl)pyrazoles featuring substituents such as Br, CN and NO2 group reacted readily affording the corresponding aminals. This approach allowed us to synthesize pyrazole dialdehyde and phosphine featuring a vicinal aldehyde group. The reaction does not require any catalyst. The insertion position was unambiguously confirmed by X‐ray analysis of an aminal and a set of derivatives. Aminals hydrolysis afforded the corresponding pyrazole carbaldehydes. Methanolysis of the aminals gave N‐methylimines of the pyrazolecarbaldehydes. Highly acidic nitro pyrazole instead of the insertion underwent silylation in 5th position. [ABSTRACT FROM AUTHOR]

This manuscript reports a novel method for the direct iodination of the C‐4 pyrazole ring generated in situ by the reaction of 1,1,3,3‐tetramethoxypropane and various hydrazines. In this approach, potassium iodate (KIO3) is used as the iodinating agent and (PhSe)2 is used as catalysts under acidic conditions. This protocol provides a convenient method for the efficient synthesis of 4‐iodo‐1‐aryl‐1H‐pyrazoles, valuable intermediates for several different coupling reactions. [ABSTRACT FROM AUTHOR]

Chemical reactivity and applications of 4-alkynylated pyrazol-3-ones are described. A facile access to the synthesis of novel pyrazol-4-yl furan- and/or thiophene-2-carboxylates through the ring transformation and subsequent acylation of 4-alkynylated pyrazol-3-ones as the key intermediates, which were prepared from pyrazole-4,5-dione and terminal alkynes, in moderate to good yields is achieved. All the synthesized compounds were characterized by spectroscopic analysis. [ABSTRACT FROM AUTHOR]

The very limited number of structurally known thionitrosyl complexes of technetium was increased by the synthesis of [TcII(NS)Cl3(PPh3)2] (3) and [TcII(NS)Cl3(PPh3)(OPPh3)] (4) and their reaction products with hydrotris(pyrazolyl)borates, {HB(pzR)3}−. Similar reactions were conducted with [TcI(NO)Cl2(PPh3)2(CH3CN)] and related rhenium thionitrosyls. Remarkably, most such reactions result in a rapid cleavage of the boron–nitrogen bonds of the ligands and the formation of pyrazole complexes of the two group 7 metals. Only one compound with an intact {HB(pzR)3}− ligand could be isolated: the technetium(I) complex [TcI(NO)Cl(PPh3){HB(pz)3}] (2). Other products show the coordination of one or four neutral pyrazole ligand(s) in the coordination spheres of technetium generated by thermal decomposition of the pyrazolylborates [TcI(NO)Cl2(PPh3)2(pzH)] (1) and [TcI(NS)Cl(pzHMe2)4]+ (5). Reactions with the corresponding thionitrosylrhenium complex [ReII(NS)Cl3(PPh3)2] require higher temperatures and only compounds with one pyrazole ligand, [ReI(NS)Cl2(PPh3)(pzHR)] (6a–6c), were isolated. The products were studied spectroscopically and by X-ray diffraction. [ABSTRACT FROM AUTHOR]

In this study, the magnetic Mg0.5Zn0.375Ni0.125Fe2O4 nanoparticle was prepared by the co-precipitation method and characterized with various methods, such as FT-IR, XRD, TGA, FESEM, EDX, and VSM. The catalytic activity of this magnetic nanocatalyst was perused in synthesizing dihydropyrano[2,3-c] pyrazole and tetrahydrodipyrazolopyridines derivatives. To indicate some of this paper's preponderances, preparing a novel heterogeneous magnetic nanocatalyst with high reactivity produces high-yield and purity products. Moreover, the synthesized nanocatalyst has advantages such as high catalytic activity, non-toxicity, short reaction time, easy separation from the reaction mixture using an external magnet, and reusability several times without significant loss in its catalytic activity. [ABSTRACT FROM AUTHOR]

The reactivity of imidazole, pyrazole, 1,2,4‐triazole, 1,2,3‐triazole, and tetrazole with acetone (propan‐2‐one) has been studied by 1H and 13C NMR using acetone‐d6 as solvent at temperatures ranging from 173 to 300 K at 10 K intervals. Simultaneously, the reaction has been theoretically calculated at the B3LYP/6‐311++G(d,p) level, and experimental and theoretical results have been compared. The equilibrium constants between azoles and adducts α,α‐dimethyl‐azole‐methanol were analyzed, assuming that the straight part of the plots –R ln Ke vs. 1/T can be used to determine ΔH and ΔS. Calculated and experimental data are related, but the theoretical values are proportionally higher. The tautomerism of triazoles and tetrazole has been considered in order to discuss the reactions. [ABSTRACT FROM AUTHOR]

In order to obtain acaricides of pyrazole acrylonitrile with better acaricidal activity for mitecontrol, seventeen novel ester derivatives were synthesized via four steps of Blanc chloromethylation reaction, dehalogenation reaction, condensation reaction and esterification reaction using ethyl 1,3-dimethyl-1H-pyrazole-5-carboxylate as the starting material. Furthermore, their acaricidal activity against Tetranychus cinnabarinus was assessed by immersion test, and the mortality rate and lethal midrange concentration LC50 were calculated. The results show that the target compounds display excellent acaricidal activity against T. cinnabarinus, and compared with the commercial pesticide cyenopyrafen (LC50 = 0.61 mg/L), compounds 5q and 5k possess significantly higher acaricidal activity against T. cinnabarinus with LC50 values of 0.17 and 0.22 mg/L, respectively. [ABSTRACT FROM AUTHOR]

In this Communication, we comprehensively investigated substituent effects relevant to iterative reversible activation fragmentation chain transfer (RAFT) single unit monomer insertion (SUMI) reactions. Through the use of the pyrazole carbodithiolate (PCDT) "Z-group" as the chain transfer component in RAFT SUMI, we show the importance of "Z-group" effects and its interplay with "R-group" (the carbon-centred radical precursor) effects. We also expanded the scope of RAFT SUMI to new monomer types and sequences thereof. As such, the C–S bond dissocation/reformation steps were found to be crucial factors in SUMI, and it was found that general substituent effects must be wholistically examined for every step of this reaction. This stands in contrast with conventional knowledge of RAFT polymerisation, where the main consideration is often centred around the propagation stage, i.e., the key C–C bond formation step. Indeed, contrary to SUMI, the latter characteristic was observed in the analogous alternating copolymerisation. [ABSTRACT FROM AUTHOR]

We report an efficient [3+2] cycloaddition protocol for the synthesis of pyrazolo[1,2‐a]pyrazolones from Morita‐Baylis‐Hillman adducts and N,N'‐cyclic azomethine imines. The R‐BINOL chiral phosphoric acid was identified as the suitable catalyst for the reported cycloaddition protocol. Almost all MBH adducts regioselectively delivered 7‐oxo‐pyrazolo[1,2‐a]pyrazoles at an efficient yield of 69–91 %. With exception, the MBH adducts derived from acrylonitrile deliver 5‐oxo‐pyrazolo[1,2‐a]pyrazoles comparatively at a higher yield than the 7‐oxo‐pyrazolo[1,2‐a]pyrazoles. The density functional theory (DFT) studies demonstrate that the reaction is thermodynamically more feasible in the presence of R‐BINOL chiral phosphoric acid. [ABSTRACT FROM AUTHOR]

Precise modification of a chemical site in a molecule at the single-atom level is one of the most elegant yet difficult transformations in chemistry. A reagent specifically designed for chemoselective introduction of monoatomic carbon is a particularly formidable challenge. Here, we report a straightforward, azide-free synthesis of a crystalline and isolable diazophosphorus ylide, Ph3PCN2, a stable compound with a carbon atom bonded to two chemically labile groups, triphenylphosphine (PPh3) and dinitrogen (N2). Without any additives, the diazophosphorus ylide serves as a highly selective transfer reagent for fragments, including Ph3PC, to deliver phosphorus ylide–terminated heterocumulenes and CN2 to produce multisubstituted pyrazoles. Ultimately, even exclusive carbon-atom transfer is possible. In reactions with aldehydes and acyclic and cyclic ketones (R2C=O), the carbon-atom substitution forms a vinylidene (R2C=C:) en route to alkynes or butatrienes. [ABSTRACT FROM AUTHOR]

Novel library of pyrazole derivatives (6a–k) from substituted 4-dioxaborolanyl-1H-pyrazole and halo benzaldehyde through simultaneous Suzuki reaction, nucleophilic addition, and hydrolysis under moderate reaction conditions. The desired compounds 6a–k have been formed in good to high yield. All the compound structures were characterized by analytical and spectral (1H NMR,13C NMR and MS) studies. Furthermore, the evaluation of biological activity of synthesized molecules. [ABSTRACT FROM AUTHOR]

Novel fluorescent pyrazole-containing boron (III) complexes were synthesized employing a one-pot three-component reaction of 3-hydroxy-1-phenyl-1H-pyrazole-4-carbaldehyde, 2-aminobenzenecarboxylic acids, and boronic acids. The structures of the novel heterocyclic compounds were confirmed using 1H-, 13C-, 15N-, 19F-, and 11B-NMR, IR spectroscopy, HRMS, and single-crystal X-ray diffraction data. The photophysical properties of the obtained iminoboronates were investigated using spectroscopic techniques, such as UV–vis and fluorescence spectroscopies. Compounds display main UV–vis absorption maxima in the blue region, and fluorescence emission maxima are observed in the green region of the visible spectrum. It was revealed that compounds exhibit fluorescence quantum yield up to 4.3% in different solvents and demonstrate an aggregation-induced emission enhancement effect in mixed THF–water solutions. [ABSTRACT FROM AUTHOR]

An electrochemical protocol for synthesizing tetra‐substituted sulfonated pyrazoles is developed. The notable feature of this method is the electrocatalytic generation of an active iodine species, which enables the direct use of 1,3 dicarbonyls as the reactant and also eliminates the necessity for external electrolytes. A wide range of functionalities are compatible under the electrocatalytic condition, resulting good to excellent production of the desired pyrazole derivatives. Detailed synthetic and electrochemical studies enlighten the electrocatalytic pathway. [ABSTRACT FROM AUTHOR]

Inspired by the enzyme acetylene hydratase, we investigated the reactivity of acetylene with tungsten(II) pyrazole complexes. Our research revealed that the complex [WBr2(pz-NHCCH3)(CO)3] (pz = 3,5-dimethyl-pyrazolate) facilitates the stochiometric reaction between pzH and acetylene to give N-vinyl-pz. This vinyl compound readily hydrolyzes to acetaldehyde, mirroring the product of acetylene hydration in the enzymatic process. The formation of the vinyl compound likely involves a reactive intermediate complex where acetylene acts as a two-electron donor, in contrast to isolable acetylene complexes that are inert to nucleophilic attack by water. Results suggest an alternative mechanism for the enzyme, including vinylation of a neighboring amino acid by acetylene in the active site prior to hydration. [ABSTRACT FROM AUTHOR]

An efficient palladium‐catalyzed three‐component reaction for the synthesis of tricyclic fused 1,2,3‐triazole derivatives from amino‐NH‐1,2,3‐triazoles, isocyanide and iodoarenes has been developed, involving three new bonds formation by one manipulation in moderate to good yields with excellent functional group tolerance. Moreover, it is also suitable for other N‐heterocyclic substrates including pyrazole, imidazole, indole, tetrazole and its derivatives. [ABSTRACT FROM AUTHOR]