1,7-Dibromoheptane
[CAS# 4549-31-9]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Hydrocarbon halide
• Name: 1,7-Dibromoheptane
• Molecular Formula: C₇H₁₄Br₂
• Molecular Weight: 257.99
• CAS Registry Number: 4549-31-9
• EC Number: 224-910-4
• SMILES: C(CCCBr)CCCBr

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*, 1.51 g/mL (Expl.)
• Melting point: 41.7 °C (Expl.)
• Boiling point: 263.0 °C 760 mmHg (Calc.)^*, 255 °C (Expl.)
• Flash point: 132.8±17.7 °C (Calc.)^*, 113 °C (Expl.)
• Index of refraction: 1.498 (Calc.)^*, 1.503 (Expl.)

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

Safety Data

• Hazard Symbols: GHS06 Danger
• Risk Statements: H300
• Safety Statements: P264-P270-P301+P316-P321-P330-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	2	H300
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

Discovery and Applications

1,7-Dibromoheptane is an organic compound featuring a seven-carbon linear alkyl chain substituted with bromine atoms at both terminal carbons. Its molecular formula is C₇H₁₄Br₂, classifying it as a α,ω-dihaloalkane, specifically a dibromo derivative of heptane. The presence of bromine atoms at both ends imparts high reactivity, making 1,7-dibromoheptane a useful intermediate in organic synthesis and materials chemistry.

The compound is commonly synthesized by the bromination of 1,7-heptanediol, where the terminal hydroxyl groups are converted to bromides using reagents such as phosphorus tribromide (PBr₃) or hydrobromic acid under controlled conditions to ensure selective substitution. Alternatively, dibromination of terminal alkenes followed by chain modification can provide 1,7-dibromoheptane.

1,7-Dibromoheptane’s bifunctional bromide groups make it highly reactive toward nucleophilic substitution reactions, allowing the introduction of various nucleophiles including amines, thiols, azides, and cyanides. This reactivity enables its application as a bifunctional alkylating agent in the synthesis of macrocycles, polymers, and cross-linked materials.

In macrocyclic chemistry, intramolecular nucleophilic substitution reactions involving 1,7-dibromoheptane can produce seven-membered ring compounds. Such macrocycles are important in supramolecular chemistry and pharmaceutical development.

In polymer science, 1,7-dibromoheptane serves as a chain extender or cross-linker. Reactions with bifunctional nucleophiles such as diamines or dithiols result in polyamides, polythioethers, and other polymers with tailored flexibility, hydrophobicity, and thermal properties. The seven-carbon alkyl spacer affects the mechanical and physical characteristics of these polymers.

The compound is also used in materials science for surface functionalization and modification. Its bifunctional nature allows covalent attachment to substrates, influencing surface properties such as adhesion, wettability, and molecular organization. These features are useful in coatings, adhesives, and nanotechnology.

Physically, 1,7-dibromoheptane is typically a colorless to pale yellow liquid or low-melting solid. It exhibits limited water solubility but dissolves well in organic solvents like ethers, alcohols, and chlorinated hydrocarbons. The bromine atoms increase molecular weight, boiling point, and density compared to non-halogenated heptanes.

Handling requires caution due to potential alkylating activity and irritant effects. The compound is sensitive to light and heat, which may induce decomposition or elimination reactions, so it should be stored in a cool, dry, and dark environment.

While 1,7-dibromoheptane is not pharmacologically active itself, its derivatives are used in medicinal chemistry for linker design and molecular scaffolding. Its bifunctional bromide groups facilitate conjugation reactions important in drug delivery and biomaterials.

In summary, 1,7-dibromoheptane is a versatile bifunctional intermediate widely applied in organic synthesis, polymer chemistry, and materials science. Its reactive bromine termini and flexible seven-carbon chain allow diverse chemical transformations and functional applications across various scientific and industrial fields.

References

2024. Effect of methylene lengths of 4-(ω-(methylimidazole)-alkyloxy)-4’-(cyano)-biphenyl on cellulose liquid crystal solution and its phase transition properties. Cellulose, 31(10).
DOI: 10.1007/s10570-024-05993-8

2012. 1-Phenoxyalkyl-4-[(N,N-disubstitutedamino)alkyl]piperazine derivatives as non-imidazole histamine H3-antagonists. Medicinal Chemistry Research, 21(6).
DOI: 10.1007/s00044-012-0090-2

2008. With a Bromoalkane. Science of Synthesis.
URL: https://science-of-synthesis.thieme.com/app/text/?id=SD-043-00466