Compound Overview and Structural Features

2-Chloro-1H,4H-pyrrolo[2,1-f][1,2,4]triazin-4-one (Aladdin SKU: C174617) belongs to the pyrrolo[2,1-f][1,2,4]triazine family of fused bicyclic nitrogen heterocycles. The scaffold consists of a five-membered pyrrole ring fused to a six-membered 1,2,4-triazin-4-one ring, creating an electron-deficient aromatic system. The lactam carbonyl at position 4 and the chlorine substituent at position 2 define the compound's key physicochemical and reactivity profile.

The electron-withdrawing nature of the triazinone ring activates the C-2 chlorine toward nucleophilic aromatic substitution (SNAr), enabling straightforward displacement by amines, alcohols, thiols, and other nucleophiles under mild conditions. The compound can also participate in transition-metal-catalysed cross-coupling reactions (e.g., Suzuki, Buchwald–Hartwig) at the C-2 position, providing access to a broad library of C-N and C-C bonded analogues.

This scaffold closely mimics the purine ring system found in naturally occurring nucleosides, which underpins its widespread use as a synthetic starting material in medicinal chemistry programmes targeting viral polymerases and protein kinases.

Handling, Safety and Storage

Personal Protective Equipment (PPE): Researchers should wear appropriate PPE when handling this compound, including chemical-resistant gloves (nitrile recommended), a laboratory coat, and safety goggles. For weighing or any operation that may generate dust or aerosol, work inside a fume hood or use a dust mask rated for fine chemical particles.

Storage: Store the compound in a tightly sealed container in a cool (typically 2–8 °C or as specified on the Certificate of Analysis), dry, and well-ventilated area, protected from moisture and light. Prolonged exposure to humidity may promote hydrolysis of the C-Cl bond or ring-opening side reactions. Always check the Certificate of Analysis (CoA) supplied with each lot for lot-specific storage conditions and retest dates.

Waste Disposal: Dispose of waste material in accordance with local, regional, and national regulations governing halogenated organic compounds. Do not dispose of down the drain. Consult your institution's Environmental Health and Safety (EHS) office for approved disposal routes.

First Aid: In case of skin or eye contact, flush immediately with copious water for at least 15 minutes and seek medical advice. If inhaled, move to fresh air. Refer to the Safety Data Sheet (SDS) for full hazard and first-aid information.

Synthetic Applications and Reaction Protocols

Nucleophilic Aromatic Substitution (SNAr): The C-2 chloro group is readily displaced by primary and secondary amines in polar aprotic solvents such as DMF, DMSO, or NMP at temperatures ranging from room temperature to 100 °C, depending on nucleophile reactivity. Typical bases used to neutralise the generated HCl include triethylamine, DIPEA, or K₂CO₃. Reaction progress can be monitored by TLC or HPLC.

Palladium-Catalysed Cross-Coupling: The C-2 chloride is a competent electrophile in Suzuki–Miyaura (with boronic acids/esters), Buchwald–Hartwig (C-N coupling with amines), and related Pd-catalysed reactions. Standard Pd catalysts (e.g., Pd(PPh₃)₄, Pd₂(dba)₃ with suitable ligand) and inorganic bases in aqueous/organic mixed solvents are applicable. Optimisation of catalyst loading, ligand, base, and temperature is recommended for each specific coupling partner.

N-1 Functionalisation: The NH at position 1 can be protected (e.g., as Boc, SEM, or PMB derivatives) prior to C-2 manipulation to avoid competitive N-alkylation or interference in subsequent steps. Selective N-protection should be confirmed by NMR.

Quality Check Before Use: Verify compound identity and purity by ¹H NMR, LC-MS, or HPLC against the CoA before commencing synthesis. This is especially important when the compound has been stored for extended periods or when working with moisture-sensitive downstream steps.

Quality, Purity and Analytical Characterisation

Each lot of 2-chloro-1H,4H-pyrrolo[2,1-f][1,2,4]triazin-4-one (C174617) supplied by Aladdin Scientific is accompanied by a Certificate of Analysis (CoA) documenting lot-specific purity data. Researchers should request and review the CoA prior to use.

Recommended Analytical Methods:

• ¹H and ¹³C NMR: Primary tool for structural confirmation. Key signals include the lactam NH (broad, exchangeable), aromatic/vinyl CH protons of the pyrrole ring, and absence of signals inconsistent with the expected structure.
• LC-MS: Used to confirm molecular weight ([M+H]⁺ or [M-H]⁻ depending on ionisation mode) and assess purity by UV trace at 254 nm or 214 nm. The molecular formula is C₆H₄ClN₃O.
• HPLC: Reverse-phase HPLC (C18 column, acetonitrile/water gradient) provides a quantitative purity assessment. A purity of ≥95% (as measured by peak area normalisation) is typically expected for synthetic-grade material.
• Melting Point: A sharp, reproducible melting point consistent with published values or the CoA supports compound integrity.

If analytical data diverge significantly from the CoA, contact Aladdin Scientific customer support with your lot number for technical assistance.

Ordering, Availability and Technical Support

Ordering: 2-Chloro-1H,4H-pyrrolo[2,1-f][1,2,4]triazin-4-one is available from Aladdin Scientific under catalogue number C174617. Orders can be placed through the Aladdin Scientific website, by email, or through your local authorised distributor. Quantity availability and lead times may vary; contact customer service for bulk or custom quantity enquiries.

Certificate of Analysis and SDS: The CoA and Safety Data Sheet (SDS) for each lot are available on the Aladdin Scientific website by entering the lot number, or by contacting customer support directly. Always use the lot-specific CoA rather than a generic document.

Technical Support: For application-specific questions, custom synthesis enquiries, or analytical data interpretation, contact the Aladdin Scientific technical support team. Provide the catalogue number (C174617), lot number, and a description of your application to receive the most relevant assistance.

Returns and Quality Issues: If the received material does not meet specifications stated in the CoA, Aladdin Scientific's returns and refunds policy applies. Please refer to the website or contact customer service within the applicable notification window.