• 1. Fe(iii)-mediated isomerization of α,α-diarylallylic alcohols to ketones via radical 1,2-aryl migration?
  Ziyang Deng,Changwei Chen,Sunliang Cui RSC Adv., 2016,6, 93753-93755
• 2. Evidence of field induced slow magnetic relaxation in cis-[Co(hfac)2(H2O)2] exhibiting tri-axial anisotropy with a negative axial component?
  Denis V. Korchagin,Elena A. Yureva,Alexander V. Akimov,Eugenii Ya. Misochko,Gennady V. Shilov,Artem D. Talantsev,Roman B. Morgunov,Alexander A. Shakin,Sergey M. Aldoshin,Boris S. Tsukerblat Dalton Trans., 2017,46, 7540-7548
• 3. Enantio- & chemo-selective preparation of enantiomerically enriched aliphatic nitro alcohols using Candida parapsilosis ATCC 7330
  Sowmyalakshmi Venkataraman RSC Adv., 2015,5, 73807-73813
• 4. Fe/Fe3C@C nanoparticles encapsulated in N-doped graphene–CNTs framework as an efficient bifunctional oxygen electrocatalyst for robust rechargeable Zn–air batteries?
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• 5. Excellent energy storage performance in NaNbO3-based relaxor antiferroeic ceramics under a low electric field
  XuxinCheng,XiaomingChen,PengyuanFan

• Solvents and Organic Chemicals Organic Compounds Hydrocarbons Saturated hydrocarbons Alkanes

3-Ethynyl-1H-indazole (CAS 1383705-71-2): A Versatile Building Block in Medicinal Chemistry and Drug Discovery

In the dynamic field of medicinal chemistry, 3-Ethynyl-1H-indazole (CAS 1383705-71-2) has emerged as a crucial heterocyclic compound with significant potential in pharmaceutical research and drug development. This indazole derivative, characterized by its unique ethynyl functional group, serves as a valuable chemical building block for synthesizing more complex molecules with potential therapeutic applications.

The growing interest in 3-Ethynyl-1H-indazole stems from its versatile chemical properties and its role as a precursor in click chemistry reactions. Researchers particularly value its ability to participate in copper-catalyzed azide-alkyne cycloaddition (CuAAC), making it an essential component in bioconjugation and drug discovery workflows. The compound's molecular structure, featuring both an indazole core and a reactive terminal alkyne, offers multiple sites for chemical modification and structure-activity relationship studies.

Recent advances in cancer research have highlighted the importance of 3-Ethynyl-1H-indazole derivatives as potential kinase inhibitors. The indazole scaffold is known to interact with various biological targets, and the addition of the ethynyl group enhances its utility in creating targeted therapies. This aligns with current trends in precision medicine, where researchers seek compounds that can be precisely modified to interact with specific protein targets.

The synthetic versatility of 3-Ethynyl-1H-indazole makes it particularly valuable in combinatorial chemistry approaches. Pharmaceutical scientists frequently employ this compound in high-throughput screening libraries and fragment-based drug design strategies. Its moderate molecular weight (158.17 g/mol) and favorable lipophilicity parameters contribute to its popularity in lead optimization processes.

From a chemical property perspective, 3-Ethynyl-1H-indazole typically appears as a white to off-white crystalline powder with good solubility in common organic solvents like dimethyl sulfoxide (DMSO) and dichloromethane. The compound exhibits stability under standard laboratory conditions, though it requires protection from prolonged exposure to light and moisture to maintain its chemical integrity.

The global market for specialized pharmaceutical intermediates like 3-Ethynyl-1H-indazole has shown steady growth, driven by increasing investment in small molecule drug discovery. Contract research organizations and academic laboratories represent significant consumers of this compound, utilizing it in various stages of medicinal chemistry projects. The compound's relatively straightforward synthetic route contributes to its commercial availability from multiple chemical suppliers.

Quality control of 3-Ethynyl-1H-indazole typically involves analytical techniques such as high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy. These methods ensure the compound meets the purity standards required for pharmaceutical applications, typically ≥95% purity for most research purposes. Advanced purification methods may be employed for applications requiring ultra-high purity material.

In academic research, 3-Ethynyl-1H-indazole has found applications beyond traditional drug discovery. Materials scientists have explored its potential in creating functionalized polymers, while biochemists have utilized it in proteomics studies and chemical biology experiments. This broad applicability contributes to its growing presence in scientific literature and patent applications.

The future outlook for 3-Ethynyl-1H-indazole appears promising, particularly as researchers continue to develop novel catalytic systems for alkyne functionalization. The compound's compatibility with emerging green chemistry approaches and flow chemistry techniques positions it well for continued relevance in medicinal chemistry innovation. As the pharmaceutical industry places greater emphasis on molecular diversity and structural complexity, demand for versatile building blocks like 3-Ethynyl-1H-indazole is expected to rise accordingly.

For researchers working with 3-Ethynyl-1H-indazole, proper laboratory safety protocols should always be followed, including the use of appropriate personal protective equipment. While not classified as highly hazardous, standard precautions for handling organic compounds should be observed. The compound should be stored in tightly sealed containers under inert atmosphere when long-term stability is required.

From a regulatory perspective, 3-Ethynyl-1H-indazole currently falls under general chemical substance regulations in most jurisdictions. Researchers should consult local guidelines regarding its transportation and disposal. As with all research chemicals, proper documentation and inventory management practices are recommended to ensure compliance with institutional and governmental requirements.

The scientific community continues to explore new applications for 3-Ethynyl-1H-indazole, particularly in the development of covalent inhibitors and chemical probes. Its unique combination of structural features and reactivity makes it an attractive candidate for addressing current challenges in drug discovery, such as targeting undruggable proteins and developing selective inhibitors. As research progresses, we can anticipate seeing more innovative uses of this valuable chemical building block in both academic and industrial settings.

• 1383706-08-8(1H-Indazole, 5-bromo-3-ethynyl-)
• 1093307-29-9(5-Ethynyl-3-methyl-1H-indazole)
• 7746-28-3(3,6-Dimethyl-1H-indazole)
• 1383705-73-4(1H-Indazole, 3-ethynyl-5-methyl-)
• 1383706-61-3(1H-Indazole, 3-ethynyl-6-methyl-)
• 82453-35-8(Cinnoline, 3-(phenylethynyl)-)
• 3176-62-3(3-Methyl-1H-indazole)
• 1383706-60-2(3-ethynyl-6-fluoro-1H-Indazole)
• 395102-06-4(1H-Indazole-5-carbonitrile, 3-(phenylethynyl)-)
• 945265-03-2(5-Fluoro-3-methyl-1H-indazole)