1,8-Dibromooctane
[CAS# 4549-32-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Halogenated aliphatic hydrocarbon
• Name: 1,8-Dibromooctane
• Synonyms: Octamethylene dibromide
• Molecular Formula: C₈H₁₆Br₂
• Molecular Weight: 272.02
• CAS Registry Number: 4549-32-0
• EC Number: 224-912-5
• SMILES: C(CCCCBr)CCCBr

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*, 1.477 g/mL (Expl.)
• Melting point: 12 - 16 °C (Expl.)
• Boiling point: 271.0 °C 760 mmHg (Calc.)^*, 270 - 272 °C (Expl.)
• Flash point: 154.9±17.7 °C (Calc.)^*, 113 °C (Expl.)
• Solubility: water: insoluble (Expl.)
• Index of refraction: 1.496 (Calc.)^*, 1.498 (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

1,8-Dibromooctane is an organic compound consisting of an eight-carbon linear alkyl chain with bromine atoms attached at both terminal carbons. Its molecular formula is C₈H₁₆Br₂, classifying it as an α,ω-dihaloalkane, specifically a dibromo derivative of octane. The presence of two bromine atoms at opposite ends of the molecule imparts high chemical reactivity, making 1,8-dibromooctane a valuable intermediate in organic synthesis and materials science.

The compound is commonly synthesized through the bromination of 1,8-octanediol, where the terminal hydroxyl groups are converted to bromides using reagents such as phosphorus tribromide (PBr₃) or hydrobromic acid (HBr) under carefully controlled reaction conditions to ensure selective substitution and avoid side reactions. Alternative synthetic approaches include halogenation of terminal alkenes or nucleophilic substitution reactions starting from other functionalized octane derivatives.

1,8-Dibromooctane’s bifunctional bromide groups make it highly reactive toward nucleophilic substitution reactions, enabling the introduction of various nucleophiles including amines, thiols, azides, and cyanides. This bifunctionality allows the molecule to serve as a difunctional alkylating agent in the synthesis of macrocycles, polymers, and cross-linked materials.

In macrocyclic chemistry, intramolecular nucleophilic substitution involving 1,8-dibromooctane can yield eight-membered ring compounds. Such macrocycles have applications in supramolecular chemistry, molecular recognition, and as scaffolds in pharmaceutical research.

In polymer science, 1,8-dibromooctane acts as a chain extender or cross-linker. Reaction with bifunctional nucleophiles such as diamines or dithiols produces polymers like polyamides, polythioethers, and other materials. The eight-carbon spacer contributes flexibility, hydrophobicity, and thermal stability to polymer backbones, influencing their mechanical and physical properties.

The compound is also utilized in materials science for surface functionalization and nanostructure modification. Its bifunctional nature allows covalent attachment to various substrates, modifying surface properties such as adhesion, wettability, and molecular organization. These characteristics are valuable in coatings, adhesives, and nanotechnology applications.

Physically, 1,8-dibromooctane is typically a colorless to pale yellow liquid or low-melting solid. It exhibits limited solubility in water but dissolves readily in organic solvents such as ethers, alcohols, and chlorinated hydrocarbons. The presence of bromine atoms increases molecular weight, boiling point, and density compared to non-halogenated octanes.

Handling requires care due to its potential alkylating activity and irritant properties. It is sensitive to light and heat, which can induce decomposition or elimination reactions, necessitating storage in a cool, dry, and dark environment.

Although 1,8-dibromooctane itself is not pharmacologically active, its derivatives are explored in medicinal chemistry for linker synthesis and molecular scaffold design. Its bifunctional bromide groups facilitate conjugation reactions important in drug delivery and biomaterials.

In summary, 1,8-dibromooctane is a versatile bifunctional intermediate widely used in organic synthesis, polymer chemistry, and materials science. Its reactive bromine termini and flexible alkyl chain enable diverse chemical transformations and functional applications across scientific and industrial domains.

References

2023. The synthesis of bisquaternary ammonium compounds (microreview). Chemistry of Heterocyclic Compounds, 59(12).
DOI: 10.1007/s10593-024-03266-7

2023. Synthesis of covalent organic pillars as molecular nanotubes with precise length, diameter and chirality. Nature Synthesis, 2(3).
DOI: 10.1038/s44160-022-00235-w

2021. Synthesis and crystalline structure of poly(p-phenylene alkylene)s and poly(p-phenylene co-alkylenes)s by Kumada coupling reaction of α,ω-dibromoalkane and p-dichlorobenzene. Journal of Polymer Research, 28(12).
DOI: 10.1007/s10965-021-02849-8