Pyrazines|Pyrazine derivatives preparation supplier|Wealsun Biotech https://wealsunbio.com/product-category/pyrazines/ Mon, 23 Feb 2026 13:11:46 +0000 en-US hourly 1 https://wordpress.org/?v=7.0 https://wealsunbio.com/wp-content/uploads/2025/06/20260211161228_5028_5-e1770797653670.png Pyrazines|Pyrazine derivatives preparation supplier|Wealsun Biotech https://wealsunbio.com/product-category/pyrazines/ 32 32 5-CHLORO-PYRAZINE-2-CARBOXYLIC ACID https://wealsunbio.com/product/5-chloro-pyrazine-2-carboxylic-acid/ https://wealsunbio.com/product/5-chloro-pyrazine-2-carboxylic-acid/#respond Sat, 24 Jan 2026 12:14:19 +0000 https://wealsunbio.com/?post_type=product&p=22232 5-Chloropyrazine-2-carboxylic acid (CAS 36070-80-1) is a strategically bifunctional pyrazine scaffold engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and agrochemical development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with a chlorine substituent at the C5 position and a carboxylic acid group at the C2 position. The C2-carboxylic acid moiety serves as a versatile handle for amide coupling, esterification, or salt formation, while the C5-chloro handle is activated by the adjacent ring nitrogen, enabling efficient nucleophilic aromatic substitution (SNAr) or Pd-catalyzed cross-coupling (Suzuki, Buchwald-Hartwig). This dual-functionality architecture enables orthogonal derivatization strategies, making it particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and agrochemical actives where the chloroacid-pyrazine motif balances electron-deficient character with synthetic flexibility. Compared to its amino analog (CAS 40155-43-9), the chloro substituent offers enhanced metabolic stability and distinct reactivity for late-stage functionalization. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to differentially functionalized electron-deficient heterocycles.

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Product Name
5-Chloropyrazine-2-carboxylic acid
CAS Number
36070-80-1
Chinese Name
5-氯吡嗪 -2-羧酸
Synonyms
5-Chloro-2-pyrazinecarboxylic acid; Pyrazine-2-carboxylic acid, 5-chloro-; C₅H₃ClN₂O₂ heterocycle; 5-CPA
Chinese Synonyms
5-氯 -2-吡嗪羧酸; 5-氯吡嗪 -2-甲酸; 氯吡嗪羧酸; 5-位氯 -2-位羧酸吡嗪
Molecular Formula
C₅H₃ClN₂O₂
Molecular Weight
158.54 g/mol
Purity
≥ 98% (HPLC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Halogenated Carboxylic Acids
Appearance
White to Light Yellow to Light Tan Crystalline Powder
Melting Point
 206-210°C (decomposition, literature reference recommended)
pKa
~2.0-3.0 (carboxylic acid, estimated)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong bases to avoid premature chloride displacement or decarboxylation.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, heterocyclic library construction (pyrazino-fused systems), agrochemical intermediate synthesis, amide coupling for drug conjugates, ligand synthesis for coordination chemistry, sequential functionalization via orthogonal Cl/COOH reactivity
Reactivity
Suitable for nucleophilic aromatic substitution (C5-Cl displacement), carboxylic acid activation (EDC/HATU), esterification, heterocyclic fusion, electrophilic aromatic substitution at C3/C6, and Pd-catalyzed cross-coupling
Special Note
✅ Bifunctional Chloroacid Scaffold—C2-COOH for coupling, C5-Cl for substitution/cross-coupling. Electron-deficient pyrazine core provides unique binding geometry vs. phenyl analogs. Distinct from amino analog (CAS 40155-43-9) by metabolic stability. Part of our pyrazine building block series.

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]]> https://wealsunbio.com/product/5-chloro-pyrazine-2-carboxylic-acid/feed/ 0 Ethyl 5-amino-2-pyrazinecarboxylate https://wealsunbio.com/product/ethyl-5-amino-2-pyrazinecarboxylate/ https://wealsunbio.com/product/ethyl-5-amino-2-pyrazinecarboxylate/#respond Sat, 24 Jan 2026 12:13:51 +0000 https://wealsunbio.com/?post_type=product&p=22231 Ethyl 5-amino-2-pyrazinecarboxylate (CAS 54013-06-8) is a strategically bifunctional pyrazine ester engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and antifolate drug development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with an amino substituent at the C5 position and an ethyl ester group at the C2 position. Compared to its methyl ester analog (CAS 13924-94-2), the ethyl ester moiety offers slightly enhanced lipophilicity and potentially altered hydrolysis kinetics, providing flexibility in prodrug design and formulation optimization. The C2-ester serves as a versatile handle for hydrolysis to the free acid, transesterification, or direct amidation, while the C5-amino group provides orthogonal reactivity for acylation, alkylation, diazotization, or heterocyclic fusion. This dual-functionality architecture is particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, antimetabolite analogs (e.g., methotrexate derivatives), and ligands where the aminoester-pyrazine motif balances synthetic flexibility with tunable physicochemical properties. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to functionalized diazine architectures with orthogonal derivatization pathways.

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Product Name
Ethyl 5-amino-2-pyrazinecarboxylate
CAS Number
54013-06-8
Chinese Name
5-氨基吡嗪 -2-羧酸乙酯
Synonyms
Ethyl 5-amino-2-pyrazinecarboxylate; Pyrazine-2-carboxylic acid, 5-amino-, ethyl ester; C₇H₉N₃O₂ heterocycle; Ethyl 5-APCA
Chinese Synonyms
5-氨基 -2-吡嗪羧酸乙酯; 5-氨基吡嗪 -2-甲酸乙酯; 氨基吡嗪羧酸乙酯; 5-位氨基 -2-位乙酯吡嗪
Molecular Formula
C₇H₉N₃O₂
Molecular Weight
167.17 g/mol
Purity
≥ 98% (HPLC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Amino Ester Heterocycles
Appearance
White to Light Yellow to Light Tan Solid
Melting Point
~174-175°C (literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong bases to avoid ester hydrolysis and from strong oxidizing agents to avoid amino group oxidation.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antifolate drug development (methotrexate analogs), heterocyclic library construction (pyrazino-fused systems), prodrug design via ester hydrolysis, amide coupling for drug conjugates, ligand synthesis for coordination chemistry
Reactivity
Suitable for amino group acylation/alkylation, ester hydrolysis to acid, transesterification, heterocyclic fusion, electrophilic aromatic substitution at C3/C6, and salt formation (after hydrolysis)
Special Note
✅ Bifunctional Amino Ester Scaffold—C2-COOEt for hydrolysis/coupling, C5-NH₂ for derivatization. Enhanced lipophilicity vs. methyl ester (CAS 13924-94-2). Part of our pyrazine building block series.

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]]> https://wealsunbio.com/product/ethyl-5-amino-2-pyrazinecarboxylate/feed/ 0 Methyl 5-aminopyrazine-2-carboxylate https://wealsunbio.com/product/methyl-5-aminopyrazine-2-carboxylate/ https://wealsunbio.com/product/methyl-5-aminopyrazine-2-carboxylate/#respond Sat, 24 Jan 2026 12:13:20 +0000 https://wealsunbio.com/?post_type=product&p=22230 Methyl 5-aminopyrazine-2-carboxylate (CAS 13924-94-2) is a strategically bifunctional pyrazine ester engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and antifolate drug development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with an amino substituent at the C5 position and a methyl ester group at the C2 position. The C2-ester moiety serves as a versatile handle for hydrolysis to the free acid, transesterification, or direct amidation, while the C5-amino group provides orthogonal reactivity for acylation, alkylation, diazotization, or heterocyclic fusion. Compared to its carboxylic acid analog (CAS 40155-43-9), the methyl ester form offers enhanced lipophilicity, improved membrane permeability for cellular assays, and simplified purification protocols. This dual-functionality architecture is particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, antimetabolite analogs (e.g., methotrexate derivatives), and prodrug architectures where the aminoester-pyrazine motif balances synthetic flexibility with tunable physicochemical properties. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to functionalized diazine architectures with orthogonal derivatization pathways.

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Product Name
Methyl 5-aminopyrazine-2-carboxylate
CAS Number
13924-94-2
Chinese Name
5-氨基吡嗪 -2-羧酸甲酯
Synonyms
Methyl 5-amino-2-pyrazinecarboxylate; Pyrazine-2-carboxylic acid, 5-amino-, methyl ester; C₆H₇N₃O₂ heterocycle; Methyl 5-APCA
Chinese Synonyms
5-氨基 -2-吡嗪羧酸甲酯; 5-氨基吡嗪 -2-甲酸甲酯; 氨基吡嗪羧酸甲酯; 5-位氨基 -2-位甲酯吡嗪
Molecular Formula
C₆H₇N₃O₂
Molecular Weight
153.15 g/mol
Purity
≥ 98% (HPLC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Amino Ester Heterocycles
Appearance
Light tan to orange solid
Melting Point
~165-170°C (literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong bases to avoid ester hydrolysis and from strong oxidizing agents to avoid amino group oxidation.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antifolate drug development (methotrexate analogs), heterocyclic library construction (pyrazino-fused systems), prodrug design via ester hydrolysis, amide coupling for drug conjugates, ligand synthesis for coordination chemistry
Reactivity
Suitable for amino group acylation/alkylation, ester hydrolysis to acid, transesterification, heterocyclic fusion, electrophilic aromatic substitution at C3/C6, and salt formation (after hydrolysis)
Special Note
✅ Bifunctional Amino Ester Scaffold—C2-COOMe for hydrolysis/coupling, C5-NH₂ for derivatization. Enhanced lipophilicity vs. free acid analog (CAS 40155-43-9). Part of our pyrazine building block series.

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]]> https://wealsunbio.com/product/methyl-5-aminopyrazine-2-carboxylate/feed/ 0 5-AMINO-PYRAZINE-2-CARBOXYLIC ACID https://wealsunbio.com/product/5-amino-pyrazine-2-carboxylic-acid/ https://wealsunbio.com/product/5-amino-pyrazine-2-carboxylic-acid/#respond Sat, 24 Jan 2026 12:12:45 +0000 https://wealsunbio.com/?post_type=product&p=22229 5-Aminopyrazine-2-carboxylic acid (CAS 40155-43-9) is a strategically bifunctional pyrazine scaffold engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and antifolate drug development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with an amino substituent at the C5 position and a carboxylic acid group at the C2 position. The C2-carboxylic acid moiety serves as a versatile handle for amide coupling, esterification, or salt formation, while the C5-amino group provides orthogonal reactivity for acylation, alkylation, diazotization, or heterocyclic fusion. This dual-functionality architecture is particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and antimetabolite analogs (e.g., methotrexate derivatives) where the aminoacid-pyrazine motif optimizes target engagement through specific hydrogen-bonding patterns and ionic interactions. Compared to halogenated pyrazines, this compound offers direct access to amide/peptide-like structures without requiring cross-coupling steps. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to functionalized diazine architectures with tunable solubility and reactivity.

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Product Name
5-Aminopyrazine-2-carboxylic acid
CAS Number
40155-43-9
Chinese Name
5-氨基吡嗪 -2-羧酸
Synonyms
5-Amino-2-pyrazinecarboxylic acid; Pyrazine-2-carboxylic acid, 5-amino-; C₅H₅N₃O₂ heterocycle; 5-APCA
Chinese Synonyms
5-氨基 -2-吡嗪羧酸; 5-氨基吡嗪 -2-甲酸; 氨基吡嗪羧酸; 5-位氨基 -2-位羧酸吡嗪
Molecular Formula
C₅H₅N₃O₂
Molecular Weight
139.11 g/mol
Purity
≥ 98% (HPLC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Amino Acid Heterocycles
Appearance
Light brown to off-white solid
Melting Point
>250°C (decomposition, literature reference recommended)
pKa
~2.5 (COOH), ~5.5 (NH₃⁺, estimated; zwitterionic potential)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong oxidizing agents to avoid amino group oxidation.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antifolate drug development (methotrexate analogs), heterocyclic library construction (pyrazino-fused systems), amide coupling for drug conjugates, ligand synthesis for coordination chemistry, diazotization reactions
Reactivity
Suitable for amino group acylation/alkylation, carboxylic acid activation (EDC/HATU), esterification, heterocyclic fusion, electrophilic aromatic substitution at C3/C6, and salt formation
Special Note
✅ Bifunctional Amino Acid Scaffold—C2-COOH for coupling, C5-NH₂ for derivatization. Electron-deficient pyrazine core provides unique binding geometry vs. phenylalanine analogs. Part of our pyrazine building block series.

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]]> https://wealsunbio.com/product/5-amino-pyrazine-2-carboxylic-acid/feed/ 0 2-Chloro-5-iodopyrazine https://wealsunbio.com/product/2-chloro-5-iodopyrazine/ https://wealsunbio.com/product/2-chloro-5-iodopyrazine/#respond Sat, 24 Jan 2026 12:12:05 +0000 https://wealsunbio.com/?post_type=product&p=22228 2-Chloro-5-iodopyrazine (CAS 1057216-55-3) is a strategically bifunctional halogenated pyrazine scaffold engineered for highly chemoselective cross-coupling reactions, pharmaceutical intermediate synthesis, and materials science development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with a chlorine substituent at the C2 position and an iodine atom at the C5 position. The dual halogen architecture with significantly differentiated reactivity (I >> Cl) enables precise sequential functionalization, allowing researchers to introduce distinct substituents at each position through controlled Pd-catalyzed cross-coupling. The iodine handle offers rapid oxidative addition kinetics, while the chlorine site remains inert under mild conditions, providing superior orthogonality compared to bromo/iodo analogs. The 2,5-substitution pattern creates a symmetric geometry across the ring center, making this intermediate particularly valuable for constructing asymmetric ligands, fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and conjugated materials where stepwise derivatization with high selectivity is critical. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to differentially halogenated electron-deficient heterocycles with enhanced control over reaction sequences.

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Product Name
2-Chloro-5-iodopyrazine
CAS Number
1057216-55-3
Chinese Name
2-氯 -5-碘吡嗪
Synonyms
5-Iodo-2-chloropyrazine; Pyrazine, 2-chloro-5-iodo-; Cl-I-Pyrazine
Chinese Synonyms
5-碘 -2-氯吡嗪; 2-氯 -5-碘代吡嗪; 氯碘吡嗪; 2,5-位卤代吡嗪
Molecular Formula
C₄H₂ClIN₂
Molecular Weight
240.43 g/mol 
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Mixed Dihalo heterocycles
Appearance
White to Off-white to Light Yellow Crystalline Powder
Melting Point
~106-110°C (estimated, literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed in amber glass under inert atmosphere (nitrogen). Protect from light to avoid iodine degradation and from strong bases to avoid premature halide displacement.
Shelf Life
18-24 months under recommended storage conditions (monitor for color darkening due to iodine)
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements (amber glass recommended)
Applications
Kinase inhibitor synthesis, highly chemoselective sequential cross-coupling (I reacts first, Cl remains), asymmetric ligand construction, heterocyclic library construction (pyrazino-fused systems), conjugated material precursor, agrochemical intermediate
Reactivity
Suitable for selective Pd-catalyzed cross-coupling (I reacts much faster than Cl), nucleophilic aromatic substitution (at C2-Cl under harsher conditions), lithiation, electrophilic aromatic substitution at C3/C6, and stepwise derivatization
Special Note
✅ Highly Chemoselective Dihalo Scaffold—Iodine (C5) reacts significantly faster than Chlorine (C2), enabling superior sequential functionalization control vs. Br/I analogs. Light-Sensitive—iodine substituent requires amber storage. Distinct from symmetric dihalides. Part of our halogenated pyrazine series.

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]]> https://wealsunbio.com/product/2-chloro-5-iodopyrazine/feed/ 0 2-Bromo-5-iodopyrazine https://wealsunbio.com/product/2-bromo-5-iodopyrazine/ https://wealsunbio.com/product/2-bromo-5-iodopyrazine/#respond Sat, 24 Jan 2026 12:11:12 +0000 https://wealsunbio.com/?post_type=product&p=22227 2-Bromo-5-iodopyrazine (CAS 622392-04-5) is a strategically bifunctional halogenated pyrazine scaffold engineered for sequential cross-coupling reactions, pharmaceutical intermediate synthesis, and materials science development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with a bromine substituent at the C2 position and an iodine atom at the C5 position. The dual halogen architecture with differentiated reactivity (I > Br) enables chemoselective functionalization, allowing researchers to introduce distinct substituents at each position through controlled Pd-catalyzed cross-coupling (Suzuki, Stille, Negishi, Sonogashira). The 2,5-substitution pattern creates a symmetric geometry across the ring center, while the iodine handle offers faster oxidative addition kinetics compared to the bromine site. This intermediate is particularly valuable for constructing asymmetric ligands, fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and conjugated materials where stepwise derivatization is critical. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to differentially halogenated electron-deficient heterocycles.

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Product Name
2-Bromo-5-iodopyrazine
CAS Number
622392-04-5
Chinese Name
2-溴 -5-碘吡嗪
Synonyms
5-Iodo-2-bromopyrazine; Pyrazine, 2-bromo-5-iodo-; C₄H₂BrIN₂ heterocycle; Br-I-Pyrazine
Chinese Synonyms
5-碘 -2-溴吡嗪; 2-溴 -5-碘代吡嗪; 溴碘吡嗪; 2,5-位卤代吡嗪
Molecular Formula
C₄H₂BrIN₂
Molecular Weight
284.88 g/mol
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Mixed Dihalo heterocycles
Appearance
White to Off-white to Light Yellow Crystalline Powder
Melting Point
~86-90°C (estimated, literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed in amber glass under inert atmosphere (nitrogen). Protect from light to avoid iodine degradation and from strong bases to avoid premature halide displacement.
Shelf Life
18-24 months under recommended storage conditions (monitor for color darkening due to iodine)
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements (amber glass recommended)
Applications
Kinase inhibitor synthesis, sequential cross-coupling reactions (chemoselective functionalization), asymmetric ligand construction, heterocyclic library construction (pyrazino-fused systems), conjugated material precursor, agrochemical intermediate
Reactivity
Suitable for selective Pd-catalyzed cross-coupling (I reacts faster than Br), nucleophilic aromatic substitution, lithiation, electrophilic aromatic substitution at C3/C6, and stepwise derivatization
Special Note
✅ Chemoselective Dihalo Scaffold—Iodine (C5) reacts faster than Bromine (C2), enabling sequential functionalization. Light-Sensitive—iodine substituent requires amber storage. Distinct from symmetric dihalides (e.g., 2,5-dichloro). Part of our halogenated pyrazine series.

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]]> https://wealsunbio.com/product/2-bromo-5-iodopyrazine/feed/ 0 Methyl 2-pyrazinecarboxylate https://wealsunbio.com/product/methyl-2-pyrazinecarboxylate-2/ https://wealsunbio.com/product/methyl-2-pyrazinecarboxylate-2/#respond Sat, 24 Jan 2026 12:07:58 +0000 https://wealsunbio.com/?post_type=product&p=22226 Methyl 2-pyrazinecarboxylate (CAS 6164-79-0) is a strategically functionalized pyrazine ester engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and ligand development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with a methyl ester substituent at the C2 position. The ester moiety serves as a versatile synthetic handle for hydrolysis to the free acid, amide coupling, transesterification, or reduction to the alcohol, while the pyrazine ring provides unique hydrogen-bonding acceptor capability and metabolic stability compared to pyridine analogs. The C2-substitution pattern enables specific binding orientations in kinase active sites and facilitates ortho-directed functionalization strategies. This intermediate is particularly valuable for constructing fused heterocycles (pyrazino-fused systems), ATP-mimetic scaffolds, nitrogen-rich ligands, and prodrug architectures where the pyrazine-ester motif balances electron-deficient character with synthetic flexibility. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to functionalized diazine architectures with tunable reactivity.

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Product Name
Methyl 2-pyrazinecarboxylate
CAS Number
6164-79-0
Chinese Name
吡嗪 -2-羧酸甲酯
Synonyms
Methyl pyrazine-2-carboxylate; 2-(Methoxycarbonyl)pyrazine; Pyrazine-2-carboxylic acid methyl ester; C₆H₆N₂O₂ heterocycle
Chinese Synonyms
2-吡嗪羧酸甲酯; 吡嗪-2-甲酸甲酯; 甲氧羰基吡嗪; 2-位酯基吡嗪
Molecular Formula
C₆H₆N₂O₂
Molecular Weight
138.13 g/mol 
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Heterocyclic Esters
Appearance
Colorless clear liquid
Melting Point
~45-50°C (literature reference recommended)
Boiling Point
~220-230°C at 760 mmHg (estimated)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong bases to avoid ester hydrolysis and from strong acids to avoid pyrazine ring protonation/degradation.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, heterocyclic library construction (pyrazino-fused systems), ligand development for coordination chemistry, prodrug design via ester hydrolysis, amide coupling for drug conjugates, pyrazine-based material precursor
Reactivity
Suitable for ester hydrolysis to acid, amide coupling (activation via EDC/HATU), transesterification, reduction to alcohol, electrophilic aromatic substitution at C3/C5/C6, and Pd-catalyzed cross-coupling (after halogenation)
Special Note
✅ Electron-Deficient Heterocyclic Ester—pyrazine core provides unique binding geometry vs. pyridine analogs. C2-ester enables versatile derivatization via hydrolysis/coupling. Part of our pyrazine building block series.

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]]> https://wealsunbio.com/product/methyl-2-pyrazinecarboxylate-2/feed/ 0 2,5-Dichloropyrazine https://wealsunbio.com/product/25-dichloropyrazine/ https://wealsunbio.com/product/25-dichloropyrazine/#respond Sat, 20 Dec 2025 08:00:33 +0000 https://wealsunbio.com/?post_type=product&p=21937 2,5-Dichloropyrazine (CAS 19745-07-4) is a strategically symmetric dihalogenated pyrazine scaffold engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and agrochemical development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with two chlorine substituents at the C2 and C5 positions. The 2,5-substitution pattern creates a symmetric architecture across the ring center, enabling sequential or simultaneous nucleophilic aromatic substitution (SNAr) or Pd-catalyzed cross-coupling (Suzuki, Buchwald-Hartwig, Stille) at both positions. Compared to vicinal (2,3-) or adjacent (2,6-) dichloropyrazines, the 2,5-isomer offers distinct electronic distribution and steric environments, making it particularly valuable for constructing symmetric ligands, fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and nitrogen-rich materials. The dual chloro handles provide orthogonal reactivity potential when differentiated through controlled substitution, supporting modular synthetic strategies. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to symmetrically functionalized electron-deficient heterocycles.

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Product Name
2,5-Dichloropyrazine
CAS Number
19745-07-4
Chinese Name
2,5-二氯吡嗪
Synonyms
Pyrazine, 2,5-dichloro-; 2,5-Dichloropyrazine; C₄H₂Cl₂N₂ heterocycle; DCP
Chinese Synonyms
2,5-二氯吡嗪; 2,5-位二氯吡嗪; 对称二氯吡嗪
Molecular Formula
C₄H₂Cl₂N₂
Molecular Weight
148.98 g/mol
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Dihalo heterocycles
Appearance
Colorless liquid
Melting Point
~52-54°C (literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong bases to avoid premature chloride displacement and from strong oxidizing agents.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antiviral drug development, agrochemical intermediate synthesis, symmetric ligand construction, heterocyclic library construction (pyrazino-fused systems), sequential functionalization via controlled SNAr
Reactivity
Suitable for nucleophilic aromatic substitution (C2/C5-Cl displacement), Pd-catalyzed cross-coupling (Suzuki, Buchwald-Hartwig), lithiation, electrophilic aromatic substitution at C3/C6, and symmetric/asymmetric derivatization
Special Note
✅ Symmetric Dihalo Scaffold—2,5-substitution offers unique electronic distribution vs. 2,3-/2,6-isomers. Dual activated sites for sequential functionalization. Part of our halogenated pyrazine series.

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]]> https://wealsunbio.com/product/25-dichloropyrazine/feed/ 0 2-Amino-3-chloropyrazine https://wealsunbio.com/product/2-amino-3-chloropyrazine/ https://wealsunbio.com/product/2-amino-3-chloropyrazine/#respond Sat, 20 Dec 2025 07:59:56 +0000 https://wealsunbio.com/?post_type=product&p=21936 2-Amino-3-chloropyrazine (CAS 6863-73-6) is a strategically bifunctional pyrazine scaffold engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and agrochemical development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with an amino substituent at the C2 position and a chlorine atom at the C3 position. The adjacent 2,3-substitution pattern creates unique electronic and steric properties compared to the 2,6-isomer (CAS 33332-28-4), enabling distinct reactivity profiles for sequential functionalization. The C3-chloro handle is activated by the adjacent ring nitrogen and amino group, enabling efficient nucleophilic aromatic substitution (SNAr) or Pd-catalyzed cross-coupling, while the C2-amino group provides orthogonal reactivity for acylation, alkylation, diazotization, or heterocyclic fusion. This dual-functionality architecture is particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and nitrogen-rich ligands where the ortho-chloroamino-pyrazine motif enables unique cyclization pathways and binding geometries. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to differentially functionalized electron-deficient heterocycles with vicinal substitution patterns.

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Product Name
2-Amino-3-chloropyrazine
CAS Number
6863-73-6
Chinese Name
2-氨基 -3-氯吡嗪
Synonyms
3-Chloro-2-aminopyrazine; 3-Chloropyrazin-2-amine; Pyrazine, 3-chloro-2-amino-; C₄H₄ClN₃ heterocycle
Chinese Synonyms
3-氯 -2-氨基吡嗪; 3-氯吡嗪 -2-胺; 氯氨基吡嗪 (2,3-位); 邻氯氨基吡嗪
Molecular Formula
C₄H₄ClN₃
Molecular Weight
129.55 g/mol
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Halogenated Aminoheterocycles
Appearance
White to pale yellow to dark green crystalline powder
Melting Point
~ 152-156°C (decomposition, literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong oxidizing agents to avoid amino group oxidation and from strong bases to avoid premature chloride displacement.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antiviral drug development, agrochemical intermediate synthesis, heterocyclic library construction (pyrazino-fused systems via ortho-cyclization), sequential functionalization via orthogonal Cl/NH₂ reactivity, ligand synthesis for coordination chemistry
Reactivity
Suitable for nucleophilic aromatic substitution (C3-Cl displacement), amino group acylation/alkylation, diazotization, heterocyclic fusion (e.g., pyrazino[2,3-d]pyrimidine via ortho-cyclization), electrophilic aromatic substitution at C5/C6, and Pd-catalyzed cross-coupling
Special Note
✅ Ortho-Bifunctional Scaffold—2,3-adjacent Cl/NH₂ enables unique cyclization pathways vs. 2,6-isomer (CAS 33332-28-4). Electron-deficient pyrazine core provides unique binding geometry. Part of our halogenated aminopyrazine series.

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]]> https://wealsunbio.com/product/2-amino-3-chloropyrazine/feed/ 0 2-Chloro-6-aminopyrazine https://wealsunbio.com/product/2-chloro-6-aminopyrazine/ https://wealsunbio.com/product/2-chloro-6-aminopyrazine/#respond Sat, 20 Dec 2025 07:58:59 +0000 https://wealsunbio.com/?post_type=product&p=21935 2-Chloro-6-aminopyrazine (CAS 33332-28-4) is a strategically bifunctional pyrazine scaffold engineered for heterocyclic diversification, pharmaceutical intermediate synthesis, and agrochemical development. This molecule integrates an electron-deficient pyrazine core—a six-membered aromatic diazine ring with nitrogen atoms at para positions (1,4)—with a chlorine substituent at the C2 position and an amino group at the C6 position. The C2-chloro handle is activated by the adjacent ring nitrogen, enabling efficient nucleophilic aromatic substitution (SNAr) or Pd-catalyzed cross-coupling (Suzuki, Buchwald-Hartwig), while the C6-amino group provides orthogonal reactivity for acylation, alkylation, diazotization, or heterocyclic fusion. This dual-functionality architecture enables sequential or selective functionalization, making it particularly valuable for constructing fused heterocycles (pyrazino-fused systems), kinase inhibitor cores, and nitrogen-rich ligands where the chloroamino-pyrazine motif optimizes target engagement through specific hydrogen-bonding patterns and electronic tuning. Manufactured with purity ≥98% under controlled conditions, it supports drug discovery programs requiring modular access to differentially functionalized electron-deficient heterocycles.

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Product Name
2-Chloro-6-aminopyrazine
CAS Number
33332-28-4
Chinese Name
2-氯 -6-氨基吡嗪
Synonyms
6-Amino-2-chloropyrazine; 2-Chloropyrazin-6-amine; Pyrazine, 2-chloro-6-amino-; C₄H₄ClN₃ heterocycle
Chinese Synonyms
6-氨基-2-氯吡嗪; 2-氯吡嗪-6-胺; 氯氨基吡嗪; 2-氯-6-位氨基吡嗪
Molecular Formula
C₄H₄ClN₃
Molecular Weight
129.55 g/mol
Purity
≥ 98% (HPLC/GC area normalization)
Product Category
Pharmaceutical Intermediates / Pyrazine Derivatives / Halogenated Aminoheterocycles
Appearance
Purple Crystalline Powder
Melting Point
~144 – 147 °C (decomposition, literature reference recommended)
Storage Conditions
Store in a cool, dry, well-ventilated area away from light and moisture. Keep container tightly closed under inert atmosphere (nitrogen). Protect from strong oxidizing agents to avoid amino group oxidation and from strong bases to avoid premature chloride displacement.
Shelf Life
24 months under recommended storage conditions
Packaging
100mg/vial, 500mg/vial, 1g/bottle, 5g/bottle, or customized according to customer requirements
Applications
Kinase inhibitor synthesis, antiviral drug development, agrochemical intermediate synthesis, heterocyclic library construction (pyrazino-fused systems), sequential functionalization via orthogonal Cl/NH₂ reactivity, ligand synthesis for coordination chemistry
Reactivity
Suitable for nucleophilic aromatic substitution (C2-Cl displacement), amino group acylation/alkylation, diazotization, heterocyclic fusion (e.g., triazolo-pyrazine), electrophilic aromatic substitution at C3/C5, and Pd-catalyzed cross-coupling
Special Note
✅ Orthogonal Bifunctional Scaffold—C2-Cl for coupling/SNAr, C6-NH₂ for nucleophilic derivatization. Electron-deficient pyrazine core provides unique binding geometry vs. pyridine analogs. Part of our halogenated aminopyrazine series.

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