Chemical Identity and Physical Properties

1-Bromo-2,3-dimethylbenzene (CAS 576-23-8), also referred to as 2,3-dimethylbromobenzene or 2-bromo-1,3-dimethylbenzene in some older literature, belongs to the class of ortho-substituted aryl bromides. Its molecular formula is C₈H₉Br with a molecular weight of approximately 185.06 g/mol. The compound presents as a colorless to pale yellow liquid at room temperature. The two methyl groups at the 2- and 3-positions create steric congestion adjacent to the bromine substituent, a feature that influences its reactivity in metal-catalyzed coupling reactions and directs regioselectivity in further electrophilic aromatic substitution. Key physicochemical parameters such as exact boiling point, density, and refractive index should be verified against the certificate of analysis (CoA) supplied with each lot of SKU B101911.

Synthetic Applications

As a sterically hindered aryl bromide, 1-bromo-2,3-dimethylbenzene serves several important roles in preparative organic chemistry:

• Palladium-Catalyzed Cross-Coupling: The C–Br bond can participate in Suzuki–Miyaura, Negishi, Stille, and Kumada coupling reactions to introduce the 2,3-dimethylphenyl moiety onto diverse carbon frameworks. Bulky phosphine ligands (e.g., SPhos, XPhos) are often required to achieve acceptable yields with sterically hindered substrates.
• Grignard Reagent Preparation: Treatment with magnesium in anhydrous THF or diethyl ether yields the corresponding arylmagnesium bromide, which can be used in nucleophilic additions to aldehydes, ketones, esters, and other electrophiles.
• Directed ortho-Metalation and Lithiation: Halogen–metal exchange with n-BuLi or t-BuLi at low temperature (–78 °C) generates a transient aryllithium species for subsequent reactions with electrophiles.
• Transition-Metal-Catalyzed C–H Functionalization: The compound can serve as a coupling partner in C–H activation strategies, providing access to complex biaryl and heterobiaryl architectures relevant to pharmaceuticals and materials science.

Researchers designing multi-step syntheses should account for the steric influence of the flanking methyl groups, which may necessitate elevated temperatures or specialized catalyst systems.

Safety, Handling and Storage Guidelines

1-Bromo-2,3-dimethylbenzene is a halogenated organic liquid and should be handled with appropriate precautions:

• Personal Protective Equipment (PPE): Wear chemical-resistant gloves (nitrile or neoprene), safety goggles, and a lab coat. Work in a fume hood to avoid inhalation of vapors.
• Flammability: The compound is potentially flammable. Keep away from open flames, sparks, and other ignition sources. Consult the Safety Data Sheet (SDS) for the specific flash point before use.
• Skin and Eye Contact: May cause irritation. In case of contact, flush immediately with copious water for at least 15 minutes and seek medical advice.
• Storage: Store in a tightly sealed container in a cool (below 25 °C), dry, and well-ventilated location, away from light and incompatible materials such as strong oxidizers and strong bases.
• Disposal: Dispose of waste in accordance with local, national, and institutional regulations for halogenated organic solvents. Do not pour down the drain.

Always consult the current SDS for SKU B101911 before first use. SDS documents are available from Aladdin Scientific upon request or via the product page.

Quality, Purity and Specification Considerations

For demanding synthetic applications, reagent purity is critical. When ordering 1-bromo-2,3-dimethylbenzene (SKU B101911) from Aladdin Scientific, researchers should consider the following:

• Purity Grade: Confirm the stated purity (typically assessed by GC) on the product specification sheet and CoA. Higher purity grades minimize the introduction of regioisomeric impurities (e.g., 1-bromo-2,4-dimethylbenzene) that could complicate downstream purification.
• Lot-to-Lot Consistency: Request a CoA for each lot, especially for regulated research or scale-up work. Key parameters typically include GC purity, water content (Karl Fischer), and appearance.
• Regioisomeric Purity: Because several dimethylbromobenzene isomers exist, confirm the correct regiochemistry (1-bromo-2,3-substitution pattern) by NMR or GC-MS if the application is sensitive to isomeric contamination.
• Packaging: Available in various package sizes to support both discovery-scale and larger preparative work. Contact Aladdin Scientific procurement for bulk or custom packaging inquiries.