3-(Chloromethyl)heptane
[CAS# 123-04-6]

Identification

• Classification: Chemical reagent >> Organic reagent >> Halogenated aliphatic hydrocarbon
• Name: 3-(Chloromethyl)heptane
• Synonyms: 2-Ethylhexylchloride; Isooctylchloride
• Molecular Formula: C₈H₁₇Cl
• Molecular Weight: 148.67
• CAS Registry Number: 123-04-6
• EC Number: 204-594-4
• SMILES: CCCCC(CC)CCl

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*, 0.882 g/mL (Expl.)
• Melting point: -70 ºC (Expl.)
• Boiling point: 173.4±8.0 ºC 760 mmHg (Calc.)^*, 172 ºC (Expl.)
• Flash point: 52.5±16.5 ºC (Calc.)^*, 60 ºC (Expl.)
• Solubility: water 0.0503 g/L (20 ºC) (Expl.)
• Index of refraction: 1.423 (Calc.)^*, 1.432-1.436 (Expl.)

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

Safety Data

• Hazard Symbols: GHS02;GHS07;GHS09 WarningGHS02
• Hazard Statements: H226-H315-H317-H400-H410-H413
• Precautionary Statements: P210-P233-P240-P241-P242-P243-P261-P264-P272-P273-P280-P302+P352-P303+P361+P353-P321-P332+P317-P333+P317-P362+P364-P370+P378-P391-P403+P235-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	4	H413
Skin sensitization	Skin Sens.	1B	H317
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

3-(Chloromethyl)heptane is a branched primary alkyl chloride with the molecular formula C₈H₁₇Cl. It is a colorless to pale yellow liquid, known for its reactivity as an intermediate in organic synthesis. The compound belongs to the class of haloalkanes, specifically featuring a chlorine atom attached to a secondary carbon via a chloromethyl group, which imparts notable electrophilic character to the molecule and facilitates nucleophilic substitution reactions.

The synthesis of 3-(chloromethyl)heptane typically involves the halogenation of the corresponding alcohol, 3-(hydroxymethyl)heptane, using chlorinating agents such as thionyl chloride, phosphorus trichloride, or other suitable reagents. Alternative methods include radical chlorination of branched alkanes under controlled conditions, where selectivity for the chloromethyl group is achieved through careful temperature and reagent management. These synthetic approaches provide a reliable route to high-purity product suitable for laboratory and industrial use.

The chemical reactivity of 3-(chloromethyl)heptane is dominated by the chloromethyl group, which acts as an excellent leaving group in S_N2 reactions. This allows the molecule to undergo substitution with a variety of nucleophiles, including amines, thiols, alcohols, and carboxylates, yielding heptane derivatives with functionalized side chains. Its reactivity profile makes it a valuable intermediate for the preparation of surfactants, pharmaceuticals, agrochemicals, and specialty organic compounds.

In industrial and laboratory applications, 3-(chloromethyl)heptane is frequently used as a building block in the synthesis of complex organic molecules. It can be transformed into amines, ethers, esters, and other functional derivatives, which find applications in drug development, polymer chemistry, and the production of chemical additives. The compound’s branched structure and chloromethyl functionality provide specific chemical and steric properties, which are exploited to tailor the physical and biological characteristics of the resulting derivatives.

From a mechanistic perspective, 3-(chloromethyl)heptane serves as an important model for studying nucleophilic substitution reactions at primary and secondary positions. Its structure allows chemists to examine how chain branching and steric hindrance influence reaction rates and product distributions. Such studies contribute to a broader understanding of reactivity trends in haloalkanes and inform the design of synthetic routes for more complex molecules.

Physically, 3-(chloromethyl)heptane is insoluble in water but miscible with organic solvents such as ether, chloroform, and alcohols. It has a moderate boiling point due to van der Waals interactions along the hydrocarbon chain. Safety and environmental considerations are important when handling this compound. It is corrosive and can cause irritation to the skin, eyes, and respiratory system. Appropriate protective equipment, proper ventilation, and adherence to chemical safety protocols are essential to mitigate exposure. Environmental management is also necessary due to its potential toxicity to aquatic life and persistence in the environment.

The discovery and continued use of 3-(chloromethyl)heptane highlight its utility as a versatile intermediate in organic chemistry. Its ability to undergo selective nucleophilic substitution reactions, combined with its branched structure, makes it an important reagent for synthesizing a wide array of derivatives for industrial, pharmaceutical, and research applications. The compound’s chemical behavior and functional versatility ensure its ongoing relevance in modern synthetic and applied chemistry.

References

2022. Preparation of Organosodium Compounds by Flow System. Synfacts, 18(8).
DOI: 10.1055/s-0041-1737693

2021. Bromine-Sodium Exchange and Directed Metalations in Continuous Flow. Synfacts, 17(8).
DOI: 10.1055/s-0040-1706221

1996. NMR spectra of a hydrocarbon-soluble organosodium compound and its lithium analogs. Russian Chemical Bulletin, 45(4).
DOI: 10.1007/bf01431309