Chemical Identity and Physical Properties

4,5-Dichloropyridin-2-amine (SKU D175321) is a pyridine derivative bearing a primary amino group at the 2-position and chlorine atoms at the 4- and 5-positions of the aromatic ring. Its molecular formula is C₅H₄Cl₂N₂ with a calculated molecular weight of approximately 163.00 g/mol.

The compound belongs to the class of halogenated aminopyridines. The electron-withdrawing effect of the ring nitrogen combined with the two chloro substituents renders the aromatic system strongly electron-deficient, making positions 4 and 5 susceptible to nucleophilic aromatic substitution (SNAr). Conversely, the 2-amino group is a moderate electron donor that can participate in hydrogen bonding interactions, influencing both solubility and biological binding affinity.

Typical physical characteristics of related dichloropyridinamine compounds include a solid appearance at room temperature (often white to off-white crystalline powder), moderate melting point, and limited solubility in water but reasonable solubility in polar organic solvents such as DMSO, DMF, and ethanol. Researchers should consult the certificate of analysis (CoA) supplied with SKU D175321 for lot-specific purity, melting point, and spectral data.

Synthetic Applications and Reactivity

The dual electrophilic reactivity of 4,5-dichloropyridin-2-amine makes it a highly versatile intermediate in synthetic and medicinal chemistry. The two C–Cl bonds differ subtly in their electronic environment: the 4-position chlorine, flanked by both the ring nitrogen and the adjacent 5-chloro group, is typically more activated toward SNAr reactions with oxygen, nitrogen, or sulfur nucleophiles.

Palladium-catalysed cross-coupling: Both chloro positions can be engaged in Suzuki–Miyaura, Buchwald–Hartwig, or Negishi coupling reactions under appropriate catalytic conditions, enabling selective mono- or di-functionalisation. Careful selection of ligand and temperature allows sequential coupling when differentiation of the two chlorine sites is required.

Nucleophilic aromatic substitution: Treatment with amines, alkoxides, or thiolates can displace one or both chlorines, providing access to diversely substituted aminopyridine analogues without the need for metal catalysis.

Pharmacophore construction: The 2-amino group serves as a handle for acylation, sulfonylation, or cyclisation reactions, enabling construction of fused heterocycles such as pyrido[2,3-d]pyrimidines and related kinase-inhibitor scaffolds. This compound class has been explored in the discovery of inhibitors targeting various protein kinases, making D175321 relevant to oncology and inflammatory disease research programs.

Researchers are advised to optimise reaction conditions on small scale before scale-up, and to consult primary literature for specific protocols.

Safe Handling, Storage, and Disposal

General precautions: As with all halogenated aromatic amines, 4,5-dichloropyridin-2-amine should be handled with appropriate personal protective equipment (PPE), including nitrile gloves, safety spectacles, and a laboratory coat. Operations that generate dust or aerosols should be performed in a fume hood.

Storage: Store in a tightly sealed container in a cool, dry, well-ventilated area away from incompatible materials such as strong oxidisers and strong acids. Many halogenated aminopyridines are stable at room temperature when kept dry; however, researchers should verify recommended storage temperature on the product label or SDS for SKU D175321.

Stability: The compound is expected to be stable under normal laboratory storage conditions. Prolonged exposure to moisture or light may affect purity over time. Re-analysis by TLC, HPLC, or NMR is recommended if material has been stored for extended periods.

Waste disposal: Dispose of waste containing this compound in accordance with local, national, and institutional regulations governing halogenated organic waste. Do not pour down drains. Consult the Safety Data Sheet (SDS) for SKU D175321 for detailed hazard classification and emergency procedures.

Quality Specifications and Analytical Verification

Aladdin Scientific supplies 4,5-dichloropyridin-2-amine (SKU D175321) with a certificate of analysis (CoA) confirming identity and purity for each lot. Researchers should request and retain the CoA for GLP/GMP documentation purposes.

Identity confirmation: Structural identity is typically verified by one or more of the following techniques: proton and carbon-13 NMR spectroscopy (characteristic aromatic and NH₂ signals), high-resolution mass spectrometry (HRMS) confirming the molecular ion, and infrared spectroscopy (N–H stretches, C–Cl and C=N stretches).

Purity assessment: HPLC (typically reverse-phase C18 column with UV detection at 254 nm or 214 nm) is the standard method for quantifying purity. Residual solvent content may be assessed by ¹H NMR or GC headspace analysis in accordance with ICH Q3C guidelines where relevant.

Appearance: Expected as a solid, typically white to off-white powder or crystals. Any significant discolouration may indicate degradation and warrants re-testing before use.

If lot-specific data are required beyond those provided in the standard CoA, contact Aladdin Scientific technical support for additional characterisation options.