Technical articles

What Is Pyrazine? Structural Features, Naming Clarification, Application Scenarios, and a Reagent Selection Roadmap (with Product Tables 1–4)

1.Why do we keep encountering pyrazines in “drugs, materials, and food aroma”?

 

When you smell the characteristic “roasted / nutty / toasty” notes in coffee, roasted nuts, or cocoa powder, a common group of key volatile compounds behind that aroma is alkyl-substituted pyrazines (alkylpyrazines). They are generated in large amounts during thermal processing such as the Maillard reaction, and they can make a substantial contribution to flavor.

 

In research and industry, pyrazine is also a classic nitrogen-containing aromatic heterocycle: it can serve as a tunable electronic module in drug molecules, and it can also act as a nitrogen donor / bridging unit in coordination chemistry and materials chemistry.

 

A very intuitive example is the frontline antituberculosis drug pyrazinamide (PZA), which contains a pyrazine ring and is one of the key drugs in combination TB therapy. Its distinctive value is often associated with “sterilizing activity” against tolerant or non-replicating bacterial populations in acidic / inflammatory microenvironments at lesion sites. For this reason, it is widely regarded as one of the important components that help shorten treatment duration in standard regimens.

 

2.What exactly do pyrazine and “paradiazines” correspond to?

1. Pyrazine is a six-membered aromatic heterocycle with two nitrogen atoms positioned para to each other (1,4-positions).

 

 

 

2. Because the two nitrogen atoms are in a para relationship, pyrazine can also be written as 1,4-diazine or p-diazine (para-diazabenzene). In databases and older literature, you may also see spellings such as paradiazine (Paradiazine), but modern textbooks and papers more commonly use pyrazine / 1,4-diazine.

 

3. It is important to distinguish this clearly: “diazines” are not limited to pyrazine. They also include two other positional isomers:

a) 1,2-diazine: pyridazine

b) 1,3-diazine: pyrimidine

c) 1,4-diazine: pyrazine

 

Common English Name

N Positions (Numbering)

Common Aliases / Notes

One-Sentence Identifier

Pyridazine

1,2-Diazine

ortho-diazine (1,2-diazabenzene)

Two N atoms adjacent (1,2).

Pyrimidine

1,3-Diazine

meta-diazine (1,3-diazabenzene)

Two N atoms separated by one carbon (1,3).

Pyrazine

1,4-Diazine

para-diazine (1,4-diazabenzene); p-Diazine / para-Diazine / Paradiazine

Two N atoms opposite each other (1,4).

 

3.Structural features of pyrazine

 

The key structural takeaways for pyrazine can be captured in three points:

1. “Two nitrogens make the ring more electron-deficient.”

The two ring nitrogens collectively withdraw electron density from the aromatic ring, giving pyrazine an electron-deficient character.

2. “Therefore, it is a weak base and more often behaves as an ‘acceptor.’”

The lone pairs on aromatic nitrogens can accept a proton or coordinate to metals. However, due to the inductive/withdrawal effect from two nitrogens, pyrazine is typically much less basic than pyridine (pyrazine conjugate acid pKa ≈ 0.6, pyridine conjugate acid pKa ≈ 5.2; values may vary slightly with solvent and ionic strength). As a result, pyrazine more often participates in molecular recognition as a hydrogen-bond acceptor / coordination acceptor.

3. “Two nitrogens = two handles: coordination and architecture are designable.”

Pyrazine can act as a monodentate ligand, and it also frequently serves as a bridging bidentate ligand that “links” two metal centers, enabling the construction of coordination polymers, molecular wire-like architectures, or other functional materials.

 

4.What are the characteristics of pyrazine-related products?

 

Pyrazine reagents are not only important—they belong to a heterocycle family with high reuse across disciplines. From the practical perspective of buying reagents and doing research, pyrazine-related products commonly share these traits:

 

1. High value as a general scaffold: the pyrazine ring is a reusable module for molecular design, applicable to drug leads as well as materials and coordination systems.

2. Large derivatization space: introducing functional groups such as halogens, amino, carboxyl, cyano, etc., quickly turns pyrazine into building blocks that are cross-coupling-ready, substitution-ready, salt-formable, and coordination-capable.

3. Clear and predictable electronic effects: its electron deficiency makes certain substitution strategies and interaction designs more predictable and “computable.”

4. Broad “real-world landing zones” in applications: three mature main lines—food aroma (roasted flavors), pharmaceuticals (a representative antituberculosis drug), and coordination/materials (bridging units and electron-acceptor fragments)—all support widespread use.

 

5.How to Classify Pyrazine-Related Products

 

Product Category (by Use)

Representative Examples

Key Structural / Property Clues

Typical Uses (Research Tasks)

Parent core & simply substituted pyrazines

Pyrazine; methyl/ethyl/dimethyl pyrazines (alkylpyrazines)

Basic 1,4-diazine aromatic ring; alkyl substitution often increases volatility and enhances flavor impact

Basic physicochemical benchmarks; food flavor/volatile studies (Maillard reaction, GC–MS fingerprinting)

Further functionalizable “building blocks”

Halopyrazines (chloro/bromo/fluoro); aminopyrazines

Reactive “handles” (halogens, NH, etc.) for coupling/substitution

Heterocycle assembly; medicinal-chemistry lead synthesis; compound library construction

Polar derivatives (tuning solubility / salt formation)

Pyrazine carboxylic acids; pyrazine carboxamides (e.g., pyrazinamide-type)

COH/CONH increase polarity, facilitate salt formation, and improve solubility

Salt form / solubility optimization; drug-related studies; metabolism and analytical method development

N-oxides & electronic-effect tuning

Pyrazine N-oxide, etc.

N→O alters electron distribution and coordination/reactivity features

Reaction-mechanism studies; electronic-effect tuning in coordination chemistry/materials

Fused systems (expanded π systems)

Quinoxaline (benzopyrazine), etc.

Larger π system, often stronger conjugation and richer properties

Lead scaffolds in drug discovery; optoelectronic/functional materials; coordination assembly

Standards for analysis / quantitation

Isotopically labeled pyrazines (e.g., pyrazine-d)

Suitable as internal standards to improve GC/LC–MS quantitation reliability

Quantitation/traceability for flavoromics, metabolomics, and quality control

 

6.Typical applications of pyrazine: turning “structural features” into real scenarios

6.1 Food and aroma chemistry: a “key puzzle piece” of roasted flavors

1. Many pyrazine derivatives occur in baked, roasted, and stir-fried foods, and are closely associated with nutty, roasted, cocoa, and cereal aroma notes.

2. Common research tasks include: elucidating Maillard reaction pathways, regulating flavor formation, GC–MS quantitation, and flavor fingerprinting.

 

6.2 Medicinal chemistry and anti-infectives: from scaffold to real clinical drugs

1. Pyrazinamide (PZA) is one of the key drugs in combination therapy for tuberculosis, with distinctive mechanistic significance against non-replicating / persister-state Mycobacterium tuberculosis. The classic view is that PZA must be activated by the bacterial pncA/pyrazinamidase to pyrazinoic acid (POA) in order to exert activity; the downstream steps are considered complex and continue to be refined (different studies emphasize different targets/pathways).

2. The pyrazine ring itself is often used as a fragment that can provide hydrogen-bond acceptors, tunable electronics, and tunable polarity, helping a molecule balance target binding with physicochemical properties.

 

6.3 Coordination chemistry and materials: two nitrogens make it a master of “bridging and assembly”

Pyrazine can coordinate to metals in monodentate or bridging modes, building polynuclear complexes, coordination polymers, or electronically coupled systems. It is a common “linker” in inorganic and materials research.

 

6.4 Natural products and pharmacology: a representative example—tetramethylpyrazine (TMP/ligustrazine)

Tetramethylpyrazine (TMP, ligustrazine) is a representative pyrazine-derived natural constituent found in Ligusticum chuanxiong (Chuanxiong) and related sources, and there is substantial review literature discussing its pharmacological mechanisms and clinical applications.

 

7.Safety and storage essentials

Pyrazine and some of its derivatives may be irritating and somewhat volatile. In flavor/volatile experiments in particular, pay close attention to airtight sealing, low-temperature storage, light protection, adequate ventilation, and personal protective equipment (PPE). Isotope-labeled standards also often come with explicit hazard classification statements.

 

8.Product Navigation Table | Quickly Locate Pyrazine-Related Standards, Building Blocks, and Ligands by Research Task / Experimental Need (corresponding to Tables 1–4)

 

Research Task / Experimental Need

Key Structural / Property Clues to Look For

Recommended Table(s) to Check First

What You Can Find in the Table

Quantify volatiles and aroma in foods/flavors/spirits (GC–MS / GC–O)

Focus on alkylpyrazines (roasted/nutty notes) and methoxypyrazines (green bell pepper/herbal; extremely low odor thresholds). Using IBMP as an example, the sensory threshold in water can reach the ng/L range; thresholds vary across matrices and systems. Use isotopically labeled internal standards to improve quantitative reliability.

Table 1

2-methyl, dimethyl, trimethyl, tetramethyl, ethyl / ethyl-methyl / ethyl-dimethyl pyrazines; 2-acetylpyrazine; methoxypyrazines (IBMP / IPMP / 2-methoxy-6-methyl); the pyrazine parent core and pyrazine-d4 internal standard

Develop / validate GC or LC methods (retention time, response factor, linearity, recovery)

Prioritize a set that spans polarity/volatility: parent core + representative substituted analogs; add an internal standard for absolute quantitation

Mainly Table 1

A “calibration-curve set” from parent pyrazine to typical flavor pyrazines and methoxypyrazines; pyrazine-d4 for correcting matrix effects and instrument drift

Rapid derivatization / substitution-site exploration on the pyrazine scaffold (SNAr; one-pot introduction of amines/thiols/alcohols, etc.)

Choose chloropyrazines / polychloropyrazines (more suitable for SNAr); select the platform by desired substitution pattern: 2-, 2,3-, 2,5-, 2,6-, and tetrachloro platforms

Table 2

“Electrophilic chassis” such as 2-chloro, 2,3-dichloro, 2,5-dichloro, 2,6-dichloro, and tetrachloropyrazine for building substituted-pyrazine libraries

Build libraries via cross-coupling (Suzuki / Negishi / Buchwald, etc.)

Bromopyrazines / dibromopyrazines are broadly applicable; for directly attaching a pyrazin-2-yl group to aryl/heteroaryl rings, consider boronic acids

Table 2 (halogenated) + Table 3 (boronic acids)

2-bromo, 2,5-dibromo, 2,6-dibromopyrazine; and (pyrazin-2-yl)boronic acid (commonly used for Suzuki coupling)

Need a “functional handle” for continued transformations (amide formation / reductive amination / hydrolysis / coordination)

For amides: choose pyrazine carboxylic acids / diacids; for reductive amination / Schiff bases: choose pyrazine-2-carboxaldehyde; for electronic tuning or further conversion: consider cyano and N-oxides

Table 3

2-pyrazinecarboxylic acid, its methyl ester, 2-carboxaldehyde, 2-cyano, pyrazine N-oxide / 1,4-dioxide; plus multi-carboxylic-acid series

MOFs / coordination polymers / metal complexation (need N sites + carboxylate anchors / high connectivity)

For linkers, choose diacids / tetracarboxylic acids (higher connectivity and more rigid frameworks); for strong acceptor character / tunable electronics, consider N-oxides

Mainly Table 3 + Table 4 (ligand expansion)

MOF linkers such as pyrazine-2,3-/2,5-/2,6-dicarboxylic acids and pyrazine tetracarboxylic acid; ligand expansion options in Table 4 (bipyrazine, multi-pyridyl ligands)

Transition-metal complexes / luminescence / electrochemical materials (multiple N-coordination sites)

For polydentate N ligands, prioritize bipyrazine or tetra(2-pyridyl)pyrazine to build chelating/self-assembled systems

Table 4

Multi-nitrogen ligands such as 2,2′-bipyrazine and tetra(2-pyridyl)pyrazine for coordination complexes and photophysical/electrochemical studies

Quinoxaline / fused diaza-aromatic systems (medicinal chemistry / materials)

Target is not mono-pyrazine but fused rings (quinoxaline) and derivatives such as carboxylic acids, dihydroxy, and N-oxides

Table 4

Quinoxaline core and derivatives including 2-quinoxalinecarboxylic acid, 2,3-dihydroxyquinoxaline, and quinoxaline 1,4-dioxide

Drug analysis / activity references / control experiments (pyrazine-containing drugs)

Need high-purity reference standards; check salt form / hydrate (affects weighing and solubility). Match internal standards or close analogs to your analytical platform

Mainly Table 4 + Table 1 (method / internal-standard support)

References such as favipiravir, pyrazinamide, amiloride hydrochloride hydrate; plus Table 1 parent-core / internal-standard support for method validation

 

Table 1 | Aroma / Volatile Standards: Alkylpyrazines, Methoxypyrazines, and the Parent Core / Internal Standard (Common for GC–MS / GC–O)

 

Category

CAS No.

Aladdin Cat. No.

Name

Specification / Purity

Key Features & Applications

Parent pyrazine core (basic reference)

290-37-9

P109613

Pyrazine

≥99%

Fundamental pyrazine core; used as a method-development reference (GC/LC), a starting material for synthesis routes, and a model system for heteroaromatic electronic/coordination studies

Parent pyrazine core (isotopic internal standard)

1758-62-9

P346218

Pyrazine-d4

≥98 atom% D, ≥98%

Stable-isotope internal standard; used for GC/LC–MS quantitation of pyrazine and derivatives, correcting matrix effects, recovery, and instrument drift

Flavor alkylpyrazines (aroma/volatile standards)

109-08-0

M158369

2-Methylpyrazine

≥98% (GC)

Common roasted/nutty volatile; used for GC–MS method setup, aroma quantitation, and reaction-formation pathway studies

Flavor alkylpyrazines (aroma/volatile standards)

5910-89-4

D106292

2,3-Dimethylpyrazine

≥98%

Representative roasted/nutty compound; used as a reference in food flavor research, fragrance formulation, and GC–MS qualitative/quantitative analysis

Flavor alkylpyrazines (aroma/volatile standards)

123-32-0

D106345

2,5-Dimethylpyrazine

≥98%

Common component in roasted aroma profiles; used in flavoromics/flavor quantitation and for building standard spectral libraries

Flavor alkylpyrazines (aroma/volatile standards)

108-50-9

D154789

2,6-Dimethylpyrazine

≥98% (GC)

Common roasted note contributor; used as a reference for food/flavor volatile analysis and heated reaction systems (Maillard chemistry)

Flavor alkylpyrazines (aroma/volatile standards)

14667-55-1

T106601

2,3,5-Trimethylpyrazine

≥99%

Typical “roasted/toasty” flavor molecule; standard for food flavor and baked/coffee volatile profiling

Flavor alkylpyrazines (aroma/volatile standards)

1124-11-4

T111263

2,3,5,6-Tetramethylpyrazine

≥98%

Classic roasted-aroma component; used for flavor-chemistry standards and volatile spectral library building (especially in baked/coffee samples)

Flavor alkylpyrazines (aroma/volatile standards)

13925-00-3

E156371

2-Ethylpyrazine

≥99% (GC)

Common roasted/nutty volatile; standard for aroma profiling (GC–MS/GC–O) and flavor formulation studies

Flavor alkylpyrazines (aroma/volatile standards)

15707-23-0

E105685

2-Ethyl-3-methylpyrazine

≥99%

One of the key roasted/nutty contributors; reference for aroma quantitation and heated reaction (Maillard) system studies

Flavor alkylpyrazines (aroma analysis standard)

27043-05-6

E133774

2-Ethyl-3,5(6)-dimethylpyrazine

Analytical standard; isomeric mixture

Typical “roasted/nutty/cocoa” aroma component; used as a GC–MS qualitative/quantitative reference (isomeric mixture is closer to real samples)

Functionalized flavor pyrazines (carbonyl handle)

22047-25-2

A100996

2-Acetylpyrazine

≥99%

Signature Maillard aroma marker; used in flavor research. The carbonyl group is also convenient for derivatization (condensation, reduction, etc.)

Methoxypyrazines (green/herbal trace standards)

2882-21-5

M697884

2-Methoxy-6-methylpyrazine

≥97%

Pronounced “green/herbal” odor; standard for trace-aroma analysis and studies of sensory threshold / release behavior

Methoxypyrazines (green/herbal trace standards)

25773-40-4

I135731

2-Isopropyl-3-methoxypyrazine

≥98% (GC)

Key “green bell pepper/grass” odorant; used for trace quantitation and sensory-correlation studies in wines and fruits/vegetables

Methoxypyrazines (green/herbal trace standards)

24683-00-9

I137130

2-Isobutyl-3-methoxypyrazine

≥99%

Extremely low-threshold “green/herbal” odor source; widely used standard for trace volatile analysis (GC–MS/GC–O) in wines and agricultural products

 

Table 2 | Halogenated / Highly Halogenated Pyrazines: Electrophilic Building Blocks for SNAr and Cross-Coupling (Rapid Assembly of Substituted Pyrazines)

 

Category

CAS No.

Aladdin Cat. No.

Name

Specification / Purity

Key Features & Applications

Halopyrazines (electrophilic building blocks)

14508-49-7

C124227

2-Chloropyrazine

≥98%

A classic halopyrazine starting material; used for SNAr to introduce amines/alcohols/thiols, or for coupling reactions to build substituted pyrazines

Halopyrazines (electrophilic building blocks)

56423-63-3

B135014

2-Bromopyrazine

≥97%

The bromo site is well-suited for Pd-catalyzed couplings (Suzuki/Buchwald, etc.); commonly used to build 2-substituted pyrazine libraries

Halopyrazines (electrophilic building blocks)

4858-85-9

D123437

2,3-Dichloropyrazine

≥98% (GC)

Electron-poor halopyrazine suitable for SNAr substitution or cross-coupling; enables rapid access to 2,3-disubstituted pyrazine scaffolds

Halopyrazines (electrophilic building blocks)

19745-07-4

D175458

2,5-Dichloropyrazine

≥97%

Used for selective SNAr or cross-coupling to quickly enter 2,5-disubstituted pyrazine series (common in lead molecules/materials motifs)

Halopyrazines (electrophilic building blocks)

4774-14-5

D123438

2,6-Dichloropyrazine

≥98%

Suitable for selective SNAr substitution or coupling; used to build 2,6-disubstituted pyrazines (a common linkage pattern in medicinal chemistry/materials)

Halopyrazines (electrophilic building blocks)

23229-26-7

D154926

2,5-Dibromopyrazine

≥98% (GC)

Bromo sites facilitate Suzuki/Negishi and related couplings; used to construct 2,5-disubstituted pyrazines and multi-substituted heteroaromatic frameworks

Halopyrazines (electrophilic building blocks)

23229-25-6

D138534

2,6-Dibromopyrazine

≥95%

Well-suited for dual-site cross-coupling to build symmetric or 2,6-disubstituted pyrazines; often used for extending materials/ligand backbones

Highly halogenated pyrazines (SNAr platform)

13484-50-9

P587029

Perchloropyrazine

≥97%

Strongly electron-withdrawing, multi-chloro platform for stepwise SNAr; enables rapid introduction of amines/thiols/alcohols to build highly substituted pyrazine scaffolds

 

Table 3 | Functionalized Pyrazine Building Blocks: Amino / Cyano / Aldehyde / Carboxylic Acid (Ester) / N-Oxides and Polycarboxylic Acids (High-Frequency in Synthesis & Coordination Studies)

 

Category

CAS No.

Aladdin Cat. No.

Name

Specification / Purity

Key Features & Applications

Aminopyrazines (amination platform)

5049-61-6

A111242

Aminopyrazine

≥99%

A commonly used N-heteroaryl amine building block; easy to acylate/sulfonylate/cyclize, introduces H-bonding sites; a high-frequency intermediate in medicinal chemistry

Aminopyrazines (multi-amine building blocks)

13134-31-1

D190531

2,3-Diaminopyrazine

≥97%

Two amine sites enable acylation/cyclization/condensation and multiple H-bond interactions; widely used in medicinal chemistry and coordination-ligand construction

Aminopyrazines (multi-amine building blocks)

41536-80-5

D303681

2,6-Diaminopyrazine

≥95%

2,6-diamine pattern facilitates bifunctionalization and ring formation; used to build multi-H-bond fragments in medicinal chemistry or as an N,N-coordination building unit

Functionalized pyrazine building blocks (cyano)

19847-12-2

P121629

Pyrazinecarbonitrile

≥99%

Strong electron-withdrawing group for tuning scaffold electronics; nitrile can be further hydrolyzed/reduced, etc.; commonly used in pharma/agrochemical building-block synthesis

Functionalized pyrazine building blocks (aldehyde)

5780-66-5

P176847

Pyrazine-2-carbaldehyde

≥97%

Aldehyde enables reductive amination/condensation (Schiff base) and construction of pyrazine-containing ligands; frequently used in medicinal and coordination chemistry derivatization

Functionalized pyrazine building blocks (monocarboxylic acid)

98-97-5

P106883

2-Pyrazinecarboxylic acid

≥98%

Common pyrazine-carboxylic-acid fragment; used for amide coupling with amines (high-frequency in medicinal chemistry) and also as a coordination/chelation anchor

Functionalized pyrazine building blocks (carboxylate ester)

6164-79-0

M158371

Methyl 2-Pyrazinecarboxylate

≥97% (GC)

Ester supports downstream hydrolysis/transesterification/amide formation; used as a synthetic intermediate to introduce pyrazine-2-carbonyl fragments

Core derivatives (N-oxide)

2423-65-6

P168941

Pyrazine N-oxide

≥97%

Common intermediate and electronic-effect model; used to study how N-oxidation affects heteroaromatic reactivity/coordination, and as a precursor for further substitution

Core derivatives (di-N-oxide)

2423-84-9

P348162

Pyrazine 1,4-Dioxide

≥95%

Dual N-oxidation enhances electron-acceptor character; used in redox/electronic-structure studies and as a precursor for further reduction or substitution

Pyrazine polycarboxylic acids (ligands / MOF linkers)

122-05-4

P163010

Pyrazine-2,5-dicarboxylic acid

≥97%

Dicarboxylic acid provides multidentate coordination and a rigid backbone; widely used as a linker in MOFs/coordination polymers and in metal-complex studies

Pyrazine polycarboxylic acids (ligands / MOF linkers)

940-07-8

P195960

Pyrazine-2,6-dicarboxylic acid

≥95%

Linear, rigid dicarboxylate linker; often used to build MOFs/coordination polymers with regular channels and for metal complexation and structure–property studies

Pyrazine polycarboxylic acids (ligands / MOF linkers)

89-01-0

P100816

2,3-Pyrazinedicarboxylic acid

≥97%

Ortho-dicarboxylation strengthens multi-point coordination; used in metal complexation, MOF/coordination-polymer construction, and tuning via acidic functional groups

Pyrazine polycarboxylic acids (high-connectivity ligands)

43193-60-8

P701479

Pyrazinetetracarboxylic acid

≥97%

Multiple carboxylates provide high connectivity and strong coordination; commonly used for MOFs/coordination networks, metal-ion chelation, and porous-material construction

Coupling reagent (pyrazine boronic acid)

762263-64-9

B634503

(Pyrazin-2-yl)boronic acid (contains varying amounts of anhydride)

≥97%

Common Suzuki coupling reagent; used to incorporate a “pyrazin-2-yl” unit into aryl/heteroaryl systems for rapid construction of medicinal-chemistry/materials frameworks

 

Table 4 | Drugs, Fused-Ring Derivatives, and Coordination Ligands: Bioactive References, Quinoxaline Series, and Polynitrogen Ligands

 

Category

CAS No.

Aladdin Cat. No.

Name

Specification / Purity

Key Features & Applications

Pyrazine-based drugs / bioactive references

259793-96-9

F303252

Favipiravir

Moligand™, ≥99%

An antiviral small molecule containing a pyrazine scaffold; reference material for analytical method development, quality control, and in vitro activity/metabolism studies

Pyrazine-based drugs / bioactive references

98-96-4

P129219

Pyrazinamide

Moligand™, ≥98%

Classic antitubercular pyrazinamide; commonly used as a reference in quantitative drug analysis, dissolution/stability studies, and metabolism-related experiments

Pyrazine-based drugs / biological probes

2016-88-8

A131615

Amiloride hydrochloride hydrate

≥98%

An ion-transport inhibitor containing a pyrazine ring; widely used as a tool compound and method reference in cellular physiology (e.g., ENaC/NHE-related pathways)

Quinoxaline scaffold (fused diaza-aromatic)

91-19-0

Q160826

Quinoxaline

≥99% (GC)

Common fused diaza-aromatic scaffold; used in medicinal/materials chemistry (electron acceptor, luminescent scaffold) and as a synthesis-intermediate reference

Quinoxaline derivatives (hydroxylated)

15804-19-0

D123522

2,3-Dihydroxyquinoxaline

≥98%

A 2,3-dihydroxy fused diaza-aromatic; used as a synthetic intermediate and to study how substitution affects electronic/coordination properties of fused systems

Quinoxaline derivatives (carboxylic-acid building block)

879-65-2

Q113505

2-Quinoxalinecarboxylic acid

≥97%

“Dual-handle” fused diaza-aromatic + carboxylic acid; used for amide coupling to introduce drug fragments or as a coordination anchor for complex studies

Quinoxaline derivatives (N-oxide fused system)

2423-66-7

Q404967

Quinoxaline 1,4-Dioxide

≥95%

N-oxide fused structure; used in drug-activity screening and redox/electronic-effect studies, and as a precursor for further fused-ring derivatization

Pyrazine ligands for coordination/materials (bipyrazine)

10199-00-5

B152418

2,2'-Bipyrazine

≥97% (GC)

Bipyrazine N,N-coordination fragment; commonly used in transition-metal complexes, coordination polymers/MOFs, and electrochemical/photophysical studies

Polydentate ligands for coordination/materials

25005-97-4

T337877

Tetra-2-pyridinylpyrazine

≥94%

Strong chelating ligand with multiple N sites; used for transition-metal complexes, luminescent/electrochemical materials, and coordination self-assembly (a typical “multi-pyridyl” ligand type)

 

Note: The products above are representative items from Aladdin. For additional specifications, please refer to the full product list at the end of the article, or search the Aladdin website using the product name / CAS / catalog number.

 

For more related articles, please see below:

 

Pyridinones as “Property Knobs” in Drug Design: From Tautomers and H-Bonding Fingerprints to Product Selection (Tables A–C)

 

From Piperidine to Pyridine: The “Most Common N-Heterocycle” Shift in FDA Small-Molecule New Drugs (2013–2023) and a Selection Guide (Tables 1–4)

 

2-Methylpyridine–Borane (2-Picoline·BH) Reductive Amination Guide: Process Drivers for Replacing NaBHCN, the Practical Operating Window, and Scale-Up/Quench Close-Out Essentials (Including Product Tables 1–3)

Categories: Technical articles

Da — when not otherwise indicated, molecular weight units are daltons.   Mw — weight-average molecular weight.   Mn — number-average molecular weight.

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Cite this article

Aladdin Scientific. "What Is Pyrazine? Structural Features, Naming Clarification, Application Scenarios, and a Reagent Selection Roadmap (with Product Tables 1–4)" Aladdin Knowledge Base, updated Mar 10, 2026. https://www.aladdinsci.com/us_en/faqs/what-is-pyrazine-structural-features-naming-clarification-application-scenarios-en.html
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