Chemical Structure and Key Properties

5,6-Dichloro-2-methylpyridazin-3(2H)-one belongs to the pyridazinone family of six-membered nitrogen-containing heterocycles. Its structure features a pyridazin-3(2H)-one ring in which the nitrogen at position 2 carries a methyl substituent (lactam N-methyl group), while positions 5 and 6 bear chlorine atoms. The presence of two electrophilic chlorine atoms on the electron-deficient aromatic ring renders the molecule highly amenable to nucleophilic aromatic substitution (SNAr) and transition-metal-catalysed cross-coupling reactions.

The N-methyl lactam functionality provides metabolic stability compared with the free NH analogue and modulates the electronic density of the ring. The combination of the electron-withdrawing lactam carbonyl and the two chlorine atoms makes C5 and C6 activated positions for selective functionalisation, enabling chemists to introduce diverse nucleophiles in a stepwise or one-pot fashion.

Note: Exact physical constants (melting point, solubility, log P) for this specific compound should be confirmed against the Certificate of Analysis supplied with product SKU D726794 or authoritative databases such as PubChem and Reaxys.

Handling, Storage, and Safety Guidelines

Personal Protective Equipment (PPE): When handling 5,6-Dichloro-2-methylpyridazin-3(2H)-one, wear appropriate chemical-resistant gloves (e.g., nitrile), a laboratory coat, and eye protection. Work in a well-ventilated fume hood to minimise inhalation exposure to dust or vapours.

Storage: Store the compound in a tightly sealed container, away from moisture, heat, and incompatible materials (strong bases, reducing agents). Recommended storage temperature is typically 2–8 °C or at room temperature under inert atmosphere; consult the specific product label and SDS for confirmed conditions for SKU D726794.

Waste Disposal: Dispose of residues and contaminated materials in accordance with local, national, and institutional regulations for halogenated organic waste. Do not discharge to drains or the environment.

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

Research and Synthetic Applications

The pyridazinone scaffold is a privileged heterocyclic motif found in numerous bioactive molecules, including pharmaceutical candidates and crop-protection agents. 5,6-Dichloro-2-methylpyridazin-3(2H)-one serves as a versatile electrophilic building block for the construction of more complex analogues through the following strategies:

• Nucleophilic Aromatic Substitution (SNAr): The electron-deficient C5–Cl and C6–Cl bonds undergo selective displacement by nitrogen, oxygen, and sulfur nucleophiles (amines, alcohols, thiols), enabling mono- or di-substituted pyridazinone library synthesis.
• Palladium-Catalysed Cross-Coupling: Both C–Cl positions can participate in Suzuki–Miyaura, Buchwald–Hartwig, and related reactions to install aryl, heteroaryl, or amino groups.
• Agrochemical Research: Chlorinated pyridazinones have been reported as intermediates in the synthesis of herbicidal and fungicidal compounds. This compound may serve as a precursor in such programmes.
• Medicinal Chemistry: The N-methylpyridazinone core is associated with kinase inhibitor and anti-inflammatory pharmacophores; dichloro analogues are used for SAR exploration.

Disclaimer: Specific published yields, reaction conditions, and biological activity data for this exact compound should be verified in primary literature before use in a research programme.

Quality, Purity, and Ordering Information

Aladdin Scientific supplies 5,6-Dichloro-2-methylpyridazin-3(2H)-one under SKU D726794. Each lot is accompanied by a Certificate of Analysis (CoA) detailing purity (typically assessed by HPLC or GC), appearance, and spectroscopic identity confirmation (¹H NMR, MS).

Recommended pre-use checks:

• Verify the CoA matches the received lot number.
• Inspect the compound for colour changes or clumping that may indicate moisture ingress or decomposition.
• For moisture-sensitive reactions, consider drying the compound over P₂O₅ or using freshly opened material stored under inert gas.

For bulk quantities, custom purity grades, or regulatory documentation (e.g., DMF support), contact Aladdin Scientific customer service. Volume pricing and institutional procurement options are available.