Chemical Identity and Structural Features

1,3-Dibromo-2,4-dimethoxybenzene (CAS number to be verified; Aladdin SKU D770520) is an ortho-substituted benzene derivative in which bromine atoms occupy the 1- and 3-positions while methoxy groups are located at the 2- and 4-positions. This alternating pattern of electron-withdrawing (C–Br) and electron-donating (–OCH3) substituents creates a polarized π-system with distinct reactivity at each halogenated carbon.

The molecular formula is C₈H₈Br₂O₂, corresponding to a molecular weight of approximately 295.96 g/mol. The presence of two aryl bromide handles distinguishes it from mono-brominated analogues and enables sequential or double functionalization in multi-step synthetic sequences. The flanking methoxy groups exert a combined inductive and resonance influence that modulates the electron density at the ipso carbons, affecting both reactivity rates in oxidative addition steps and regioselectivity in directed metalation protocols.

Synthetic Applications and Reactivity

The two aryl C–Br bonds in 1,3-Dibromo-2,4-dimethoxybenzene are competent electrophiles in a broad range of transition-metal-catalyzed transformations. In palladium-catalyzed Suzuki–Miyaura coupling, each bromide can react with aryl- or alkenylboronic acids to introduce carbon-based fragments with high selectivity. Similarly, Negishi coupling with organozinc reagents and Buchwald–Hartwig amination expand access to biaryl and aminoaryl products respectively.

Directed ortho-metalation (DoM) is an additional strategy enabled by the methoxy directing groups. Treatment with strong alkyllithium bases (e.g., n-BuLi) at low temperature can generate aryllithium intermediates at positions flanked by the –OCH3 groups, providing a handle for subsequent electrophilic quench with carbonyl compounds, silyl chlorides, or other electrophiles. Sequential mono-selective coupling followed by a second cross-coupling step allows construction of unsymmetrical 1,3-diaryl-2,4-dimethoxybenzene scaffolds valuable in materials science and medicinal chemistry.

The compound is also relevant as a precursor in the synthesis of extended π-conjugated systems, including oligophenylenes and donor–acceptor architectures used in organic electronics research.

Handling, Safety, and Storage

As with all organobromine aromatic compounds, 1,3-Dibromo-2,4-dimethoxybenzene should be handled in a well-ventilated fume hood using appropriate personal protective equipment (PPE), including nitrile gloves, safety glasses, and a laboratory coat. Avoid inhalation of dust or vapors and contact with skin and eyes.

The compound should be stored in a tightly sealed container in a cool, dry location, away from moisture, strong oxidizing agents, and sources of ignition. Long-term storage under inert atmosphere (nitrogen or argon) is recommended to prevent hydrolysis of the aryl bromide bonds or oxidative degradation.

Users should consult the Safety Data Sheet (SDS) provided by Aladdin Scientific before first use. Waste disposal must comply with local regulations governing halogenated organic compounds.

Note: Specific GHS hazard classifications, flash point, and LD₅₀ values are not confirmed in the current source material and should be verified against the official SDS prior to use.

Procurement and Quality Considerations

1,3-Dibromo-2,4-dimethoxybenzene is available from Aladdin Scientific under catalog number D770520. Researchers are advised to confirm purity specifications (e.g., GC purity ≥97%) at the time of ordering, as purity directly impacts yields in sensitive cross-coupling reactions.

An equivalent product is also listed by McLean (麦克林) under catalog number D926732, which may serve as an alternative source for procurement comparison. When switching suppliers, users should verify that CAS numbers, structural confirmation data (NMR, HRMS), and purity certificates align before substituting in validated synthetic protocols.

For bulk quantities or custom purity grades, laboratory managers are encouraged to contact Aladdin Scientific's technical sales team directly. Proper chain-of-custody documentation and certificates of analysis (CoA) should be requested and retained for regulatory compliance and reproducibility records.