3-Bromo-1H-1,2,4-triazole: Properties, Handling & Lab Use Guide
3-Bromo-1H-1,2,4-triazole: Properties, Handling & Lab Use Guide
3-Bromo-1H-1,2,4-triazole is a halogenated five-membered nitrogen-containing heterocycle widely employed as a versatile synthetic building block in medicinal chemistry, agrochemical research, and materials science.
- Chemical Name
- 3-Bromo-1H-1,2,4-triazole
- Molecular Formula
- C₂H₂BrN₃
- Molecular Weight
- 147.96 g/mol
- Core Scaffold
- 1,2,4-Triazole (five-membered aromatic heterocycle with three nitrogen atoms)
- Key Functional Feature
- C-3 bromine substituent enabling cross-coupling and nucleophilic substitution reactions
- Aladdin SKU
- B587371
Chemical Identity and Physical Properties
3-Bromo-1H-1,2,4-triazole (CAS number should be verified; see review flags) is a brominated derivative of the parent 1,2,4-triazole heterocycle. Its molecular formula is C₂H₂BrN₃, corresponding to a molecular weight of approximately 147.96 g/mol. The compound features a planar, aromatic five-membered ring containing nitrogen atoms at positions 1, 2, and 4, with a bromine atom at position 3 and an N–H tautomeric proton at position 1.
The 1,2,4-triazole ring system is electron-deficient and aromatic by the Hückel criterion (6 π-electrons), conferring notable thermal and chemical stability. The C-3 carbon bearing the bromine atom is electrophilically activated relative to unsubstituted triazole, making this position highly amenable to metal-catalyzed cross-coupling reactions. The compound is typically a solid at room temperature; researchers should consult the certificate of analysis (CoA) supplied with each lot for confirmed melting point, purity, and appearance.
Synthetic Applications and Reactivity
The bromine substituent at C-3 of 3-Bromo-1H-1,2,4-triazole renders it an exceptionally useful electrophilic partner in a range of modern synthetic transformations:
- Palladium-catalyzed cross-coupling: The C–Br bond participates in Suzuki–Miyaura, Negishi, Stille, and Buchwald–Hartwig coupling reactions, enabling introduction of aryl, heteroaryl, vinyl, or amino groups at position 3 of the triazole ring.
- Nucleophilic substitution: Under appropriate activation conditions, the C-3 position can undergo nucleophilic aromatic substitution (SNAr) with suitable nucleophiles such as amines and alkoxides, facilitating library synthesis.
- N-Alkylation and N-functionalization: The tautomeric N–H can be alkylated selectively under basic conditions, generating N1- or N4-substituted triazole products depending on reaction conditions and protecting group strategy.
- Metal complexation: The triazole nitrogen atoms serve as ligands for transition metals, and 3-substituted derivatives are frequently incorporated into coordination polymers and metal-organic frameworks (MOFs).
These reaction pathways make 3-Bromo-1H-1,2,4-triazole a high-value building block in the preparation of pharmaceutical candidates, particularly antifungal agents, kinase inhibitors, and antimicrobial compounds, where triazole motifs are pharmacophorically privileged.
Storage, Handling, and Safety Guidelines
Storage: Store 3-Bromo-1H-1,2,4-triazole in a tightly sealed container under dry, cool conditions, away from light and moisture. A desiccated environment (e.g., inert atmosphere or desiccant) is recommended for long-term storage to prevent hydrolysis or oxidative degradation of the C–Br bond. Refer to the product-specific Safety Data Sheet (SDS) for confirmed storage temperature recommendations.
Handling precautions: As with most organobromine heterocycles, appropriate personal protective equipment (PPE) must be worn, including chemically resistant gloves, safety goggles, and a laboratory coat. All manipulations should be performed in a well-ventilated fume hood. Avoid inhalation of dust or vapors and contact with skin and eyes.
Waste disposal: Dispose of waste material in accordance with applicable local, national, and institutional regulations governing halogenated organic compounds. Do not discharge into drains or the environment.
First aid: In case of skin or eye contact, rinse immediately with copious amounts of water. Seek medical attention if irritation persists. Consult the SDS for complete hazard and first-aid information specific to this compound.
Quality, Purity, and Procurement Considerations
For research applications, the purity of 3-Bromo-1H-1,2,4-triazole is critical because impurities — particularly regioisomeric triazoles, dehalogenated parent compound, or dibromo byproducts — can negatively affect reaction yields and product selectivity in downstream synthesis steps.
Aladdin Scientific supplies 3-Bromo-1H-1,2,4-triazole under SKU B587371. Each lot is accompanied by a Certificate of Analysis (CoA) confirming identity, purity, and physical characteristics. Researchers are advised to:
- Verify the CoA upon receipt and confirm purity by appropriate analytical techniques (e.g., ¹H NMR, GC, HPLC) before use in critical synthetic steps.
- Request the SDS for full hazard classification, handling, and disposal information.
- Contact Aladdin Scientific technical support for custom pack sizes, bulk quantities, or specific purity grades required for GMP-adjacent research workflows.
Proper characterization of each batch ensures reproducible experimental outcomes and supports robust scientific record-keeping.
Frequently asked questions
What reactions can 3-Bromo-1H-1,2,4-triazole undergo at the C-3 bromine position?
The C-3 bromine makes 3-Bromo-1H-1,2,4-triazole compatible with palladium-catalyzed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig) and, under suitable conditions, nucleophilic aromatic substitution. These transformations allow introduction of diverse functional groups at position 3, greatly expanding accessible chemical space.
How should 3-Bromo-1H-1,2,4-triazole be stored to maintain stability?
The compound should be stored in a tightly sealed container under cool, dry, and dark conditions, ideally with a desiccant or under an inert atmosphere to minimize moisture exposure. Degradation pathways include hydrolysis of the C–Br bond and potential tautomeric instability in the presence of protic solvents; always consult the product SDS for lot-specific recommendations.
Is 3-Bromo-1H-1,2,4-triazole the same compound as 3-bromotriazole, and what distinguishes it from positional isomers?
3-Bromo-1H-1,2,4-triazole is indeed commonly referred to as 3-bromotriazole and belongs to the 1,2,4-triazole family, in which nitrogen atoms occupy positions 1, 2, and 4. This distinguishes it from 1,2,3-triazole-derived bromo analogs, where nitrogen atoms are at positions 1, 2, and 3. The positional arrangement of ring nitrogens governs the compound's electronic properties, tautomeric behavior, and reactivity, making precise specification of regiochemistry essential when ordering or referencing the compound.
What analytical methods are recommended to verify the purity of 3-Bromo-1H-1,2,4-triazole upon receipt?
Proton NMR (¹H NMR) in a deuterated solvent (e.g., DMSO-d₆ or CDCl₃) is the primary method to confirm structure and identify regioisomeric impurities. GC or HPLC with UV detection can quantify purity percentage, while mass spectrometry provides unambiguous molecular weight confirmation. Always cross-reference results with the Aladdin CoA supplied with each lot.
References
- Comprehensive Heterocyclic Chemistry (Elsevier) — Chapter on 1,2,4-Triazoles: general reactivity, tautomerism, and synthetic utility of halogenated triazole derivatives.
- Joule, J. A.; Mills, K. Heterocyclic Chemistry, 5th ed.; Wiley-Blackwell, 2010 — Standard reference for triazole ring chemistry and halogenation reactivity.
- Aladdin Scientific Product Page — 3-Bromo-1H-1,2,4-triazole, SKU B587371, with associated Certificate of Analysis and Safety Data Sheet.
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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