Benzyltrimethylammonium tribromide
[CAS# 111865-47-5]

Identification

• Classification: Chemical reagent >> Organic reagent >> Amine salt (ammonium salt)
• Name: Benzyltrimethylammonium tribromide
• Synonyms: Benzyltrimethylammonium bromide dibromide
• Molecular Formula: C₁₀H₁₆Br₃N
• Molecular Weight: 389.95
• CAS Registry Number: 111865-47-5
• EC Number: 629-289-7
• SMILES: C[N+](C)(C)CC1=CC=CC=C1.Br[Br-]Br

Properties

• Melting point: 99-101 °C (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

Benzyltrimethylammonium tribromide (C7H10Br3N) is a quaternary ammonium salt, consisting of a benzyl group attached to a trimethylammonium cation (C6H5CH2N+(CH3)3) and three bromide anions (Br−). It is typically synthesized through the reaction of benzyltrimethylammonium chloride with a source of bromine, such as sodium bromide or hydrobromic acid.

Benzyltrimethylammonium tribromide is primarily used as a phase transfer catalyst in organic synthesis. Phase transfer catalysts are compounds that facilitate the transfer of a reactant from one phase to another, often between aqueous and organic solvents, thereby increasing the efficiency of a reaction. The quaternary ammonium ion in benzyltrimethylammonium tribromide allows it to solvate anionic reactants and transport them into organic solvents, where they are otherwise insoluble.

In synthetic chemistry, it is employed in various reactions, including nucleophilic substitutions and electrophilic aromatic substitutions. Its ability to facilitate reactions between anions in different phases makes it useful in a range of synthetic processes, especially when dealing with poorly soluble reactants. One notable application is in the synthesis of alkyl and aryl halides, where it can help to enhance the reactivity of halide anions in substitution reactions.

Benzyltrimethylammonium tribromide is also used in the synthesis of other organic compounds, particularly in the preparation of benzyl and other substituted derivatives, as well as in the development of novel catalytic processes. Additionally, it has been employed in research for its potential as a versatile reagent in diverse synthetic pathways, due to its unique solubility properties and its ability to facilitate the movement of charged species between different solvent phases.

In summary, benzyltrimethylammonium tribromide is an important reagent in organic chemistry, known for its role as a phase transfer catalyst. Its applications are primarily in reactions requiring the transfer of anionic species between different phases, significantly enhancing the efficiency of many synthetic processes.

References

2024. Revised data for the reaction of benzyltrimethylammonium tribromide with sterically hindered p-cresols. Russian Chemical Bulletin.
DOI: 10.1007/s11172-024-4210-1

2016. Phenyl trimethyl ammonium tribromide mediated robust one-pot synthesis of spiro-oxacycles - an economic route - stereoselective synthesis of oxaspirohexacyclodieneones. Organic & Biomolecular Chemistry, 14(32).
DOI: 10.1039/C6OB01116K