1-Bromo-2-chloro-4-iodo-3-methylbenzene: Key Facts & FAQs
1-Bromo-2-chloro-4-iodo-3-methylbenzene: Key Facts & FAQs
1-Bromo-2-chloro-4-iodo-3-methylbenzene is a polyhalogenated aromatic building block bearing three distinct halogen substituents and a methyl group on a benzene ring, making it a versatile intermediate for sequential, regioselective cross-coupling and other synthetic transformations in pharmaceutical and materials research.
- IUPAC Name
- 1-Bromo-2-chloro-4-iodo-3-methylbenzene
- SKU / Catalog Number
- B178661
- Molecular Formula
- C7H5BrClI
- Molecular Weight
- 331.37 g/mol
- Key Functional Handles
- Aryl bromide, aryl chloride, aryl iodide (three independent C–X bonds)
- Primary Application
- Regioselective cross-coupling reactions (e.g., Suzuki, Negishi, Sonogashira) and sequential functionalization
- Storage Recommendation
- Cool, dry, well-ventilated area; away from light and moisture
What Is 1-Bromo-2-chloro-4-iodo-3-methylbenzene?
1-Bromo-2-chloro-4-iodo-3-methylbenzene (catalog SKU B178661) is a polyhalogenated benzene derivative carrying bromine at position 1, chlorine at position 2, iodine at position 4, and a methyl group at position 3. The simultaneous presence of three different halogens on a single aromatic ring endows this compound with exceptional versatility in organic synthesis: each C–X bond exhibits a different intrinsic reactivity toward transition-metal catalysis and other coupling methods, enabling chemists to engage each halogen independently under carefully selected reaction conditions.
The compound belongs to the broader class of halogenated aromatic building blocks widely used in medicinal chemistry, agrochemical synthesis, and the preparation of functional materials such as conjugated polymers and liquid crystals. Its methyl substituent additionally provides a handle for benzylic functionalization or can serve as a directing group in certain electrophilic and metalation reactions.
Reactivity and Synthetic Applications
The three C–halogen bonds in this molecule differ markedly in their oxidative-addition kinetics with palladium and other transition-metal catalysts. In general, aryl iodides are the most reactive toward Pd(0)-catalyzed cross-coupling, followed by aryl bromides, and then aryl chlorides. This reactivity hierarchy allows synthetic chemists to perform sequential, chemoselective cross-coupling reactions — for example, first engaging the C–I bond in a Suzuki–Miyaura coupling, then the C–Br bond under modified conditions, and finally activating the less reactive C–Cl bond with more active catalyst systems (e.g., bulky phosphine or N-heterocyclic carbene ligands).
Typical transformations for which this building block is useful include:
- Suzuki–Miyaura coupling with arylboronic acids or esters to introduce aryl or heteroaryl groups.
- Negishi coupling with organozinc reagents for carbon–carbon bond formation.
- Sonogashira coupling to install terminal alkyne groups, useful in the synthesis of conjugated materials.
- Buchwald–Hartwig amination for the introduction of amine functionalities.
- Directed ortho-metalation facilitated by the methyl or halogen directing effects.
The methyl group can also be oxidized to a carboxylic acid, reduced to a methylene, or used as a radical acceptor under specific conditions, further expanding the synthetic utility of this scaffold.
Handling, Safety, and Storage
Like most polyhalogenated aromatic compounds, 1-Bromo-2-chloro-4-iodo-3-methylbenzene should be handled with appropriate precautions. Researchers should consult the full Safety Data Sheet (SDS) provided by Aladdin Scientific before use. General handling guidelines include:
- Use in a well-ventilated fume hood to minimize inhalation exposure.
- Wear appropriate personal protective equipment (PPE): nitrile gloves, laboratory coat, and safety glasses.
- Avoid contact with skin, eyes, and mucous membranes.
- Keep away from strong oxidizing agents, strong bases, and open flames.
For storage, keep the reagent in a tightly sealed container in a cool (typically 2–8 °C or room temperature as specified on the product label), dry, and well-ventilated location, away from light and moisture. Proper storage helps maintain purity and prevents decomposition or moisture uptake that could affect reaction outcomes.
Dispose of waste material in accordance with local, regional, and national regulations for halogenated organic waste.
Purity, Specifications, and Quality
Aladdin Scientific supplies 1-Bromo-2-chloro-4-iodo-3-methylbenzene (SKU B178661) as a research-grade reagent. Purity and specification details — including lot-specific certificates of analysis (CoA), NMR, GC purity data, and available pack sizes — can be found on the product page or obtained from Aladdin's technical support team.
When evaluating reagent quality for sensitive applications such as catalytic cross-coupling, researchers should pay attention to:
- Chemical purity (GC or HPLC): Higher purity minimizes side reactions from halogenated impurities.
- Water content: Moisture can interfere with metal-catalyzed reactions and should be checked if the reagent is used in anhydrous conditions.
- Appearance: The compound is expected to be a solid or liquid (verify on the CoA) at room temperature; any unusual coloration may indicate degradation.
For questions about specific lot purity, availability, or bulk pricing, please contact Aladdin Scientific's customer service or your regional sales representative.
Ordering and Availability
1-Bromo-2-chloro-4-iodo-3-methylbenzene is available from Aladdin Scientific under catalog number B178661. To place an order:
- Visit the Aladdin Scientific website and search by product name or catalog number B178661.
- Select the desired pack size and quantity, then add to your cart.
- For institutional purchase orders, blanket orders, or volume discounts, contact the Aladdin sales team directly.
- Expedited shipping options may be available depending on your location and local regulatory requirements for shipping halogenated compounds.
If the product is temporarily out of stock, Aladdin Scientific's customer service team can provide estimated restock timelines or suggest structurally related alternatives. Always verify the regulatory import requirements for halogenated aromatic compounds in your country before ordering internationally.
Frequently asked questions
What makes 1-Bromo-2-chloro-4-iodo-3-methylbenzene useful in cross-coupling chemistry?
The compound contains three distinct C–halogen bonds (C–I, C–Br, C–Cl) that differ in reactivity toward transition-metal catalysts, allowing chemists to perform sequential, regioselective cross-coupling reactions at each site independently. This makes it an especially powerful building block for constructing complex, multi-substituted arene scaffolds in a controlled, stepwise manner.
In what order should the three halogen positions be engaged in sequential cross-coupling?
As a general rule, the aryl iodide (C–I) is engaged first due to its highest reactivity toward Pd(0) oxidative addition, followed by the aryl bromide (C–Br), and finally the aryl chloride (C–Cl), which typically requires a more active catalyst system such as Pd with bulky phosphine or NHC ligands. Reaction conditions should be optimized for each step to ensure chemoselectivity.
What safety precautions should I take when handling this compound?
Always handle 1-Bromo-2-chloro-4-iodo-3-methylbenzene in a well-ventilated fume hood while wearing appropriate PPE including nitrile gloves, a laboratory coat, and safety glasses. Avoid skin, eye, and inhalation exposure, and consult the full Safety Data Sheet (SDS) from Aladdin Scientific before use. Dispose of waste according to local regulations for halogenated organic compounds.
How should I store 1-Bromo-2-chloro-4-iodo-3-methylbenzene to maintain its purity?
Store the reagent in a tightly sealed container in a cool, dry, well-ventilated location away from direct light and moisture. Refer to the product label or Certificate of Analysis for the specific recommended storage temperature. Exposure to moisture or elevated temperatures may lead to degradation and affect reaction performance.
Can the methyl group on this compound be further functionalized?
Yes. The benzylic methyl group can be oxidized to an aldehyde or carboxylic acid using appropriate oxidants, halogenated at the benzylic position via radical bromination, or subjected to directed metalation under strong base conditions. These transformations extend the synthetic versatility of the scaffold beyond the three C–halogen handles.
How do I confirm the identity and purity of the received product?
Aladdin Scientific provides a Certificate of Analysis (CoA) for each lot, which typically includes GC purity, NMR data, and physical characterization. You can request the CoA through the product page or customer service. For additional confirmation, 1H NMR, 13C NMR, and mass spectrometry are standard analytical methods for verifying the identity and purity of aryl halide building blocks.
References
- Negishi, E. (Ed.). Handbook of Organopalladium Chemistry for Organic Synthesis. Wiley-Interscience, 2002. (General reference for Pd-catalyzed cross-coupling reactions including chemoselectivity of aryl halides.)
- Beletskaya, I. P.; Cheprakov, A. V. The Heck Reaction as a Sharpening Stone of Palladium Catalysis. Chem. Rev. 2000, 100, 3009–3066. (Background on aryl halide reactivity trends in Pd catalysis.) doi:10.1021/cr9903048
- Aladdin Scientific. Product Page: 1-Bromo-2-chloro-4-iodo-3-methylbenzene, SKU B178661. (Primary source for product specifications, CoA, and SDS.)
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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