1-(2-Bromo-5-chlorophenyl)ethanone: Properties & Lab Use

1-(2-Bromo-5-chlorophenyl)ethanone is a halogenated aromatic ketone widely employed as a versatile synthetic building block in medicinal chemistry and fine chemical research.

CAS Number

1006-40-2

Molecular Formula

C₈H₆BrClO

Molecular Weight

233.49 g/mol

Aladdin SKU

B400833

Appearance

Solid (typically pale yellow to off-white powder or crystals)

Key Functional Groups

Aryl ketone (C=O), aryl bromide (C–Br), aryl chloride (C–Cl)

Chemical Identity and Structure

1-(2-Bromo-5-chlorophenyl)ethanone (CAS 1006-40-2, Aladdin SKU B400833) is an acetophenone derivative bearing two halogen substituents on the phenyl ring: a bromine atom at the ortho position (C-2) and a chlorine atom at the para position relative to bromine (C-5). Its molecular formula is C₈H₆BrClO and its molecular weight is approximately 233.49 g/mol. The compound contains three reactive handles—a carbonyl group, an aryl bromide, and an aryl chloride—making it a particularly attractive multifunctional building block for synthetic chemistry.

The ortho-bromine substituent confers additional steric and electronic character to the carbonyl, which can influence reactivity in condensation and cross-coupling reactions. The aryl chloride at C-5 is generally less reactive than the aryl bromide toward oxidative addition, allowing for selective manipulation of each halogen under appropriate conditions.

Key Physical and Chemical Properties

As a solid aromatic ketone, 1-(2-Bromo-5-chlorophenyl)ethanone typically presents as a pale yellow to off-white crystalline powder at room temperature. The compound is expected to be sparingly soluble in water but readily soluble in common organic solvents such as dichloromethane, ethyl acetate, acetone, tetrahydrofuran, and dimethyl sulfoxide (DMSO).

The aryl ketone carbonyl stretching frequency appears in the infrared spectrum in the characteristic region for conjugated carbonyl groups (approximately 1670–1690 cm⁻¹). The two halogens and the acetyl group collectively deactivate the aromatic ring toward electrophilic aromatic substitution, while the aryl–halogen bonds facilitate metal-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Negishi, and Buchwald–Hartwig couplings.

Note: Specific melting point, boiling point, and density values should be confirmed against the certificate of analysis (CoA) supplied with the product lot.

Synthetic Applications and Research Uses

The presence of three distinct reactive functional groups makes 1-(2-Bromo-5-chlorophenyl)ethanone a valuable intermediate in multi-step organic synthesis. Common research applications include:

• Palladium-catalyzed cross-coupling: The aryl bromide at C-2 can undergo Suzuki–Miyaura, Negishi, or Stille coupling reactions to introduce aryl, vinyl, or alkyl groups, enabling rapid diversification of the carbon skeleton.
• Nucleophilic addition and condensation: The carbonyl group participates in Grignard additions, reductive aminations, and aldol-type condensations to yield secondary alcohols, amines, or extended carbon chains.
• Heterocycle synthesis: α-Haloketone chemistry and condensation with nitrogen or sulfur dinucleophiles (e.g., thiourea, guanidine, hydrazines) can afford heterocyclic scaffolds relevant to medicinal chemistry programs.
• Buchwald–Hartwig amination: Selective C–N bond formation at the aryl bromide position extends access to aniline-type pharmacophores.

Because the compound carries two different halogens with differing reactivity, sequential functionalization strategies are feasible, increasing its utility as a divergent building block.

Safe Handling, Storage, and Regulatory Considerations

As with most halogenated aromatic compounds, appropriate precautions should be observed when handling 1-(2-Bromo-5-chlorophenyl)ethanone:

• Personal protective equipment (PPE): Wear nitrile gloves, safety goggles, and a laboratory coat. Work in a well-ventilated fume hood to avoid inhalation of dust or vapors.
• Storage: Store in a tightly sealed container in a cool, dry, well-ventilated area, away from heat, open flames, and incompatible materials (strong oxidizers, strong bases). Recommended storage temperature is typically 2–8 °C or room temperature as indicated on the product label; consult the specific CoA and SDS for your lot.
• Waste disposal: Dispose of residues in accordance with local, regional, and national regulations governing halogenated organic waste.
• Safety data: Always consult the Safety Data Sheet (SDS) provided by Aladdin Scientific before use. Key hazard classifications (GHS) should be reviewed prior to working with this material.

Specific GHS hazard statements and precautionary statements should be verified on the current SDS for product B400833.

Ordering and Quality Information

1-(2-Bromo-5-chlorophenyl)ethanone is available from Aladdin Scientific under SKU B400833. When placing an order, consider the following:

• Purity: Check the current product page or request a Certificate of Analysis (CoA) to confirm purity grade and analytical data (e.g., GC purity, NMR confirmation) for your specific lot.
• Pack sizes: Multiple pack sizes may be available to suit both small-scale exploratory research and larger preparative needs. Contact Aladdin customer service for bulk quotations.
• Lead time and shipping: Shipping conditions (e.g., ambient, cool pack) and estimated lead times are confirmed at the time of order. Refer to Aladdin's shipping and delivery policy for international orders involving controlled or regulated chemicals.
• Returns and quality concerns: If you receive a product that does not meet specification, contact Aladdin Scientific customer service promptly with your order number and lot number. Refer to Aladdin's returns and refunds policy for eligibility criteria.

Frequently asked questions

What is the CAS number and molecular formula of 1-(2-Bromo-5-chlorophenyl)ethanone?

The CAS number is 1006-40-2. The molecular formula is C₈H₆BrClO, corresponding to a molecular weight of approximately 233.49 g/mol. It bears both an aryl bromide and an aryl chloride substituent on the acetophenone core.

In what solvents is 1-(2-Bromo-5-chlorophenyl)ethanone soluble?

The compound is expected to be sparingly soluble in water but readily soluble in common organic solvents including dichloromethane, ethyl acetate, acetone, tetrahydrofuran (THF), and dimethyl sulfoxide (DMSO). Always verify solubility for your specific application and lot.

Can I selectively react the aryl bromide without affecting the aryl chloride in this compound?

Yes, selective functionalization is generally feasible. Aryl bromides are significantly more reactive than aryl chlorides toward palladium-catalyzed cross-coupling reactions (e.g., Suzuki–Miyaura) under standard conditions, because oxidative addition of Pd(0) into the C–Br bond is kinetically and thermodynamically preferred over C–Cl. Careful optimization of catalyst, ligand, temperature, and base can achieve high selectivity for the C–Br bond, leaving the C–Cl intact for subsequent transformation.

How should 1-(2-Bromo-5-chlorophenyl)ethanone be stored to maintain stability?

Store the compound in a tightly sealed container in a cool, dry, and well-ventilated area, away from heat sources, open flames, strong oxidizers, and strong bases. The recommended storage temperature (room temperature or 2–8 °C) should be confirmed on the product label and the current SDS for SKU B400833. Protect from prolonged exposure to light and moisture.

What is the Aladdin Scientific SKU for 1-(2-Bromo-5-chlorophenyl)ethanone and how do I order it?

The product is listed under SKU B400833 on the Aladdin Scientific website. You can place an order directly through the product page, or contact Aladdin customer service for bulk pricing, custom pack sizes, or expedited shipping inquiries.

What safety precautions should I take when handling this compound in the laboratory?

Wear appropriate PPE including nitrile gloves, safety goggles, and a laboratory coat. Handle the compound in a well-ventilated fume hood to minimize inhalation of dust or vapors. Consult the Safety Data Sheet (SDS) for SKU B400833 before use for full GHS hazard classification, first-aid measures, and disposal guidance. Dispose of halogenated waste in accordance with applicable local regulations.

References

1. Aladdin Scientific product page for 1-(2-Bromo-5-chlorophenyl)ethanone, SKU B400833. Aladdin Scientific.
2. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed. Wiley-Interscience, 1992. (General reference for aryl halide reactivity and cross-coupling.)
3. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chemical Reviews 1995, 95 (7), 2457–2483. doi:10.1021/cr00039a007

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