1,6-Dibromohexane
[CAS# 629-03-8]

Identification

• Classification: Chemical reagent >> Organic reagent >> Halogenated aliphatic hydrocarbon
• Name: 1,6-Dibromohexane
• Synonyms: Hexamethylene dibromide
• Molecular Formula: C₆H₁₂Br₂
• Molecular Weight: 243.97
• CAS Registry Number: 629-03-8
• EC Number: 211-067-2
• SMILES: C(CCCBr)CCBr

Properties

• Density: 1.6±0.1 g/cm³ Calc.^*, 1.586 g/mL (Expl.)
• Melting point: -2 - 2.5 ºC (Expl.)
• Boiling point: 244.1±8.0 ºC 760 mmHg (Calc.)^*, 243 ºC (Expl.)
• Flash point: 110.8±17.7 ºC (Calc.)^*, 113 ºC (Expl.)
• Solubility: water insoluble (Expl.)
• Index of refraction: 1.5 (Calc.)^*, 1.507 (Expl.)

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

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS09 Danger
• Hazard Statements: H300-H302-H317-H411
• Precautionary Statements: P261-P264-P270-P272-P273-P280-P301+P316-P301+P317-P302+P352-P321-P330-P333+P317-P362+P364-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin sensitization	Skin Sens.	1	H317
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Skin sensitization	Skin Sens.	1B	H317
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335

• Transport Information: UN 2810

Discovory and Applicatios

1,6-Dibromohexane is a linear aliphatic dibromoalkane with the molecular formula C₆H₁₂Br₂. It consists of a six-carbon chain with bromine atoms attached at both terminal positions, making it a symmetrical dihalide. This compound appears as a colorless to pale yellow liquid and is primarily employed as an intermediate in organic synthesis due to its bifunctional reactivity, which allows for the formation of a variety of chemical structures through substitution or elimination reactions.

The synthesis of 1,6-dibromohexane is generally achieved by the bromination of hexane derivatives. One common method involves the reaction of 1,6-hexanediol with hydrobromic acid in the presence of acid catalysts, where the hydroxyl groups are replaced by bromine atoms. Alternative industrial methods include radical bromination of hexane under controlled conditions to avoid over-bromination or side reactions. Reaction conditions, such as temperature and solvent choice, are optimized to produce the desired dihalide with high yield and minimal formation of mono- or poly-brominated byproducts.

1,6-Dibromohexane is widely used as a building block in the synthesis of polymers, especially polyamides and polyurethanes. Its terminal bromine atoms can undergo nucleophilic substitution with amines, thiols, or alcohols, forming linear or cross-linked polymeric structures. For instance, in the production of nylon-like materials, 1,6-dibromohexane reacts with diamines to form long-chain polyamides. Similarly, it is employed in the synthesis of epoxy resins and polyurethane prepolymers, where controlled substitution of bromine facilitates chain extension or cross-linking.

In addition to polymer synthesis, 1,6-dibromohexane serves as a precursor in the production of pharmaceuticals and agrochemicals. Its bifunctional nature allows chemists to introduce hexyl linkers or cyclic structures into target molecules, modifying physical properties such as solubility, hydrophobicity, and flexibility. The compound is particularly valuable for synthesizing macrocyclic structures or heterocycles, where the two reactive ends can undergo intramolecular reactions to form rings of defined size.

Mechanistic studies involving 1,6-dibromohexane focus on S_N2 nucleophilic substitution, where the primary bromides react readily with nucleophiles under mild conditions. Its symmetrical structure and primary bromides make it ideal for studying reaction kinetics, solvent effects, and competing elimination reactions. It is also used to investigate cross-linking efficiency in polymer formation, as both bromine atoms can participate in sequential or simultaneous substitution reactions.

Physically, 1,6-dibromohexane is slightly soluble in water but miscible with most organic solvents, including ethers, alcohols, and hydrocarbons. It is flammable and requires careful handling, including the use of personal protective equipment and storage in well-ventilated areas. Environmental precautions focus on preventing contamination of water and soil, as halogenated alkanes can be persistent and toxic to aquatic organisms.

Overall, 1,6-dibromohexane is a versatile chemical intermediate with wide-ranging applications in polymer chemistry, pharmaceuticals, and agrochemical synthesis. Its bifunctional reactivity, ease of substitution, and linear structure make it a valuable reagent for creating diverse chemical architectures and advancing both industrial and laboratory-scale chemical processes.

References

2024. Synthesis and Reactions of 2-Amino-3-Cyanopyridine Derivatives (A Review). Russian Journal of Organic Chemistry, 60(11).
DOI: 10.1134/s1070428024110113

2025. Smectic liquid crystalline poly(ester imide)s with low dielectric dissipation factors for high-frequency applications. Polymer Journal.
DOI: 10.1038/s41428-025-01020-0

2025. Reductive amination�engineered dual-function networks enhance alkaline stability and hydroxide conductivity in polyvinylpyrrolidone AEMs. Ionics.
DOI: 10.1007/s11581-025-06554-0