Lauroyl Chloride (Dodecanoyl Chloride) CAS 112-16-3
Lauroyl Chloride (Dodecanoyl Chloride): Properties and Applications
1. Introduction
Lauroyl chloride, also known as dodecanoyl chloride, is an acyl chloride derived from lauric acid (C12). It is a versatile and highly reactive compound widely used in organic synthesis, surfactant production, and various industrial processes. Its high electrophilicity makes it an excellent acylating agent for introducing the lauroyl group into a wide range of molecules, enabling the synthesis of esters, amides, and other derivatives.
2. Chemical Structure and Nomenclature
IUPAC name: Dodecanoyl chloride
Molecular formula: C₁₂H₂₃ClO (CH₃(CH₂)₁₀COCl)
Molecular weight: 218.76 g/mol
CAS number: 112-16-3
EC number: 203-941-7
Synonyms: Lauroyl chloride, dodecanoyl chloride, lauryl chloride (not to be confused with the chloroalkane C₁₂H₂₅Cl)
Appearance: Colorless to pale yellow clear liquid
3. Physicochemical Properties
Density: 0.920–0.946 g/mL at 25°C
Boiling point: 134–137°C at 11 mmHg; 266.6°C at 760 mmHg
Melting point: –17°C to –13°C
Flash point: 106–140°C
Refractive index: 1.440–1.446
Solubility: Reacts with water (hydrolysis); miscible with organic solvents (benzene, toluene, hexane, chloroform)
Purity: Typically ≥98.0% (GC)
Reactivity: As a typical acyl chloride, lauroyl chloride readily reacts with alcohols and phenols to form esters (laurates), with amines to form amides, and with water to hydrolyze to lauric acid and hydrochloric acid. It is highly reactive and should be stored under inert gas.
4. Synthesis Methods
Lauroyl chloride is typically produced by the chlorination of lauric acid using thionyl chloride (SOCl₂), phosphorus pentachloride (PCl₅), or phosphorus trichloride (PCl₃):
C₁₂H₂₅COOH + SOCl₂ → C₁₂H₂₃COCl + SO₂ + HCl
The reaction is carried out at controlled temperatures (50–80°C) with removal of gaseous by-products. The product is purified by vacuum distillation to remove unreacted starting materials and by-products.
5. Applications
Organic synthesis: Lauroyl chloride is a versatile acylating agent used to introduce the lauroyl group (C₁₂H₂₃CO–) into various molecules. It is widely employed in the synthesis of esters, amides, and other derivatives.
Surfactant production: Reaction with amino acids (e.g., sarcosine) yields mild surfactants such as lauroyl sarcosinates, used in shampoos, shower gels, and baby care products.
Nanocellulose modification: Used as a tailoring agent for the chemical modification of nanocelluloses of different lengths, nanofibrillated cellulose, and cellulose nanocrystals.
Collagen acylation: Employed in the preparation of acylated collagen with improved water solubility and surface activity.
Chitosan modification: Converts chitosan into acylated chitosan derivatives with increased solubility in organic solvents.
Pharmaceuticals: Used as an intermediate in the synthesis of various pharmaceutical compounds, including labeled analogues for metabolic studies.
Cosmetics and personal care: Serves as a key raw material for the synthesis of emollients, emulsifiers, and other cosmetic ingredients.
Boundary lubricants: Used in the preparation of novel polyvinyl boundary lubricants.
6. Safety and Toxicology
Hazards: Lauroyl chloride is a corrosive and toxic substance. It causes severe skin burns and eye damage (H314). Harmful if swallowed (H302). Contact with water liberates toxic gas (EUH029).
Inhalation: Causes severe irritation of the respiratory tract and may be fatal due to spasm, inflammation, and edema of the larynx and bronchi, chemical pneumonitis, or pulmonary edema.
First aid: In case of skin contact, wash immediately with plenty of water. For eye contact, rinse thoroughly with water for at least 15–20 minutes and seek medical attention. If inhaled, move to fresh air and seek medical help.
Storage: Store in a cool, dry, well-ventilated place, in tightly sealed containers, under inert gas. Protect from moisture and incompatible materials (strong oxidizers, bases, alcohols, amines).
Disposal: Small quantities can be quenched with aqueous sodium hydroxide or sodium carbonate solution, followed by neutralization and safe disposal of the resulting salts. Large volumes must be disposed of in accordance with local environmental regulations.
7. Conclusion
Lauroyl chloride (dodecanoyl chloride, CAS 112-16-3) is a highly reactive acyl chloride and a versatile building block for organic synthesis. Its applications span the production of surfactants, cosmetics, pharmaceuticals, and functional materials, as well as the chemical modification of biopolymers such as nanocellulose, chitosan, and collagen. Due to its corrosive and toxic nature, strict safety precautions must be observed when handling this compound. Proper storage, personal protective equipment, and adherence to safety protocols are essential to ensure safe use.