2-Bromo-N,N-dimethylethylamine hydrobromide
[CAS 2862-39-7]

Identification

• Classification: Chemical reagent >> Organic reagent >> Amine salt (ammonium salt)
• Name: 2-Bromo-N,N-dimethylethylamine hydrobromide
• Synonyms: (2-bromoethyl)dimethylamine hydrobromide
• Molecular Formula: C₄H₁₀₂N.HBr
• Molecular Weight: 232.94
• CAS Registry Number: 2862-39-7
• EC Number: 220-680-4
• SMILES: CN(C)CCBr.Br

Properties

• Solubility: water: soluble 0.915 mg/mL (Expl.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Eye irritation	Eye Irrit.	2A	H319

Discovery and Applications

2-Bromo-N,N-dimethylethylamine hydrobromide is a quaternary ammonium salt derived from a bromo-substituted dimethylaminoethyl amine framework. Structurally, it consists of an ethyl chain bearing a bromine substituent at the 2-position and a terminal dimethylammonium group, with hydrobromide serving as the counterion. Compounds of this type are commonly encountered as reactive alkylating agents or intermediates in organic synthesis involving nitrogen-containing functional groups.

The chemistry of haloalkyl amines is closely tied to the development of alkylation reactions in organic chemistry, where electrophilic carbon centers bearing halogens can undergo nucleophilic substitution. The presence of a bromine atom on the ethyl chain makes the molecule highly reactive toward nucleophiles, as carbon–bromine bonds are relatively labile and susceptible to displacement. This reactivity is a central feature in the use of such compounds as intermediates for introducing aminoethyl groups into more complex molecules.

The dimethylamino functionality is a tertiary amine that can be protonated to form the corresponding ammonium salt under acidic conditions, which is reflected in the hydrobromide form of the compound. Protonation increases the compound’s ionic character and water solubility, which can influence handling, stability, and reactivity in solution. In its protonated form, the nitrogen center is quaternary in nature, carrying a positive charge that is balanced by the bromide counterion.

Compounds containing both a halogenated carbon chain and an amine or ammonium group are often used as building blocks in the synthesis of more complex nitrogen-containing molecules. The electrophilic carbon adjacent to the bromine atom can undergo nucleophilic substitution reactions with amines, thiols, alcohols, or other nucleophiles, leading to the formation of substituted ethylamine derivatives. This type of reactivity is widely exploited in the preparation of surfactants, pharmaceuticals, and functionalized polymers.

The presence of both a positively charged ammonium group and a good leaving group within the same molecular framework introduces a high degree of chemical reactivity. Such compounds can undergo intramolecular or intermolecular transformations depending on reaction conditions, often leading to the formation of more stable substituted amines after displacement of the halide.

From a physicochemical perspective, 2-bromo-N,N-dimethylethylamine hydrobromide is expected to be a polar, ionic solid with high solubility in water and other polar solvents. The ionic nature arises from the protonated amine and associated bromide counterion, while the organic backbone provides limited hydrophobic character. This combination of properties is typical of small quaternary ammonium salts used in synthetic chemistry.

The synthesis of haloalkyl amine salts generally involves the reaction of dimethylaminoethanol derivatives with brominating agents or through substitution reactions on pre-activated haloalkyl precursors. The formation of the hydrobromide salt is typically achieved by treatment with hydrobromic acid, which protonates the amine and stabilizes the compound in solid form.

In synthetic applications, such compounds are often used as alkylating reagents to introduce dimethylaminoethyl groups into target molecules. The dimethylamino group can later serve as a handle for further functionalization, protonation, or quaternization, making it useful in the construction of cationic surfactants, ionic liquids, and biologically active compounds.

Overall, 2-bromo-N,N-dimethylethylamine hydrobromide is a reactive haloalkyl ammonium salt characterized by a nucleophile-sensitive carbon–bromine bond and a protonated dimethylamino group. Its significance lies in its role as a versatile intermediate in organic synthesis, particularly in the preparation of functionalized amines and quaternary ammonium-containing compounds used in chemical and materials applications.

References

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