1-Chlorooctane
[CAS# 111-85-3]

Identification

• Classification: Chemical reagent >> Organic reagent >> Halogenated aliphatic hydrocarbon
• Name: 1-Chlorooctane
• Synonyms: 1-Octylchloride
• Molecular Formula: C₈H₁₇Cl
• Molecular Weight: 148.67
• CAS Registry Number: 111-85-3
• EC Number: 203-915-5
• SMILES: CCCCCCCCCl

Properties

• Density: 0.9±0.1 g/cm³ Calc.^*, 0.875 g/mL (Expl.)
• Melting point: -61 °C (Expl.)
• Boiling point: 181.9±3.0 °C 760 mmHg (Calc.)^*, 183 °C (Expl.)
• Flash point: 57.8 °C (Calc.)^*, 61 °C (Expl.)
• Solubility: water 0.02 g/L (Expl.)
• Index of refraction: 1.425 (Calc.)^*, 1.43 (Expl.)

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

Safety Data

• Hazard Symbols: GHS08;GHS09 Danger
• Risk Statements: H304-H400-H410-H411
• Safety Statements: P273-P301+P316-P331-P391-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Aspiration hazard	Asp. Tox.	1	H304
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315

• Transport Information: UN 1993

Discovery and Applications

1-Chlorooctane is a primary alkyl halide with the molecular formula C₈H₁₇Cl. It is a colorless liquid at ambient temperature, exhibiting a mild, characteristic odor typical of linear chloroalkanes. The compound belongs to the family of straight-chain primary chloroalkanes, where the chlorine atom is attached to the terminal carbon of an eight-carbon chain. Its discovery and study were part of the broader nineteenth- and early twentieth-century exploration of organohalogen chemistry, during which chemists investigated the reactivity and synthesis of halogenated hydrocarbons as fundamental building blocks for organic synthesis.

1-Chlorooctane is commonly prepared through the reaction of 1-octanol with thionyl chloride, phosphorus pentachloride, or other halogenating agents, which convert the alcohol into a chlorinated derivative. These methods exemplify classical substitution reactions and illustrate the predictable chemical behavior of primary alcohols when transformed into alkyl chlorides. Alternative syntheses involve free radical chlorination of octane under controlled conditions to preferentially yield the terminal chloro compound. The reproducibility of these reactions has allowed chemists to obtain 1-chlorooctane in high purity, making it suitable for both laboratory and industrial applications.

The chemical reactivity of 1-chlorooctane primarily derives from the presence of the chlorine atom, which is a suitable leaving group in nucleophilic substitution reactions. This enables the compound to act as an alkylating agent, allowing the introduction of an octyl group into a variety of nucleophilic substrates. As a result, 1-chlorooctane is widely used in the preparation of ethers, amines, thiols, and other functional derivatives, providing a versatile tool for synthetic chemists seeking to modify molecules with a linear C₈ moiety.

In industrial and applied chemistry, 1-chlorooctane serves as an intermediate in the synthesis of surfactants, lubricants, and specialty chemicals. Octyl-substituted amines and quaternary ammonium salts derived from this compound exhibit surfactant properties, influencing hydrophobicity and emulsifying behavior in formulations. Its incorporation into materials chemistry allows the modulation of physical and chemical properties, making it valuable in coatings, plasticizers, and other applications that require controlled hydrophobic interactions.

1-Chlorooctane is also of interest in mechanistic studies of organic reactions. As a primary chloride, it provides a model for understanding nucleophilic substitution (S_N2) and elimination (E2) mechanisms. Kinetic studies have been conducted to explore solvent effects, nucleophile strength, and steric influences on reaction pathways. Comparisons with secondary and tertiary chlorides have further enhanced the understanding of structure–reactivity relationships in organohalogen chemistry.

Physically, 1-chlorooctane is relatively dense, immiscible with water, and soluble in organic solvents such as ether, ethanol, and benzene. Its boiling point is elevated compared to octane due to the polarizability of the chlorine atom, a characteristic shared across the series of alkyl chlorides. These properties are significant for solvent selection, partitioning studies, and purification processes in both laboratory and industrial settings.

Safety and handling considerations are critical when working with 1-chlorooctane. Like other alkyl chlorides, it can cause irritation to the skin, eyes, and respiratory system. Prolonged or repeated exposure may affect the liver, kidneys, and central nervous system. Consequently, proper ventilation, personal protective equipment, and adherence to chemical safety protocols are essential. Environmental management is also important due to the persistence and bioaccumulative potential of chlorinated hydrocarbons.

The discovery and application of 1-chlorooctane underscore its role as a fundamental organochlorine reagent. It has facilitated the construction of numerous chemical structures and continues to serve as a key intermediate in synthetic organic chemistry, industrial processes, and materials development. Its combination of chemical reactivity, physical properties, and versatility ensures its ongoing relevance in both research and applied chemical production.

References

2023. CO2 Adsorption. Journal of Porous Materials, 30(5).
DOI: 10.1007/s10934-023-01503-6

2021. Organotin Synthesis. Main Group Metal Chemistry, 44(1).
DOI: 10.1134/s2070050421030107

2023. Fluorescent Probe. Analytical and Bioanalytical Chemistry, 415(12).
DOI: 10.1007/s00216-023-04623-9