What Is 7-Bromo-1-heptanol and What Are Its Key Properties?

7-Bromo-1-heptanol (CAS 4286-55-9) is a linear, seven-carbon bifunctional molecule with the molecular formula C₇H₁₅BrO and a molecular weight of approximately 195.10 g/mol. It carries two orthogonally reactive functional groups: a primary alkyl bromide at the omega (C-7) position and a primary hydroxyl group at C-1. This combination makes it one of the most synthetically flexible omega-bromoalcohols available for laboratory use.

The compound is typically supplied as a colorless to pale yellow liquid. Its amphiphilic character—a polar hydroxyl terminus and a reactive carbon–bromine bond—gives it broad solubility in common organic solvents such as dichloromethane, tetrahydrofuran, ethanol, and diethyl ether, while showing limited miscibility with water.

What Are the Main Synthetic Applications of 7-Bromo-1-heptanol?

The dual functionality of 7-Bromo-1-heptanol makes it indispensable in a broad range of synthetic strategies. Key applications include:

• Alkylation reactions: The primary alkyl bromide is an excellent electrophile for O-, N-, S-, and C-alkylation of nucleophiles, including phenols, amines, thiols, malonates, and other active-methylene compounds.
• Etherification and esterification: The hydroxyl group can be converted to ethers via Williamson ether synthesis or to esters using acid chlorides or anhydrides, enabling incorporation into more complex molecular architectures.
• Linker and spacer introduction: The seven-carbon chain serves as a hydrophobic spacer in the synthesis of surfactants, self-assembling monolayers (SAMs), lipid analogs, and prodrug conjugates.
• Further functionalization: Either terminus can be selectively transformed—for example, the hydroxyl can be oxidized to an aldehyde or acid, or converted to a tosylate or mesylate for additional displacement chemistry, while the bromide can participate in metal-catalyzed cross-coupling reactions.
• Polymer and material science: Used as a monomer or end-capper in the preparation of functional polymers and surface-active materials.

How Should 7-Bromo-1-heptanol Be Stored and Handled Safely?

Storage: Store 7-Bromo-1-heptanol in a tightly sealed container away from light, heat, and moisture. A cool, dry environment (typically 2–8 °C or room temperature under inert atmosphere depending on supplier specifications) is recommended to minimize slow auto-oxidation of the hydroxyl group and potential dehydrohalogenation. Keep away from strong bases, oxidizers, and reactive metals.

Personal Protective Equipment (PPE): Wear appropriate chemical-resistant gloves (e.g., nitrile), safety goggles, and a laboratory coat when handling. Work in a well-ventilated fume hood to avoid inhalation of vapors.

First Aid: In case of skin or eye contact, flush immediately with copious amounts of water for at least 15 minutes and seek medical attention if irritation persists. If inhaled, move to fresh air. Consult the Safety Data Sheet (SDS) for complete hazard information before use.

Disposal: Dispose of according to local regulations for halogenated organic waste. Do not pour down the drain.

How Can Selectivity Be Achieved When Reacting Only One Functional Group?

Achieving chemoselectivity in 7-Bromo-1-heptanol is straightforward due to the inherently different reactivity profiles of the two groups:

• Selective reaction at the bromide: Nucleophilic substitution (SN2) proceeds readily at the primary alkyl bromide under mild basic or neutral conditions. The hydroxyl group is far less reactive toward nucleophiles and remains intact under standard SN2 conditions without requiring protection.
• Selective reaction at the hydroxyl: The hydroxyl can be acylated, sulfonylated, or oxidized under conditions that leave the C–Br bond unaffected. For example, treatment with tosyl chloride/pyridine at low temperature selectively tosylates the OH without displacing the bromide.
• Protection strategies: When both groups must be differentiated in multistep synthesis, the hydroxyl can be protected as a silyl ether (e.g., TBS or TMS ether) or a benzyl ether, and deprotected orthogonally after manipulation of the bromide, or vice versa.

Careful choice of reagents, temperature, and solvent polarity allows researchers to exploit each terminus independently in complex synthetic sequences.

Purity, Grade, and Quality Specifications

For research applications, 7-Bromo-1-heptanol is typically offered at purities of ≥95% or higher as determined by GC or titration methods. Researchers should confirm the certificate of analysis (CoA) provided with each lot, which typically includes:

• Purity (GC area %)
• Appearance (color and clarity)
• Identity confirmation (NMR or IR)
• Water content (Karl Fischer, where applicable)

For sensitive applications such as SAM formation, surface chemistry, or asymmetric synthesis, higher-purity grades (≥98%) are advisable to minimize side reactions from halide impurities or diol byproducts. Contact Aladdin Scientific to request specific lot CoAs or custom purity grades.