(6-Chloropyrazin-2-yl)methanamine HCl: Properties & Applications

(6-Chloropyrazin-2-yl)methanamine hydrochloride is a versatile heterocyclic building block featuring both a reactive chloropyrazine ring and a primary amine handle, making it a valuable intermediate in medicinal chemistry and drug discovery programs.

Chemical Name

(6-Chloropyrazin-2-yl)methanamine hydrochloride

SKU / Catalog Number

C190694

Molecular Formula

C5H7ClN3·HCl (free base: C5H7ClN3)

Core Scaffold

Chloropyrazine with aminomethyl substituent

Primary Reactivity

Nucleophilic aromatic substitution at C-6 chloride; acylation, reductive amination, and coupling reactions at the primary amine

Physical Form

Solid salt (hydrochloride)

Storage Recommendation

Store in a cool, dry place; protect from moisture and light

Chemical Structure and Key Functional Groups

(6-Chloropyrazin-2-yl)methanamine hydrochloride (SKU: C190694) consists of a six-membered aromatic pyrazine ring bearing a chlorine substituent at the 6-position and an aminomethyl (–CH₂NH₂) group at the 2-position, supplied as the hydrochloride salt for improved stability and ease of handling. The pyrazine scaffold is a diazine ring containing two nitrogen atoms in a 1,4-arrangement, conferring electron-deficient character that enhances the susceptibility of the C–Cl bond toward nucleophilic aromatic substitution (SNAr). The primary amine tether at C-2 provides an orthogonal handle for further functionalization, enabling dual-site elaboration of the molecule in a single synthetic sequence. Together, these features make the compound a highly versatile bifunctional building block for the construction of complex nitrogen-rich heterocyclic architectures commonly found in pharmaceutically active compounds.

Synthetic Applications and Reactivity

The compound participates in two principal classes of chemical transformation:

• Nucleophilic Aromatic Substitution (SNAr): The electron-withdrawing pyrazine nitrogens activate the C-6 chlorine toward displacement by a range of nucleophiles including primary and secondary amines, alkoxides, and thiolates, enabling rapid access to 6-substituted pyrazin-2-ylmethylamine derivatives under mild conditions.
• Amine-Directed Reactions: The free primary amine (after salt neutralization) undergoes standard transformations such as amide bond formation via coupling with carboxylic acids or acyl chlorides, reductive amination with aldehydes, sulfonylation, and urea or carbamate formation. These reactions allow the introduction of diverse pharmacophoric elements appended to the pyrazine core.

The orthogonality of the two reactive sites enables sequential, chemoselective derivatization strategies, which are particularly valuable in fragment-based drug design and combinatorial library synthesis. The hydrochloride salt form offers superior bench stability relative to the free base, and the amine can be liberated by treatment with a suitable base prior to reaction.

Role in Medicinal Chemistry and Drug Discovery

Pyrazine-containing scaffolds are well-represented in approved pharmaceuticals and drug candidates, valued for their favorable physicochemical properties including improved aqueous solubility relative to carbocyclic analogs, metabolic stability, and the capacity to act as hydrogen-bond acceptors. The aminomethylpyrazine core present in (6-Chloropyrazin-2-yl)methanamine hydrochloride serves as a privileged fragment in kinase inhibitor programs, antibacterial research, and CNS-targeted drug discovery, where pyrazine rings are known to facilitate blood–brain barrier permeation through modulation of lipophilicity and polar surface area.

The bifunctional nature of the building block allows medicinal chemists to rapidly generate structure–activity relationship (SAR) arrays by independently varying substituents at the C-6 position and the nitrogen of the aminomethyl group, providing efficient coverage of chemical space around the pyrazine pharmacophore. As such, C190694 is well-suited for use in automated parallel synthesis platforms and high-throughput medicinal chemistry campaigns.

Handling, Storage, and Safety Considerations

As with all primary amine hydrochloride salts and chloroheterocyclic compounds, appropriate laboratory safety precautions should be observed when working with (6-Chloropyrazin-2-yl)methanamine hydrochloride:

• Personal Protective Equipment (PPE): Wear suitable laboratory gloves, safety glasses or goggles, and a lab coat. Work in a well-ventilated area or fume hood when handling powders to avoid inhalation of dust.
• Storage: Store in a tightly sealed container in a cool, dry environment, protected from moisture, heat, and direct light. The hydrochloride salt form provides enhanced ambient stability relative to the free base.
• Compatibility: Avoid contact with strong oxidizing agents, strong bases (which will liberate the free amine), and reactive acyl halides unless the reaction is intentional.
• Disposal: Dispose of waste in accordance with local institutional and regulatory guidelines for chemical waste.

Researchers should consult the full Safety Data Sheet (SDS) provided by Aladdin Scientific for comprehensive hazard information before use.

Frequently asked questions

What types of reactions is (6-Chloropyrazin-2-yl)methanamine hydrochloride most suitable for?

This compound is particularly well-suited for nucleophilic aromatic substitution (SNAr) at the C-6 chlorine position and for amine-directed reactions—such as amide coupling, reductive amination, and sulfonylation—at the primary amine group. Its bifunctional nature enables sequential, chemoselective elaboration at both sites within a single synthesis.

How should the hydrochloride salt be handled when the free base amine is required for a reaction?

The free base amine can be liberated by treating the hydrochloride salt with a suitable base—commonly an inorganic base such as potassium carbonate or sodium hydroxide in aqueous or mixed solvent systems, or a tertiary amine base such as triethylamine in organic solvents—prior to or during the reaction. The choice of base and solvent should be matched to the subsequent reaction conditions to avoid unwanted side reactions.

What are the recommended storage conditions for C190694?

(6-Chloropyrazin-2-yl)methanamine hydrochloride should be stored in a tightly sealed container in a cool, dry place, away from moisture, direct sunlight, and heat sources. The hydrochloride salt form offers improved stability over the free base under ambient conditions. Always consult the Aladdin Scientific SDS for the most current and product-specific storage guidance.

Is (6-Chloropyrazin-2-yl)methanamine hydrochloride suitable for fragment-based drug discovery?

Yes. The compound's compact molecular size, dual orthogonal reactive handles, and pyrazine core—a privileged scaffold in medicinal chemistry—make it an excellent fragment for FBDD applications. Researchers can rapidly explore SAR around the pyrazine pharmacophore by independently modifying the C-6 chloro substituent and the aminomethyl nitrogen, facilitating efficient chemical space coverage.

References

1. Carey, F. A.; Sundberg, R. J. Advanced Organic Chemistry, Part A: Structure and Mechanisms, 5th ed.; Springer: New York, 2007. (Nucleophilic aromatic substitution reactions of electron-deficient heterocycles.)
2. Meanwell, N. A. Synopsis of Some Recent Tactical Application of Bioisosteres in Drug Design. J. Med. Chem. 2011, 54, 2529–2591. (Discussion of pyrazine scaffolds and their physicochemical properties in drug design.) doi:10.1021/jm1013693
3. Roughley, S. D.; Jordan, A. M. The Medicinal Chemist's Toolbox: An Analysis of Reactions Used in the Pursuit of Drug Candidates. J. Med. Chem. 2011, 54, 3451–3479. (Frequency and utility of SNAr and amide coupling in medicinal chemistry synthesis.) doi:10.1021/jm200187y

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