Synthetic Application Logic of Triazoles and Related Compounds: Structural Introduction, Reactive Sites, and Target Molecule Construction

1 Introduction

Triazole intermediates are a class of synthetic building blocks that either contain a triazole structure or can be used to construct a triazole structure. Their value in synthetic routes is mainly reflected in three aspects: introducing a triazole core, linking different molecular fragments, and providing reactive sites for further transformation.

The triazole ring consists of three nitrogen atoms and two carbon atoms. It features aromatic stability, polarity associated with multiple nitrogen atoms, hydrogen-bonding capability, and potential for metal coordination. These structural characteristics explain why triazoles are widely used in pharmaceuticals, agrochemicals, ligands, materials, high-nitrogen molecules, and other research fields. However, for triazole intermediates, the more important question is how they participate in the construction of target molecules.

Understanding triazole intermediates can be approached by considering the following questions:

① Does the intermediate provide a 1,2,3-triazole, a 1,2,4-triazole, or a benzotriazole-related structure?

② Is its reactive site located at an N position, a C position, or on an external functional group?

③ Is it more suitable to form the triazole ring first and then modify it, or to construct the ring at a later stage using azide and alkyne fragments?

④ Does it function in the route as a core-introducing unit, a fragment-linking unit, a functional-group transformation handle, or a carboxylic acid activation component?

2 Basic Concepts of Triazole Intermediates

2.1 Types of Triazole Cores

Triazoles are five-membered aromatic heterocycles containing three nitrogen atoms and two carbon atoms. Based on the arrangement of the three nitrogen atoms in the five-membered ring, the common core structures mainly include 1,2,3-triazoles and 1,2,4-triazoles.

Type	Schematic Arrangement of Ring Atoms	Structural Characteristics	Common Role in Synthesis
1,2,3-Triazole	N1—N2—N3—C4—C5—back to N1	Three nitrogen atoms are arranged consecutively	Commonly generated by azide–alkyne cycloaddition and often used as a stable linker structure
1,2,4-Triazole	N1—N2—C3—N4—C5—back to N1	The nitrogen atoms are more dispersed in the ring	Commonly used as a nitrogen-containing heterocyclic core for substitution modification, coordination structures, and construction of functional molecules

2.2 Criteria for Identifying Triazole Intermediates

Triazole intermediates are functional structural units in synthetic routes. They may be compounds that already contain a triazole ring, or they may be azide or alkyne precursors used to construct a triazole ring. Their synthetic value can be evaluated from three perspectives.

Evaluation Aspect	Core Question	Typical Structure or Function
Structural source	Does it provide a triazole or triazole-related structure?	1,2,3-Triazole, 1,2,4-triazole, benzotriazole structure
Reactive site	Does it contain a functional group that can undergo further transformation?	N-H, amino, mercapto, nitro, halogen, hydroxymethyl, azido, alkynyl groups, etc.
Synthetic role	Can it participate in target molecule construction?	Core modification, fragment linking, amide coupling, ligand construction, preparation of material monomers

3 Three Synthetic Roles of Triazole Intermediates

Based on their synthetic roles, triazole intermediates can be divided into three categories: core-type intermediates, linker-construction intermediates, and synthesis-assisting intermediates.

3.1 Core-Type Intermediates: Forming the Triazole Ring First, Followed by Structural Modification

Core-type intermediates already contain a triazole ring and retain sites that can be further modified. Representative structures include 1,2,4-triazole, 1H-1,2,3-triazole, aminotriazoles, mercaptotriazoles, nitrotriazoles, and certain alkyl-, halo-, and hydroxymethyl-substituted triazoles.

Synthetic route logic of core-type triazole intermediates:

Triazole core → N-substitution, C-position modification, acylation, condensation, thioetherification, coordination → triazole derivatives → target molecular fragments or functional structural units

This type of intermediate is suitable for systematic structural design centered on the triazole ring. Its advantage lies in the clearly defined core, which can be further modified at the N position, C position, or through external functional groups. It should be noted that triazoles may exhibit tautomerism, and N-substitution as well as C-position transformation may be affected by regioselectivity. For structures sensitive to substitution position, the actual structure should be confirmed using data such as NMR, mass spectrometry, elemental analysis, or single-crystal structure analysis.

3.2 Linker-Construction Intermediates: Preparing Azide and Alkyne Fragments First, Then Forming the Triazole Ring

Linker-construction intermediates usually refer to precursors such as organic azides and terminal alkynes. They do not necessarily contain a triazole ring themselves, but they can generate a 1,2,3-triazole linker structure through a cycloaddition reaction.

A typical reaction is the copper-catalyzed azide–alkyne cycloaddition reaction, commonly known as Copper-Catalyzed Azide-Alkyne Cycloaddition, or CuAAC. CuAAC usually uses organic azides and terminal alkynes as substrates and regioselectively generates 1,4-disubstituted 1,2,3-triazoles under Cu(I) catalysis.

R—N₃ + HC≡C—R′ —[Cu(I) catalysis]→ 1-R-4-R′-1,2,3-triazole

Here, R usually originates from the organic azide fragment and corresponds to the N1 substituent of the 1,2,3-triazole product; R′ usually originates from the terminal alkyne fragment and corresponds to the C4 substituent of the product, while the C5 position typically retains a hydrogen atom.

The value of this type of route lies in linking two molecular fragments through a triazole ring. Compared with thermally promoted Huisgen 1,3-dipolar cycloaddition, CuAAC is characterized by high reaction efficiency and generally favors the formation of the 1,4-disubstituted product. In contrast, thermally promoted reactions may yield a mixture of 1,4- and 1,5-disubstituted isomers.

Synthetic Role	Specific Significance
Fragment linking	Links two molecular fragments through a 1,2,3-triazole ring
Regioselectivity	CuAAC generally favors formation of the 1,4-disubstituted product
Structural stability	The resulting 1,2,3-triazole ring has good chemical stability
Spatial orientation control	The triazole ring helps maintain a relatively defined spatial relationship between the two substituents

3.3 Synthesis-Assisting Intermediates: Benzotriazole-Related Structures for Carboxylic Acid Activation

Benzotriazole-related reagents are widely used in the construction of amide bonds and peptide bonds. Their role is to promote the reaction between carboxylic acids and amines through carboxylic acid activation. Representative reagents include:

Abbreviation	Full Name	Main Function
HOBt	1-Hydroxybenzotriazole	Forms OBt activated structures and promotes amide coupling
HOAt	1-Hydroxy-7-azabenzotriazole	Forms OAt activated structures and improves the efficiency of certain coupling reactions
HBTU	O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate	Uronium-type coupling reagent associated with the OBt activation system
HATU	O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate	Uronium-type coupling reagent associated with the OAt activation system

OBt refers to the benzotriazolyloxy group, and OAt refers to the 7-azabenzotriazolyloxy group. Coupling reagents such as HBTU and HATU, as well as additives or leaving-group precursors such as HOBt and HOAt, can participate in carboxylic acid activation, increase the reactivity of the carboxylic carbonyl toward amines, and reduce the risk of racemization in certain systems.

Simplified route of a benzotriazole-type activation system:

R—COOH

↓ Activation by a coupling reagent or additive

R—CO—OBt or R—CO—Oat

↓ H₂N—R′

R—CONH—R′

In this route, benzotriazole-related structures mainly serve the functions of carboxylic acid activation and leaving-group regulation. The final target products are usually amides or peptide structures.

4 Reactive Sites and Downstream Transformation Directions

The downstream transformation direction of a triazole intermediate is determined by its reactive site. Different sites correspond to different reaction types and also determine which type of synthetic route the intermediate is more suitable for.

Reactive Site	Typical Structure	Main Transformation Direction	Key Considerations When Selecting
N-H	Unsubstituted triazoles	N-alkylation, N-acylation, salt formation, coordination	Tautomerism and regioselectivity of N-substitution
Transformable C-position groups	Halo-, amino-, nitro-, and ester-substituted triazoles, etc.	Substitution, reduction, condensation, coupling, or further functional-group transformation	Ordinary C-H bonds should not be directly regarded as general-purpose reactive sites
—NH₂	Aminotriazoles, diaminotriazoles	Acylation, condensation, urea formation, hydrogen-bond construction, ligand extension	Amino/imino tautomerism and reaction selectivity
—SH / =S	Mercaptotriazoles, thione-type triazoles	Thioetherification, metal coordination, surface adsorption	Thiol/thione tautomerism and multi-site N/S interactions
—NO₂	Nitrotriazoles	Electronic-effect regulation, reductive transformation, high-nitrogen structure design	Thermal behavior, safety profile, and storage conditions
—N₃ / —C≡CH	Organic azides, terminal alkynes	Cycloaddition to generate 1,2,3-triazoles	Azide stability, alkyne position, and click reaction conditions
OBt / OAt activated structures	HOBt-, HOAt-, HBTU-, and HATU-related intermediates	Carboxylic acid activation and amide bond formation	Racemization risk, substrate steric hindrance, coupling efficiency, and safety

4.1 N-H Site

Unsubstituted triazoles contain an N-H site that can participate in tautomerism and substitution reactions. This site can be used for N-alkylation, N-acylation, salt formation, or coordination regulation.

N-substitution changes the hydrogen-bond donor ability, basicity, polarity, solubility, and metal coordination mode of the triazole structure. If subsequent N-substitution is required, the N-H structure should be retained. If the target molecule requires fixed polarity and hydrophobicity, an N-alkyl group or another N-substituent may be introduced in advance.

Triazole N-substitution may involve regioselectivity issues. For 1,2,3-triazole and 1,2,4-triazole derivatives, the actual substitution position should be confirmed through structural characterization.

4.2 Transformable C-Position Groups

The reactive value of the triazole C position usually comes from preintroduced transformable functional groups, such as halogens, amino groups, nitro groups, ester groups, aldehyde groups, or hydroxymethyl groups. Different functional groups can correspond to downstream reactions such as substitution, reduction, condensation, coupling, esterification, or amidation.

C-position transformation has a clear influence on the spatial orientation of the target molecule. For example, in 1,4-disubstituted and 1,5-disubstituted 1,2,3-triazoles, the relative orientation of the two substituents differs, which may affect molecular conformation, binding mode, aggregation behavior, or material structure.

4.3 Amino Site

Aminotriazole intermediates contain both a triazole ring and an external amino group. The amino group can participate in acylation, condensation, urea formation, and multi-point hydrogen bonding, making these intermediates suitable for structural extension, ligand construction, and functional molecule design. Common transformations include:

Transformation Type	Structure Formed	Synthetic Significance
Acylation	Triazole amides	Introduces a carbonyl-linked structure
Condensation	Imines, heterocycle-expanded structures	Extends conjugation or constructs new heterocycles
Urea formation	Urea derivatives	Increases the number of hydrogen-bonding sites
Coordination	Polynitrogen ligand structures	Enhances metal-binding capability

Some aminotriazoles may exhibit amino/imino tautomerism. Their reactive sites and product structures should be determined based on reaction conditions and characterization data.

4.4 Mercapto Site

Mercaptotriazole intermediates often involve thiol–thione tautomerism. Because these molecules contain both triazole nitrogen atoms and sulfur atoms, they have rich interaction sites with metal ions or metal surfaces. Common transformations include:

Transformation Type	Structure Formed	Synthetic Significance
Thioetherification	Triazole—S—R	Introduces a sulfur-containing linker structure
Metal coordination	Multi-site N/S coordination structures	Constructs ligands or metal complexes
Surface adsorption	Adsorbed layers on metal surfaces	Used in studies of metal surface interactions

The reaction behavior of mercaptotriazoles is influenced by tautomerism, solvent, pH, metal ion species, and substituents. When using them, it is important to distinguish between thiol-type reactions, thione-type structures, and metal coordination behavior.

4.5 Nitro Site

Nitrotriazole intermediates combine a high-nitrogen heterocycle with a strongly electron-withdrawing substituent. The nitro group changes the electron distribution, acid–base properties, thermal behavior, and downstream transformation activity of the triazole ring. Common roles include:

Role	Specific Influence
Electron-withdrawing effect	Reduces ring electron density and affects acid–base properties and reactivity
Reductive transformation	Can serve as a precursor to structures such as aminotriazoles
High-nitrogen structure design	Used in research on high-nitrogen heterocycles and energetic structures
Thermal behavior regulation	Changes decomposition temperature, thermal stability, and safety profile

Nitrotriazoles and other high-nitrogen intermediates should be evaluated in combination with safety data sheets, thermal analysis data, and experimental conditions. Risk control is especially important during scale-up, heating, grinding, or long-term storage.

4.6 Azide/Alkyne Groups and OBt/OAt Activated Structures

Azido and alkynyl groups correspond to a post-cyclization construction route for 1,2,3-triazoles. Their core function is to generate triazole linker structures through cycloaddition reactions, making them suitable for fragment conjugation and late-stage structural linking.

OBt and OAt activated structures correspond to carboxylic acid activation and amide bond formation. Their core function is to increase the reactivity of the carboxylic carbonyl, making it easier for amines to attack and generate amide bonds. Such structures usually exist as activated structures during the coupling process and are not necessarily retained in the final product.

5 Selection Criteria for Triazole Intermediates

When selecting triazole intermediates, the target task should first be identified, followed by determination of the appropriate intermediate type.

5.1 Introducing a Triazole Core

When the target molecule needs to retain a triazole ring, core-type intermediates should be prioritized. The key to a core-type route is determining how the triazole ring is retained in the target molecule and where it is substituted.

Objective	Preferred Intermediate	Key Evaluation Points
Introducing a 1,2,4-triazole structure	1,2,4-Triazole and its substituted derivatives	N-substitution position, C-position functional groups, downstream modification conditions
Introducing a 1,2,3-triazole structure	1H-1,2,3-triazole or an azide/alkyne post-cyclization route	Direct core modification or construction through CuAAC
Constructing polynitrogen ligands	Amino-, mercapto-, and diaminotriazoles	Coordination sites, hydrogen-bonding sites, and substitution direction
Constructing high-nitrogen structures	Amino-, nitro-, and diaminotriazoles	Thermal behavior, safety profile, and downstream transformation capability

5.2 Linking Two Molecular Fragments

When the objective is to link two molecular fragments, azide/alkyne precursors and the CuAAC route should be prioritized. The key to this route lies in precursor design. Which fragment bears the azido group and which bears the alkynyl group will affect reaction efficiency, regioselectivity, purification strategy, and the final spatial relationship within the molecule.

Question to Consider	Corresponding Consideration
Which fragment is suitable for introducing an azido group?	Stability, preparation method, and safety of the azide compound
Which fragment is suitable for introducing a terminal alkyne?	Alkyne introduction conditions and effects on other functional groups
Is a 1,4-disubstituted structure required?	CuAAC is generally suitable for constructing 1,4-disubstituted 1,2,3-triazoles
Is sensitivity to metal residues a concern?	Copper residue and purification should be considered in biological or material systems
Is late-stage linking required?	Click reactions are suitable for fragment conjugation and late-stage structural linking

5.3 Providing Coordination, Hydrogen-Bonding, or Electronic-Regulation Sites

When the target structure requires enhanced coordination ability, hydrogen-bonding interactions, or electronic regulation, the intermediate should be selected based on its functional groups. This type of selection requires simultaneous consideration of the desired function and the reaction conditions. Amino groups affect acid–base properties and hydrogen bonding; mercapto groups may undergo tautomerism or oxidation; nitro groups and high-nitrogen structures require attention to thermal behavior and safety profile.

Target Function	Preferred Intermediate	Main Reason
Increasing hydrogen-bonding ability and structural extension capability	Aminotriazoles, diaminotriazoles	Amino groups can participate in acylation, condensation, and hydrogen-bond construction
Enhancing metal coordination or surface interaction	Mercaptotriazoles, N/S multi-site triazoles	Nitrogen and sulfur sites can jointly participate in coordination or adsorption
Regulating ring electron distribution	Nitrotriazoles, halotriazoles	Electron-withdrawing groups change ring electron density and downstream reactivity
Constructing high-nitrogen structures	Amino-, nitro-, and diaminotriazoles	Provide high-nitrogen aromatic frameworks and sites for further modification

5.4 Constructing Amide Bonds or Peptide Bonds

When the objective is to promote amide bond formation between a carboxylic acid and an amine, a benzotriazole-type activation system should be considered.

Objective	Reagent Types to Consider	Key Evaluation Points
Conventional amide coupling	DCC/HOBt, EDCI/HOBt, HBTU, etc.	Activation efficiency and substrate compatibility
Sterically hindered or difficult-to-couple substrates	HATU, DCC/HOAt, EDCI/HOAt, etc.	Reaction efficiency and side-reaction control
Substrates containing chiral centers	HOBt- and HOAt-related systems	Racemization risk and mildness of reaction conditions
Peptide synthesis	HATU, HBTU, HOAt, HOBt, etc.	Coupling efficiency, purification, and safe handling

The synthetic roles of HOBt, HOAt, HATU, and HBTU lie in carboxylic acid activation and amide bond construction. Evaluation criteria include substrate steric hindrance, reaction efficiency, racemization risk, purification difficulty, and safe handling requirements. In particular, benzotriazole-type hydroxy reagents such as HOBt and HOAt should not be subjected to uncontrolled drying, grinding, heating, or scale-up operations.

5.5 Evaluation for Scale-Up and Process Use

Whether an intermediate can be used for scale-up or in a process route depends on its stability, safety, selectivity, purification difficulty, and downstream compatibility.

Factor	Evaluation Content
Stability	Whether it is prone to moisture absorption, decomposition, oxidation, or tautomerism-related effects
Safety	Whether it contains azido, nitro, high-nitrogen, or potentially sensitive structures
Selectivity	Whether N-substitution or C-substitution can readily afford a single product
Purification difficulty	Whether it tends to form isomers, salt forms, or coordination byproducts
Downstream compatibility	Whether it affects subsequent click reactions, condensation, coupling, or coordination reactions

Azide compounds, nitrotriazoles, high-nitrogen intermediates, and certain benzotriazole-type hydroxy reagents should be used in accordance with safety data sheets and laboratory safety protocols. Intermediate selection requires a balance among reaction activity, stability, selectivity, and operational practicality.

6. Classification Table of Representative Chemicals of Triazoles and Related Structures

Table 1 Reference Compounds with Structurally Similar Nitrogen-Containing Heterocycles

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Reference compound of a related diazole five-membered heterocycle	288-32-4	I432539	Imidazole	Anhydrous, ACS, ≥99%	Used to compare the differences between diazole five-membered rings and triazoles in terms of nitrogen atom number, basicity, hydrogen-bonding interactions, and metal coordination ability
Reference compound of a related diazole five-membered heterocycle	288-13-1	P100994	Pyrazole	≥98% (GC)	Used to compare nitrogen atom arrangement, tautomerism, substitution direction, and structural differences from triazoles
Reference compound of a related high-nitrogen five-membered heterocycle	4418-61-5	A151135	5-Amino-1H-tetrazole	≥98%	Used for comparison with aminotriazoles in terms of high-nitrogen framework, hydrogen-bonding interactions, acid–base properties, and structural extension capability
Reference compound of a related high-nitrogen five-membered heterocycle	288-94-8	T109596	Tetrazole	≥98%	Used to compare tetrazole-type high-nitrogen heterocycles with triazoles in terms of nitrogen content, acidity, coordination, and structural mimicry

Table 2 Triazole Core and Functionalized Triazole Intermediates

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Basic triazole core intermediate	61-82-5	A107201	3-Amino-1,2,4-triazole	Analytical standard	Representative aminotriazole structure, used in acylation, condensation, hydrogen-bond construction, high-nitrogen heterocycle analysis, and structural reference studies
Basic triazole core intermediate	288-88-0	T100645	1,2,4-Triazole	≥99%	Basic 1,2,4-triazole core, used for N-position substitution, C-position modification, coordination structures, and synthesis of nitrogen-containing heterocyclic derivatives
N-Substituted triazole intermediate	6086-21-1	M139070	1-Methyl-1,2,4-triazole	≥99%	N-methylated triazole, used to study the effects of N-position substitution on polarity, basicity, coordination behavior, and downstream structural modification
Nitrotriazole intermediate	24807-55-4	N132858	3-Nitro-1,2,4-triazole	≥98% (HPLC)	Nitro-substituted high-nitrogen triazole, used in studies of electronic-effect regulation, reductive transformation, high-nitrogen structures, and thermal behavior
Aminotriazole intermediate	584-13-4	A107206	4-Amino-4H-1,2,4-triazole	≥98% (HPLC)	Amino-substituted triazole, used in heterocycle derivatization, acylation and condensation, hydrogen-bonding interactions, and coordination structure studies
Basic triazole core intermediate	288-36-8	H157233	1H-1,2,3-Triazole	≥98%	Basic 1,2,3-triazole core, used in studies of linker structures, substituent effects, tautomerism, and derivative construction
Diaminotriazole intermediate	1455-77-2	D132247	3,5-Diamino-1,2,4-triazole	≥98%	Diamino high-nitrogen heterocycle, used for multi-point hydrogen bonding, acylation and condensation, metal coordination, and construction of nitrogen-containing functional structures
N/S multi-site triazole intermediate	16691-43-3	A107449	3-Amino-5-mercapto-1,2,4-triazole	≥98%	Contains amino, mercapto, and triazole ring functionalities; used for multi-site coordination, surface adsorption, condensation reactions, and functionalization of sulfur-containing heterocycles
Mercaptotriazole intermediate	3179-31-5	M113506	3-Mercapto-1,2,4-triazole	≥97%	Representative mercaptotriazole structure, used in thioetherification, N/S multi-site coordination, metal surface interactions, and corrosion inhibition mechanism studies
Alkyl-substituted triazole intermediate	7343-34-2	D134424	3,5-Dimethyl-1,2,4-triazole	≥95% (GC)	Alkyl-substituted triazole, used in studies of substitution position, steric hindrance, lipophilicity, structural modification, and physicochemical property regulation

Table 3 Reagents Related to Click Chemistry and 1,2,3-Triazole Construction

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Cu(I) catalyst for copper-catalyzed azide–alkyne cycloaddition	7681-65-4	C433811	Copper(I) iodide	Anhydrous, ≥99.995% metals basis	Cu(I) catalyst used for azide–terminal alkyne cycloaddition to construct 1,4-disubstituted 1,2,3-triazole linker structures
Copper source for copper-catalyzed azide–alkyne cycloaddition	7758-99-8	C433966	Copper(II) sulfate pentahydrate	European Pharmacopoeia (Ph. Eur.), suitable for analysis, ACS, premium grade	Divalent copper salt source that can be combined with a reducing agent to generate the Cu(I) active species for triazole click cyclization systems
Reducing agent for copper-catalyzed azide–alkyne cycloaddition	134-03-2	S105025	Sodium ascorbate	Analytical standard	Reducing agent used to reduce Cu(II) to the Cu(I) active species and participate in the construction of azide–alkyne cycloaddition reaction systems
Cu(I) catalyst for copper-catalyzed azide–alkyne cycloaddition	7787-70-4	C104701	Copper(I) bromide	PrimorTrace™, ≥99.99% metals basis	Cu(I) catalyst used for cyclization of terminal alkynes with azide compounds to generate 1,2,3-triazoles
Alkynylation reagent	106-96-7	P106960	Propargyl bromide	80 wt% solution in toluene, containing 0.3% MgO stabilizer	Propargylation reagent used to introduce terminal alkyne structures and participate in triazole click linking and fragment conjugation
Electron-withdrawing alkyne substrate	623-47-2	E107738	Ethyl propiolate	≥98% (GC)	Electron-withdrawing alkynoate substrate, used to construct triazole carboxylate derivatives and study substituent electronic effects
Protected alkyne reagent	1066-54-2	E106615	(Trimethylsilyl)acetylene	≥98%	Protected acetylene reagent, used for preparation of terminal alkyne precursors, alkyne introduction, and construction of triazole linker structures
Amino alkyne substrate	2450-71-7	p103552	Propargylamine	≥98%	Amino-containing terminal alkyne reagent, used to introduce alkynyl fragments that can be further modified, participate in click cyclization, and undergo downstream functional-group transformations
Electron-withdrawing alkyne substrate	922-67-8	M106792	Methyl propiolate	≥97%	Electron-withdrawing alkynoate substrate, used for synthesis of triazole carboxylate structures, comparison of electronic effects, and intermediate derivatization
Aryl alkyne substrate	536-74-3	P107030	Phenylacetylene	≥97%	Aryl terminal alkyne substrate, used for synthesis of aryl-substituted 1,2,3-triazoles and studies of fragment-linking structures
Azide substrate	72320-38-8	A464136	3-Azido-1-propanol	≥96%	Azido-terminated alcohol, used to introduce azido functional groups, enable click linking, conduct terminal modification, and construct triazoles through post-cyclization routes
Copper ligand for copper-catalyzed azide–alkyne cycloaddition	510758-28-8	T162437	Tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA)	≥95%	Triazole-type copper ligand used to stabilize the Cu(I) active species and improve the controllability of azide–alkyne cycloaddition systems

Table 4 Benzotriazole Derivatives and Carboxylic Acid-Activating Coupling Reagents

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Azabenzotriazole carboxylic acid activation reagent	39968-33-7	H109328	1-Hydroxy-7-azabenzotriazole (HOAt)	≥99%	Azabenzotriazole hydroxy reagent used for carboxylic acid activation, amide coupling, peptide synthesis, and studies on racemization control
Benzotriazole carboxylic acid activation reagent	2592-95-2	H684271	1-Hydroxybenzotriazole (HOBt)	≥99%	Benzotriazole hydroxy reagent used to form activated ester structures and participate in carboxylic acid activation, amide coupling, and peptide synthesis
Methylbenzotriazole derivative	136-85-6	M158122	5-Methyl-1H-benzotriazole	≥99%	Methyl-substituted benzotriazole, used in studies of substituent effects, metal surface interactions, coordination behavior, and protective systems
Azabenzotriazole uronium coupling reagent	148893-10-1	H109327	O-(7-Azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HATU)	≥99%	Azabenzotriazole-type uronium coupling reagent used for carboxylic acid activation, amide bond construction, peptide synthesis, and pharmaceutical intermediate coupling
Benzotriazole uronium coupling reagent	94790-37-1	H106174	O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU)	≥99%	Benzotriazole-type uronium coupling reagent used for carboxylic acid activation, amide bond construction, peptide condensation, and preparation of heterocyclic intermediates
Benzotriazole core derivative	95-14-7	B101002	Benzotriazole	≥99%	Basic benzotriazole structure, used in metal surface adsorption, coordination interactions, protective systems, and construction of benzotriazole derivatives
Methylbenzotriazole mixture	29385-43-1	M158120	Methyl-1H-benzotriazole, mixture (TTA)	≥98% (GC)	Mixture of methylbenzotriazole isomers, used in metal surface protection, substituent-effect studies, and corrosion inhibition systems
N-Substituted benzotriazole derivative	13351-73-0	M158121	1-Methyl-1H-benzotriazole	≥98%	N-methylated benzotriazole, used to compare the effects of N-position substitution on adsorption, coordination, and surface interactions
Halogenated benzotriazole derivative	94-97-3	C153445	5-Chlorobenzotriazole	≥98%	Halogenated benzotriazole, used in studies of electron-withdrawing substituent effects, downstream functional modification, and metal surface interactions
Benzotriazole uronium coupling reagent	125700-67-6	T109338	O-(Benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate	≥98%	Benzotriazole-type uronium coupling reagent used for carboxylic acid activation, amide coupling, peptide synthesis, and preparation of heterocyclic intermediates
Benzotriazole phosphonium coupling reagent	56602-33-6	B106161	BOP Reagent	≥98%	Benzotriazole-type phosphonium coupling reagent used for carboxylic acid activation, peptide condensation, amide bond construction, and intermediate coupling
Benzotriazole carboxylic acid activation reagent	123333-53-9	H106176	1-Hydroxybenzotriazole monohydrate	≥97%	Hydrated benzotriazole hydroxy reagent used for carboxylic acid activation, amide coupling, peptide synthesis, and activated ester studies
Hydroxymethyl benzotriazole derivative	28539-02-8	H183428	1H-Benzotriazol-1-ylmethanol	≥96%	Hydroxymethylated benzotriazole, used in functional modification, resin additives, surface interactions, and benzotriazole derivative studies

Table 5 Triazole Agrochemical Analytical Standards and Active Reference Compounds

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Triazole agrochemical analytical standard	60207-90-1	T114972	Propiconazole	Analytical standard, mixture of isomers	Triazole-class fungicide analytical standard used for pesticide residue detection, sterol biosynthesis inhibition studies, and resistance monitoring
Triazole agrochemical standard solution	43121-43-3	T109948	Triadimefon standard solution	Analytical standard, 10 µg/mL in petroleum ether	Triazole-class fungicide standard solution used for residue analysis, method validation, instrument calibration, and detection of sterol synthesis inhibitors
Triazole plant growth regulator standard solution	76738-62-0	P109934	Paclobutrazol standard solution	Analytical standard, 10 µg/mL in methanol	Triazole-class plant growth regulator standard solution used for crop growth regulation studies, residue analysis, and quality control
Triazole agrochemical standard solution	85509-19-9	F109957	Flusilazole standard solution	Analytical standard, 1.00 mg/mL in methanol	Triazole-class fungicide standard solution used for pesticide residue detection, instrument calibration, analytical method development, and resistance monitoring
Triazole agrochemical analytical standard	131983-72-7	T114742	Triticonazole	Analytical standard, ≥99.2%	Triazole-class fungicide analytical standard used for seed treatment agent analysis, crop disease control studies, and residue detection
Triazole agrochemical analytical standard	107534-96-3	T110039	Tebuconazole	Analytical standard, ≥99%	Triazole-class fungicide analytical standard used for pesticide residue detection, sterol demethylation inhibition studies, and resistance risk assessment
Triazole agrochemical analytical standard	88671-89-0	M117283	Myclobutanil	Analytical standard, ≥98.5%	Triazole-class fungicide analytical standard used for crop disease control studies, residue analysis, and target mechanism studies
Triazole agrochemical analytical standard	79983-71-4	H109963	Hexaconazole	Analytical standard, ≥98%	Triazole-class fungicide analytical standard used for pesticide residue detection, quality control, and inhibition studies of pathogenic fungi
Triazole agrochemical analytical standard	119446-68-3	D109735	Difenoconazole	Analytical standard, ≥98%	Triazole-class fungicide analytical standard used for pesticide residue detection, sterol demethylation inhibition studies, and resistance monitoring
Triazole plant growth regulator analytical standard	83657-22-1	U114871	Uniconazole	Analytical standard, ≥97.5%	Triazole-class plant growth regulator analytical standard used for gibberellin biosynthesis-related studies, residue analysis, and quality control
Triazole agrochemical active compound	66246-88-6	P769212	Penconazole	Moligand™, ≥98%	Triazole-class fungicidal active compound used for sterol demethylation inhibition, agrochemical activity evaluation, and resistance mechanism studies
Triazole agrochemical analytical standard	133855-98-8	E695490	Epoxiconazole	Analytical standard	Triazole-class fungicide analytical standard used for cereal disease control studies, residue detection, and analytical method development
Triazole agrochemical active compound	76674-21-0	F1421303	Flutriafol	≥98%	Triazole-class fungicidal active compound used for sterol demethylation inhibition, crop disease control, and structure–activity relationship studies

Table 6 Triazole Pharmaceutical Active Compounds and Mechanism Reference Compounds

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Triazole antifungal active compound	171228-49-2	P125008	Posaconazole	Moligand™, ≥99%	Triazole-class antifungal active compound used for sterol biosynthesis inhibition, resistance mechanism studies, and drug activity research
Triazole aromatase inhibitor	120511-73-1	A126470	Anastrozole	Moligand™, ≥99%	Triazole-class aromatase inhibitor used in studies of metalloenzyme inhibition, pharmacophore structure–activity relationships, and endocrine pharmacology
Triazole antifungal active compound	84625-61-6	I129771	Itraconazole	Moligand™, ≥98% (HPLC)	Triazole-class antifungal active compound used for sterol synthesis pathway inhibition, fungal resistance studies, and drug metabolism research
Triazole antifungal active compound	137234-62-9	V129745	Voriconazole	Moligand™, ≥98%	Triazole-class antifungal active compound used in studies of invasive fungal infections, target enzyme inhibition, and drug susceptibility evaluation
Triazole nucleoside analog	36791-04-5	R101754	Ribavirin	Moligand™, ≥98%	1,2,4-Triazole carboxamide nucleoside analog used for antiviral activity, nucleoside metabolism, and drug mechanism studies
Triazole aromatase inhibitor	112809-51-5	L129473	Letrozole (CGS 20267)	Moligand™, ≥98%	Triazole-class aromatase inhibitor used in studies of interactions with heme metal centers, endocrine pharmacology, and pharmacological effects
Triazole antifungal active compound	86386-73-4	E129360	Fluconazole	Moligand™, ≥98%	Triazole-class antifungal active compound used for sterol demethylase inhibition, drug susceptibility studies, and fungal resistance research
Triazole antifungal active compound	241479-67-4	I337027	Isavuconazole	≥98%	Triazole-class antifungal active compound used for sterol biosynthesis inhibition, resistant strain studies, and drug activity research

Note: The above products are representative Aladdin products related to scientific research and formulation studies. For more information on product specifications, grades, and COA, please search by product name, CAS number, or catalog number on the Aladdin website.

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