Understanding Triazoles: Structural Features, Classification Logic, Typical Roles, Research Selection, and Product Navigation (Tables 1–4)

I. Introduction

Triazole is not a single c, but a class of five-membered aromatic heterocycles containing three nitrogen atoms and their derivatives. The importance of triazoles stems mainly from two directions. One is pharmaceuticals and agrochemicals, because many important antifungal drugs, some other drug lead structures, and numerous agricultural fungicides are closely related to the triazole scaffold. The other is synthesis and chemical biology, especially the central role of 1,2,3-triazole in azide–alkyne cycloaddition “click chemistry,” which has made it a classic structural unit for linking molecules, constructing probes, and rapidly building molecular libraries.

The triazole ring is small, planar, stable, nitrogen-rich, and capable of diverse interactions. Therefore, it can serve directly as a pharmacophore, or be incorporated into drugs, agrochemicals, materials, and bioconjugation systems as a linker, bioisostere, or coordination site.

II. What Is Triazole or the Triazole Class?

The triazole parent ring has the molecular formula C₂H₃N₃ and is a five-membered nitrogen-containing aromatic heterocycle composed of two carbon atoms and three nitrogen atoms. According to the arrangement of the three nitrogen atoms within the ring, the two most important types are 1,2,3-triazole and 1,2,4-triazole. Both are aromatic, but they are not identical in atomic arrangement, tautomerism, reactivity, or common application direction.

In terms of tautomerism, unsubstituted 1,2,3-triazole is commonly discussed in terms of 1H and 2H tautomers, whereas unsubstituted 1,2,4-triazole is commonly discussed in terms of 1H and 4H tautomers. For the parent ring itself, 1,2,3-triazole usually shows a slight preference for the 2H tautomer in aqueous solution, while 1,2,4-triazole is generally more stable as the 1H tautomer. In specific triazole derivatives, however, the tautomeric equilibrium can also vary with substituents, solvent, and environment, so it should not be generalized without context.

 

The term “triazole class” does not usually refer to a group of compounds that all share the molecular formula C₂H₃N₃. Rather, it refers to a broad class of compounds in which the triazole ring serves as the parent core, a key pharmacophore, a linking unit, or an important structural fragment. This class may include simple monocyclic triazoles, substituted triazoles, or more complex systems fused or annulated with other aromatic rings or heterocycles.

The table below helps clarify the “triazole class.” The classification logic summarized here is based mainly on the two constitutional isomeric forms of triazole, their tautomeric features, and their different functional roles in drug design, click chemistry, and materials chemistry.

Perspective	Key Content	Main Point
By the Arrangement of Nitrogen Atoms Within the Ring	1,2,3-Triazole; 1,2,4-Triazole	This is the most fundamental and most important classification.
By Structural Complexity	Monocyclic Triazoles; Substituted Triazoles; Fused/Annulated Triazoles	This influences subsequent reactivity, polarity, and application direction.
By Functional Role	Pharmacophore; Linking Unit; Bioisostere; Coordination Site	A triazole is not merely “a ring”; it can perform different functions.
By Application Scenario	Pharmaceuticals, Agrochemicals, Click Chemistry, Bioconjugation, Materials/Coordination Chemistry	The same “triazole” serves different tasks in different fields.

III. Structural Features of Triazoles

3.1 It Is a Small, Stable, Planar Aromatic Ring

Both 1,2,3-triazole and 1,2,4-triazole are planar five-membered aromatic heterocycles. A direct consequence of aromaticity is that this ring usually shows good chemical stability, while its planar and compact character allows it to be embedded easily into larger drug or functional-molecule frameworks without markedly increasing conformational complexity.

3.2 Its High Nitrogen Content Gives It Rich Noncovalent Interaction Capability

The triazole ring contains multiple nitrogen atoms, so it is usually more polar than a typical carbocycle and more able to participate in various noncovalent interactions. In general, triazoles often act as hydrogen-bond acceptors; in tautomers containing N–H, or when the ring is not fully substituted, they may also show some hydrogen-bond donor character. In addition, triazoles can participate in dipole-related interactions and, in suitable systems, aromatic stacking as well.

This is also one reason triazoles are so highly valued in drug design: their importance lies not only in being “nitrogen-rich,” but also in combining a certain degree of polarity, strong structural rigidity, and the potential to donate and accept hydrogen bonds. As a result, triazoles can help molecules establish more suitable recognition relationships with targets, and they are often used as bioisosteres or functional heterocyclic fragments to tune affinity, selectivity, solubility, and overall physicochemical properties.

3.3 1,2,3-Triazole Is Especially Suitable as a “Stable Linking Unit”

1,2,3-Triazole is extremely important in click chemistry. Copper-catalyzed azide–alkyne cycloaddition (CuAAC) can form 1,4-disubstituted 1,2,3-triazoles with high selectivity under mild conditions, which makes this ring one of the most commonly used bridges for linking two molecular segments. Importantly, this bridge is not “just for connection”; it may also participate in binding itself and is often more resistant than an ordinary amide bond to chemical and metabolic degradation.

3.4 1,2,4-Triazole Is More Common in Classical Triazole Antifungal Scaffolds

In clinical triazole antifungal drugs, 1,2,4-triazole is more common. One of its key values is that a nitrogen atom on the ring can serve as a crucial recognition site in binding to the target enzyme, so it is often used to build antifungal active scaffolds. In such drugs, the triazole ring does not merely provide an aromatic heterocyclic fragment; it often enters directly into the processes of enzyme recognition and inhibition. For this reason, 1,2,4-triazole has become one of the most common structural units in classical triazole antifungal drugs.

IV. Using Fluconazole as an Example to Understand the Role of Triazole in a Compound

Fluconazole is a clinically used triazole antifungal agent containing two 1,2,4-triazole rings. When it binds fungal CYP51, at least one nitrogen atom on a triazole ring can directly coordinate to the heme iron, thereby inhibiting the 14α-demethylation step catalyzed by lanosterol 14α-demethylase (CYP51). Once this process is blocked, ergosterol synthesis in fungal cells is suppressed and abnormal sterols accumulate, impairing the normal formation and functional maintenance of the cell membrane.

Observation Point	Role of Triazole in This Context	Key Takeaway
Target Recognition	Fluconazole contains two 1,2,4-triazole rings, and at least one triazole nitrogen can coordinate to the heme iron of fungal CYP51.	The triazole ring can directly participate in target recognition and inhibition, not merely occupy space.
Mechanistic Action	Inhibits the 14α-demethylation step catalyzed by lanosterol 14α-demethylase (CYP51), thereby blocking normal ergosterol biosynthesis.	The triazole scaffold can enter a clearly defined mechanistic chain.
Outcome	Ergosterol is depleted and abnormal sterols accumulate, damaging fungal cell membrane structure and function.	The antifungal action of triazoles is closely tied to sterol metabolic homeostasis.
Structural Design Significance	A nitrogen-rich aromatic heterocycle helps provide recognition sites while also contributing a certain degree of polarity and structural stability.	Triazoles often provide the dual value of “recognition” and “property tuning.”

V. Classification Logic for Triazoles

Classification Level	Classification Method	Main Categories	Significance of the Classification
Level 1: Core Structural Classification	By the Arrangement of the Three Nitrogen Atoms Within the Ring	1,2,3-Triazole; 1,2,4-Triazole	This is the most fundamental and central first-level classification of triazoles. The two isomers may differ in tautomerism, reactivity, coordination mode, and common application direction.
Level 2: Substitution and Scaffold Complexity	By the Position of Substitution on the Parent Ring and the Overall Complexity of the Scaffold	Unsubstituted Triazoles; N-Substituted Triazoles; C-Substituted Triazoles; Fused/Annulated Triazoles (Such as Benzotriazoles and Their Functionalized Derivatives)	This level explains why the “triazole class” expands from simple monocyclic parent rings to many derivatives. It also helps distinguish different application routes: monocyclic triazoles are more common in drug design, click chemistry, and molecular linking, whereas fused or annulated triazoles are more common in corrosion inhibition, UV absorption, sunscreen applications, and material functionalization.
Level 3: Research-Functional Classification	By the Actual Role Played by the Triazole in a Molecule	Directly Active Scaffold Type; Linker/Click-Construction Type; Bioisosteric Replacement and Conformational Constraint Type; Metal-Coordination/Material-Function Type	This level is closest to research-oriented selection because it answers the question, “Why choose a triazole?”

VI. Major Application Areas and Typical Roles of Triazoles

Application Area	Common Triazole Type	Core Role of Triazole in That Context
Antifungal Drugs and Medicinal Chemistry	1,2,4-Triazoles Are More Common	Acts as a pharmacophore involved in enzyme binding, helping improve affinity, selectivity, and metabolic stability.
Molecular Linking and Lead Optimization in Drug Discovery	1,2,3-Triazoles Are Very Common	Serves as a rigid linker, an amide bioisostere, or a heterocyclic replacement.
Click Chemistry and Bioconjugation	1,2,3-Triazole Is the Most Typical	Selectively connects two molecular segments under mild conditions for probes, labeling, conjugation, and library construction.
Agrochemistry	Mostly Triazole Fungicides, and Also Some Plant Growth Regulation Scenarios	Inhibits fungal sterol biosynthesis; some triazoles also affect plant hormone-related metabolism.
Coordination Chemistry, Materials, and Surface Functionalization	Both 1,2,3- and 1,2,4-Triazoles Are Seen	Serves as a nitrogen-containing coordination site to form metal complexes, coordination polymers, or surface-functional structures.

VII. In Which Research or Development Scenarios Should Triazoles Be Prioritized?

Need Scenario	Why Triazole Is Used	More Common Choice
Need to Quickly and Reliably Link Two Molecular Segments	CuAAC Can Form 1,2,3-Triazoles with High Selectivity Under Mild Conditions and with Strong Modularity	1,2,3-Triazole
Need to Replace an Insufficiently Stable Linkage with a More Robust Structure	1,2,3-Triazoles Can Often Serve as Amide Bioisosteres or Stable Linkers	1,2,3-Triazole
Need to Design Antifungals or Explore CYP51-Related Inhibitors	1,2,4-Triazoles Are More Common in Classical Triazole Antifungal Drugs	1,2,4-Triazole
Need to Increase Molecular Polarity and Multipoint Interaction Capability	Triazoles Can Provide Hydrogen-Bond Accepting, Dipolar, and Aromatic Interactions	Either Type, Depending on the Target
Need to Construct Metal Coordination Sites, Coordination Polymers, or Surface Functional Layers	The Triazole Ring Can Serve as a Nitrogen-Containing Coordination Unit	Either Type; Choose Based on the Specific Coordination Design

VIII. Key Considerations When Selecting or Using Triazoles

8.1 Distinguish Among “Pharmaceutical Triazoles,” “Agricultural Triazoles,” and “Click-Generated Triazoles”

All three categories may contain a triazole ring, but their functional objectives are not the same. Agricultural triazoles are often related to fungicidal activity and plant growth regulation, clinical triazoles are more concerned with antifungal activity and pharmacokinetic safety, and click-generated 1,2,3-triazoles often serve in linking and conjugation tasks.

8.2 When Using Click Chemistry in Biological Systems, Assess the Impact of Copper in the Specific Context

CuAAC is a classical method for constructing 1,2,3-triazoles and is extremely important in small-molecule linking, bioconjugation, and probe construction. However, in live-cell or in vivo systems, copper-ion toxicity, oxidative side reactions, and residual copper still require careful evaluation. Therefore, in many live-cell labeling or in vivo application scenarios, researchers often prioritize copper-free click systems. This does not mean CuAAC cannot be used in biological systems; with optimized ligands, copper sources, and reaction conditions, it can also be used in some live-cell experiments.

8.3 With Triazole Antifungal Agents, Pay Attention to Resistance and Drug–Drug Interactions

Triazole antifungal agents are extremely important in mechanistic studies and pharmacological experiments, but their use should not focus only on antifungal activity itself. In addition to resistance issues, these drugs often involve CYP-mediated drug interactions, so extra caution is needed in clinically related studies, efficacy evaluation, or combination-therapy design.

For example, fluconazole can inhibit CYP2C9, CYP2C19, and CYP3A4, with stronger inhibition of CYP2C19. When it is used together with other drugs metabolized by these enzymes, it may increase drug exposure or the risk of adverse reactions. In research work, it is best to consider “pharmacodynamic effects” and “metabolic interactions” separately when designing pharmacological experiments, interpreting results, or selecting positive controls.

8.4 Substitution Position, Substituents, and the Overall Scaffold Are Often More Important Than Simply “Whether a Triazole Is Present”

The triazole ring is indeed valuable, but final properties are still determined by the whole molecule. Different substitution patterns can markedly affect solubility, lipophilicity, acid–base behavior, target binding, and metabolic performance, so one should not infer identical functions simply because a compound “contains a triazole.”

IX. Triazole Product Navigation: Quickly Locate Tables 1–4 by Research Task

Research Task / Experimental Need	Product Types to Focus On	Recommended Table	How This Table Helps
For Pesticide Residue Analysis, Standard Preparation, and GC/LC-MS Method Development	Agricultural Triazole Fungicide Standards and Standard Solutions	Table 1	Table 1 concentrates agricultural triazole products and is especially suitable for residue analysis, method validation, and quality control in food, agricultural products, and environmental samples.
For Activity Screening in Crop Disease Control and for DMI/CYP51-Related Research	Active Agricultural Triazole Fungicides	Table 1	If the focus is the activity, mechanism of action, resistance comparison, or formulation evaluation of triazole fungicides, Table 1 is the most direct starting point.
For Plant Growth Regulation, Plant Height Control, Internode Elongation Inhibition, and Gibberellin-Pathway Experiments	Triazole Plant Growth Regulators Such as Paclobutrazol and Uniconazole	Table 1	Table 1 also includes triazole plant growth regulators and is suitable for plant physiology, horticultural control, and growth-inhibition studies.
For Antifungal Susceptibility Testing, Fungal Infection Models, and Antifungal Mechanism Studies	Fluconazole, Itraconazole, Voriconazole, Posaconazole, Isavuconazole, etc.	Table 2	Table 2 is the most concentrated table of pharmaceutically active triazoles and is suitable for susceptibility evaluation, mechanism studies, positive controls, and pharmacological experiments.
For Studies on Antifungal Prodrugs, Formulation Conversion, or Active Drug–Prodrug Relationships	Isavuconazonium Sulfate, Isavuconazole	Table 2	When the emphasis is prodrug design, conversion efficiency, solubility improvement, or formulation development rather than general susceptibility testing, Table 2 is more suitable.
For Breast Cancer Endocrine Therapy, Estrogen-Synthesis Inhibition, and Aromatase-Related Experiments	Anastrozole, Letrozole	Table 2	Table 2 contains not only antifungal agents, but also triazole aromatase inhibitors, making it suitable for endocrine oncology and hormone-regulation research.
For Antiviral Research, Nucleoside-Analog Pharmacology, or Viral Replication Inhibition Studies	Ribavirin	Table 2	If the research object is triazole nucleoside analogs and their antiviral uses, start with Table 2.
For Triazole Core Synthesis, Heterocyclic Methodology, and Screening of Substituted Triazole Precursors	1,2,4-Triazole, 1H-1,2,3-Triazole, 2H-1,2,3-Triazole, 3-Amino-1,2,4-Triazole	Table 3	Table 3 is best for basic synthesis and scaffold-level work, making it easy to start from the most fundamental triazole units for derivatization or methodological studies.
For Comparative Studies of Basic Triazole Structure, Tautomerism, and Ring-System Properties	1H-1,2,3-Triazole, 2H-1,2,3-Triazole, 1,2,4-Triazole	Table 3	When the target is not ready-made application molecules but the structure, isomerism/tautomerism, and basic properties of triazoles themselves, Table 3 should be consulted first.
For Catalase Inhibition, Oxidative Stress, or Biochemical Tool Experiments	3-Amino-1,2,4-Triazole	Table 3	In Table 3, 3-amino-1,2,4-triazole can be viewed not only as a basic triazole intermediate, but also as a functional tool molecule in biochemical research.
For Polymer Weatherability, Anti-UV Aging, and Photostability Studies of Coatings/Plastics	Benzotriazole UV Absorber	Table 4	Table 4 focuses on functionalized benzotriazole derivatives and is especially suitable for stabilization studies of polymers, engineering plastics, coatings, and outdoor materials.
For Sunscreen Formulations, Photostability Evaluation, and UVA/UVB Filter-Related Experiments	Sunscreen Actives Such as Drometrizole Trisiloxane	Table 4	If the research concerns cosmetic or sunscreen systems, Table 4 helps locate relevant UV-filter actives more directly.
For Copper and Copper-Alloy Corrosion Inhibition, Water-Treatment Anticorrosion, and Metal Surface Protection Studies	Benzotriazole, Methylbenzotriazole (TTA)	Table 4	The benzotriazole corrosion inhibitors in Table 4 are closer to industrial anticorrosion and material-protection needs and are suitable for water treatment, metal protection, and formulation development.

Table 1｜Agricultural Triazoles: Triazole Fungicides and Plant Growth Regulators

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Agricultural Triazole Fungicide	55219-65-3	T109895	Triadimenol	Analytical standard, mixture of isomers	Typical agricultural triazole fungicide standard; used for pesticide residue analysis, method development, quality control, and research related to triazole fungicides.
Agricultural Triazole Fungicide	60207-90-1	T114972	Propiconazole	Analytical standard, mixture of isomers	Typical agricultural triazole fungicide standard; commonly used for quantitative propiconazole residue analysis, method validation, and quality control in agricultural products and environmental samples.
Agricultural Triazole Fungicide	43121-43-3	T109948	Triadimefon solution	Analytical standard, 10ug/ml in petroleum ether	Triazole pesticide standard solution; convenient for direct standard preparation in GC/GC-MS and related methods, and used for triadimefon residue analysis and instrument calibration.
Agricultural Triazole Fungicide	131983-72-7	T114742	Triticonazole	Analytical standard, ≥99.2%	Agricultural triazole fungicide standard; suitable for residue analysis related to cereal and other crop diseases, quality control, and standard-curve establishment.
Agricultural Triazole Fungicide	107534-96-3	T110039	Tebuconazole	Analytical standard, ≥99%	Broad-spectrum triazole fungicide standard; commonly used for tebuconazole residue monitoring, method development, and reference quantification in food and environmental samples.
Agricultural Triazole Fungicide	88671-89-0	M117283	Myclobutanil	Analytical standard, ≥98.5%	Standard for a triazole sterol-biosynthesis inhibitor; suitable for myclobutanil residue testing, formulation analysis, and quality-control studies.
Agricultural Triazole Fungicide	79983-71-4	H109963	Hexaconazole	Analytical standard, ≥98%	Broad-spectrum triazole fungicide standard; commonly used for hexaconazole residue analysis, method validation, and pesticide reference-material comparison.
Agricultural Triazole Fungicide	119446-68-3	D109735	Difenoconazole	Analytical standard, ≥98%	Typical triazole fungicide standard; suitable for difenoconazole residue testing, quality control, and multi-residue method development.
Agricultural Triazole Fungicide	114369-43-6	F117281	Fenbuconazol	Analytical standard	Agricultural triazole fungicide standard; suitable for fenbuconazol residue testing, method development, and quantitative sample analysis.
Agricultural Triazole Fungicide	66246-88-6	P769212	Penconazole	Moligand™,≥98%	Systemic triazole fungicide; often used as an active agrochemical molecule, in formulation studies, or as an analytical reference for research related to sterol demethylation inhibition.
Next-Generation Agricultural Triazole Fungicide	1417782-03-6	M651053	Mefentrifluconazole	≥99%	Next-generation triazole fungicide; often used for new pesticide activity evaluation, resistance studies, and agrochemical analytical reference.
Agricultural Triazole Fungicide	76674-21-0	F1421303	Flutriafol	≥98%	Systemic triazole fungicide; often used for pesticide activity studies, residue quantification, and analytical reference.
Agricultural Triazolethione Fungicide	178928-70-6	P331163	Prothioconazole	≥97%	Systemic triazolethione fungicide; often used in pesticide activity, resistance, and metabolic transformation studies.
Agricultural Triazole Fungicide	112281-77-3	T1421306	Tetraconazole	——	Systemic triazole fungicide; often used for tetraconazole residue analysis, quality control, and agrochemical research.
Agricultural Triazole Plant Growth Regulator	76738-62-0	P109934	Paclobutrazol solution	Analytical standard, 10ug/ml in methanol	Triazole plant growth regulator standard solution; commonly used for paclobutrazol residue testing, plant hormone regulation studies, and method standard preparation.
Agricultural Triazole Plant Growth Regulator	83657-22-1	U114871	Uniconazole	Analytical standard, ≥97.5%	High-activity triazole plant growth regulator standard; commonly used for plant height control, gibberellin-pathway studies, and residue analysis.

Table 2｜Pharmaceutically Active Triazoles: Antifungals, Aromatase Inhibitors, and Antivirals

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Pharmaceutical Triazole Antifungal	171228-49-2	P125008	Posaconazole	Moligand™, ≥99%	Broad-spectrum triazole antifungal; commonly used in invasive fungal studies, susceptibility evaluation, mechanism studies, and as a drug reference.
Pharmaceutical Triazole Antifungal	84625-61-6	I129771	Itraconazole	Moligand™, ≥98%(HPLC)	Classical triazole antifungal; commonly used in fungal susceptibility testing, CYP-related interaction studies, and drug analysis.
Pharmaceutical Triazole Antifungal	137234-62-9	V129745	Voriconazole	Moligand™, ≥98%	Broad-spectrum triazole antifungal; commonly used in invasive aspergillosis studies, susceptibility tests, and clinical pharmacology-related experiments.
Pharmaceutical Triazole Antifungal	86386-73-4	E129360	Fluconazole	Moligand™, ≥98%	Classical water-soluble triazole antifungal; commonly used in Candida/Cryptococcus-related experiments, susceptibility testing, and method development.
Triazole Antifungal Prodrug/Formulation Research Tool	946075-13-4	I646374	Isavuconazonium sulfate	Moligand™, ≥96%	Prodrug of isavuconazole; suitable for prodrug-to-active-drug conversion, formulation solubility optimization, and antifungal research.
Pharmaceutical Triazole Antifungal	241479-67-4	I337027	Isavuconazole	≥98%	Broad-spectrum triazole antifungal; commonly used in invasive fungal infection models, susceptibility testing, and mechanism studies.
Pharmaceutical Triazole Antifungal	182760-06-1	R587786	Ravuconazole	≥98%	Research-stage broad-spectrum triazole antifungal; commonly used for comparison of novel antifungal candidates, susceptibility evaluation, and mechanism assessment.
Pharmaceutical Triazole Antifungal	67915-31-5	T344675	Terconazole	≥98%	Triazole antifungal; mainly used in vaginal candidiasis-related experiments, susceptibility evaluation, and topical formulation studies.
Triazole Aromatase Inhibitor	120511-73-1	A126470	Anastrozole	Moligand™, ≥99%	Nonsteroidal aromatase inhibitor; commonly used in estrogen-synthesis inhibition, breast cancer-related mechanism studies, and as a pharmacological control.
Triazole Aromatase Inhibitor	112809-51-5	L129473	Letrozole (CGS 20267)	Moligand™, ≥98%	Nonsteroidal aromatase inhibitor; commonly used in endocrine therapy studies, estrogen-reduction experiments, and as a pharmacological reference.
Triazole Nucleoside Analog Antiviral	36791-04-5	R101754	Ribavirin	Moligand™, ≥98%	Triazole nucleoside analog antiviral; commonly used in viral replication inhibition, nucleoside metabolism, and pharmacodynamic control studies.

Table 3｜Basic Triazole Scaffolds and General Intermediates

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
1,2,4-Triazole Basic Scaffold / Intermediate	61-82-5	A107201	3-Amino-1,2,4-triazole	Analytical standard	Combines the attributes of a classical herbicide and a biochemical tool; commonly used in catalase inhibition experiments and can also serve as a reference triazole intermediate.
1,2,4-Triazole Basic Scaffold / Intermediate	288-88-0	T100645	1,2,4-Triazole	≥99%	Basic 1,2,4-triazole scaffold; commonly used as a building block for heterocycle synthesis and also as a reference in metabolic and transformation studies of various triazole pesticides/drugs.
1,2,3-Triazole Basic Scaffold / Intermediate	288-36-8	H157233	1H-1,2,3-Triazole	≥98%	One of the basic 1,2,3-triazole tautomers; commonly used as a structural reference in click chemistry-related studies, heterocycle synthesis, and method development.
1,2,3-Triazole Basic Scaffold / Intermediate	288-35-7	H588581	2H-1,2,3-Triazole	≥98%	One of the basic 1,2,3-triazole tautomers; commonly used in triazole ring chemistry, tautomerism, and synthetic method studies.

Table 4｜Benzotriazoles and Functional Derivatives: UV Absorption, Sunscreen Applications, and Corrosion Inhibition

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Benzotriazole Sunscreen Active	155633-54-8	D710363	Drometrizole Trisiloxane	analytical standard, ≥98%	Benzotriazole sunscreen active ingredient; provides both UVA and UVB filtering and is commonly used in sunscreen formulations, photostability studies, and skin-delivery research.
Benzotriazole UV Absorber	2440-22-4	H157228	2-(2-Hydroxy-5-methylphenyl)benzotriazole	≥99%	Benzotriazole UV absorber; commonly used in weathering-stability studies of plastics, coatings, and polymer materials.
Benzotriazole Corrosion Inhibitor / Intermediate	95-14-7	B101002	1H-Benzotriazole	≥99%	Classical benzotriazole; commonly used for corrosion inhibition of copper and copper alloys, water-treatment formulations, anti-fogging in photography, and intermediate studies.
Benzotriazole UV Absorber	3147-75-9	H135447	2-(2H-benzotriazol-2-yl)-4-(1，1，3，3-tetramethylbutyl)phenol	≥98%(HPLC)	Typical benzotriazole UV absorber; suitable for light-aging studies of polymers, coatings, and outdoor materials.
Benzotriazole UV Absorber	3896-11-5	C153529	2-(5-Chloro-2-benzotriazolyl)-6-tert-butyl-p-cresol	≥98%(HPLC)	Benzotriazole UV absorber; commonly used in UV-aging resistance and formulation screening for plastics, rubber, and coating systems.
Methylbenzotriazole Corrosion Inhibitor	29385-43-1	M158120	Methyl-1H-benzotriazole (mixture)(TTA)	≥98%(GC)	Mixture of methylbenzotriazoles; commonly used in copper corrosion inhibition, anticorrosion formulation development, and industrial recirculating-water system studies.
Benzotriazole High-Efficiency UV Absorber / Polymer Weatherability Additive	103597-45-1	M158087	2,2'-Methylenebis[6-(benzotriazol-2-yl)-4-tert-octylphenol]	≥98%	High-efficiency benzotriazole UV absorber for polymer materials; suitable for studies on thick products, engineering plastics, and long-term weathering systems.
Benzotriazole UV Absorber	25973-55-1	D155329	2-(3,5-Di-tert-amyl-2-hydroxyphenyl)benzotriazole	≥98%	Benzotriazole UV absorber; commonly used in photostabilization studies of polyolefins, engineering plastics, and coating systems.

Note: The products above are representative Aladdin products. For more specifications, please refer to the product list at the end of the article or search the Aladdin website by “product name / CAS / catalog number.”

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