2-Chlorobutane
[CAS# 78-86-4]

Identification

• Classification: Chemical reagent >> Organic reagent >> Halogenated aliphatic hydrocarbon
• Name: 2-Chlorobutane
• Synonyms: sec-Butyl chloride
• Molecular Formula: C₄H₉Cl
• Molecular Weight: 92.56
• CAS Registry Number: 78-86-4
• EC Number: 201-151-7
• SMILES: CCC(C)Cl

Properties

• Density: 0.87
• Melting point: -140 °C
• Boiling point: 68-70 °C
• Refractive index: 1.396-1.398
• Flash point: -15 °C
• Water solubility: immiscible

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS07 Danger
• Risk Statements: H225-H290-H315-H319-H335-H412
• Safety Statements: P210-P233-P234-P240-P241-P242-P243-P261-P264-P264+P265-P271-P273-P280-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P370+P378-P390-P403+P233-P403+P235-P405-P406-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 1127

Discovery and Applications

2-Chlorobutane, a secondary alkyl halide, was first synthesized in the 19th century during the burgeoning exploration of organic chemistry. The chemical formula for 2-Chlorobutane is C4H9Cl, featuring a four-carbon chain with a chlorine atom attached to the second carbon. This compound was identified through the reaction of butane with chlorine under controlled conditions, typically involving light or heat to facilitate the halogenation process. The resulting compound was notable for its structural isomerism with 1-Chlorobutane, leading to a deeper understanding of positional isomerism and its effects on chemical properties and reactivity.

2-Chlorobutane is widely used as an intermediate in organic synthesis. Its structure makes it suitable for various substitution and elimination reactions. In nucleophilic substitution reactions, 2-Chlorobutane can form a variety of secondary alcohols, ethers, and other functionalized compounds.

2-Chlorobutane's moderate polarity allows it to function as a solvent and extraction agent for different organic compounds. It is used in the formulation of coatings, adhesives, and sealants where its solvency properties help in dissolving resins and polymers. Additionally, it aids in the purification of chemical products through selective extraction processes.

In the production of more complex chemicals, 2-Chlorobutane serves as a valuable intermediate. It is involved in manufacturing plasticizers, surfactants, and other industrial chemicals. For example, its reaction with nucleophiles can produce secondary amines, which are important building blocks in the chemical industry.

In chemical research, 2-Chlorobutane is used to study reaction mechanisms and the behavior of secondary alkyl halides. Its relatively simple structure makes it an excellent model compound for educational purposes and experimental studies in organic chemistry. Researchers utilize it to understand the kinetics and dynamics of substitution and elimination reactions.

The pharmaceutical industry employs 2-Chlorobutane in the synthesis of active pharmaceutical ingredients (APIs) and intermediates.The reactivity of 2-Chlorobutane allows for the introduction of various functional groups necessary for drug efficacy and bioavailability.

References

2023. Cl atoms-initiated degradation of 1-Chlorobutane and 2-Chlorobutane: Kinetics, product analysis and atmospheric implications. Chemosphere, 340.
DOI: 10.1016/j.chemosphere.2023.139664

2017. Gas-chromatographic separation of enantiomers of 2-chlorobutane and 2-bromobutane on a cyanuric acid-modified Carboblack C adsorbent. Journal of Analytical Chemistry, 72(10).
DOI: 10.1134/s1061934817100069

2019. Separating Enantiomers of Haloalkanes and Alcohols on a Stationary Phase Based on the Supramolecular Structure of Melamine with Induced Chirality. Russian Journal of Physical Chemistry A, 93(6).
DOI: 10.1134/s0036024419060116