Compound Overview and Chemical Properties

5-Bromo-2-chloro-N-cyclopentylpyrimidin-4-amine (Aladdin SKU B590027) is a difunctionalised pyrimidine derivative carrying two distinct halogen substituents—bromine at the 5-position and chlorine at the 2-position—together with a secondary cyclopentylamine group at the 4-position. This combination of leaving groups provides orthogonal reactivity: the C–Br bond at C-5 is well-suited to palladium-catalysed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig), while the C–Cl bond at C-2 can undergo selective nucleophilic aromatic substitution (SNAr) with amines, thiols, or other nucleophiles under milder conditions. The cyclopentyl group at N-4 imparts lipophilicity and conformational rigidity, features valued in drug-discovery programmes targeting kinases and other enzymatic receptors. The compound is typically a solid at room temperature and should be handled under standard laboratory fume-hood conditions.

Safety and Handling Precautions

Before working with 5-Bromo-2-chloro-N-cyclopentylpyrimidin-4-amine, consult the Safety Data Sheet (SDS) supplied by Aladdin Scientific. The compound contains halogen atoms and an aromatic amine moiety; treat it as a potential irritant to skin, eyes, and the respiratory tract.

• Personal Protective Equipment (PPE): Wear appropriate laboratory gloves (nitrile recommended), safety goggles, and a laboratory coat at all times during handling.
• Ventilation: Work inside a chemical fume hood to minimise inhalation exposure to dust or vapours.
• Skin/Eye Contact: In the event of skin contact, wash immediately with soap and copious water for at least 15 minutes. For eye contact, irrigate with water for at least 15 minutes and seek medical advice.
• Waste Disposal: Dispose of all waste in accordance with local, institutional, and governmental regulations for halogenated organic compounds.

No specific acute toxicity data for this compound were available in the source material; users should treat it with the caution appropriate for a reactive halogenated heterocycle.

Solubility, Reconstitution, and Stock Solution Preparation

5-Bromo-2-chloro-N-cyclopentylpyrimidin-4-amine is expected to show good solubility in common polar aprotic organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), and dichloromethane (DCM), based on its molecular structure. Solubility in water is anticipated to be low due to the hydrophobic cyclopentyl group and the halogenated aromatic core.

Recommended procedure for stock solution preparation:

1. Allow the sealed vial to equilibrate to room temperature before opening to prevent moisture condensation on the solid.
2. Weigh the required amount of compound using a calibrated analytical balance inside a fume hood.
3. Transfer to a clean, dry glass vial and add the appropriate volume of anhydrous DMSO or DMF to achieve the desired concentration (e.g., 10–100 mM for synthetic applications).
4. Vortex or sonicate gently until fully dissolved. Visual inspection should confirm a clear solution.
5. Aliquot into single-use portions to avoid repeated freeze–thaw cycles, which can degrade reagent quality.

Note: Actual solubility data for this specific compound were not provided in the source material. Users should verify solubility experimentally and consult the SDS.

Storage Conditions and Stability

To maintain the integrity of 5-Bromo-2-chloro-N-cyclopentylpyrimidin-4-amine over time, observe the following storage guidelines:

• Temperature: Store in a cool, dry environment. Refrigerated storage (2–8 °C) is generally recommended for halogenated pyrimidine derivatives to slow potential decomposition.
• Moisture protection: Keep the container tightly sealed. Use desiccants (e.g., silica gel) if the compound will be stored for extended periods, as moisture can promote hydrolysis of the C–Cl bond.
• Light protection: Store away from direct light to prevent photodegradation.
• Inert atmosphere: For long-term storage or highly sensitive applications, consider storing under an inert gas (nitrogen or argon) blanket.
• Shelf life: Specific shelf-life data were not provided in the source material; verify the expiry date on the product label and retest purity before use in critical applications.

Typical Synthetic Applications

The orthogonal reactivity of the two C–halogen bonds in 5-Bromo-2-chloro-N-cyclopentylpyrimidin-4-amine makes it a valuable building block in multi-step synthetic sequences, particularly in medicinal chemistry and drug discovery:

• SNAr at C-2 (C–Cl): The chloro group at the electron-deficient 2-position of the pyrimidine ring is susceptible to nucleophilic aromatic substitution. Primary and secondary amines, alkoxides, and thiolates can displace chloride under mild heating conditions, enabling introduction of diverse pharmacophoric groups.
• Palladium-catalysed cross-coupling at C-5 (C–Br): The aryl bromide at C-5 participates efficiently in Suzuki–Miyaura (with arylboronic acids), Negishi, Stille, and Buchwald–Hartwig amination reactions, allowing attachment of aryl, heteroaryl, or amino groups.
• Sequential functionalisation: By exploiting the differential reactivity (C–Cl reacts preferentially in SNAr; C–Br reacts preferentially in Pd-catalysed coupling), chemists can install two different substituents in a controlled, sequential manner to build complex, drug-like pyrimidine scaffolds.
• Kinase inhibitor synthesis: Pyrimidine cores bearing cycloalkylamine groups are recurring motifs in approved kinase inhibitors; this compound serves as a convenient starting material for library synthesis and SAR exploration.

Specific literature references for reactions using this exact compound were not available in the source material and should be verified independently.