1-(Bromomethyl)naphthalene: Properties, Uses & Handling FAQ
1-(Bromomethyl)naphthalene: Properties, Uses & Handling FAQ
1-(Bromomethyl)naphthalene is a reactive benzylic organobromine compound widely employed in organic synthesis as an alkylating and benzylation reagent for the introduction of the 1-naphthylmethyl group onto nucleophilic substrates.
- CAS Number
- 3163-27-7
- Molecular Formula
- C₁₁H₉Br
- Molecular Weight
- 221.10 g/mol
- Appearance
- Colorless to pale yellow liquid or low-melting solid
- Functional Class
- Benzylic alkyl bromide / benzylation reagent
- Recommended Storage
- Cool, dark, dry place; store under inert atmosphere
Chemical Identity and Structure
1-(Bromomethyl)naphthalene (CAS 3163-27-7, molecular formula C₁₁H₉Br, MW 221.10 g/mol) consists of a naphthalene ring system bearing a –CH₂Br substituent at the 1-position. The benzylic carbon is activated by the adjacent aromatic system, making the C–Br bond highly susceptible to nucleophilic displacement (SN2) and, to a lesser extent, solvolysis (SN1). This electronic activation is analogous to that observed in benzyl bromide but is further modulated by the extended π-conjugation of the naphthalene scaffold, influencing both reactivity and spectroscopic properties.
The compound is typically obtained as a colorless to pale-yellow liquid or low-melting solid and has a characteristic aromatic odor. Its 1-naphthyl regiochemistry distinguishes it from the 2-(bromomethyl)naphthalene isomer, offering different steric environments useful for stereoselective and structure–activity relationship studies.
Synthetic Applications
1-(Bromomethyl)naphthalene serves as a versatile electrophilic building block across multiple synthetic contexts:
- O-Alkylation: Reacts with alcohols and phenols (in the presence of base) to form naphthylmethyl ethers, which are employed as protecting groups for hydroxyl functionalities due to their stability under a range of conditions and ease of removal by hydrogenolysis or Lewis-acid-mediated cleavage.
- N-Alkylation: Amines and nitrogen heterocycles undergo efficient N-benzylation, allowing quaternary ammonium salt formation or N-protected amine synthesis.
- C-Alkylation: Stabilized carbanions (malonates, β-ketoesters, enolates) react via SN2 to introduce the 1-naphthylmethyl group at carbon.
- S-Alkylation: Thiols and thiolates are alkylated to afford thioethers relevant in medicinal chemistry and materials research.
- Pharmaceutical and Material Science Intermediates: The naphthylmethyl motif appears in bioactive molecules and liquid-crystal precursors, making this bromide a key intermediate in target synthesis.
Handling, Safety, and Storage
Hazard Profile: As a reactive benzylic bromide, 1-(Bromomethyl)naphthalene is a lachrymator and a potential alkylating agent. It should be treated as a tissue irritant (skin, eyes, and respiratory tract). Prolonged or repeated exposure should be avoided. Consult the current Safety Data Sheet (SDS) for the authoritative hazard classification, GHS pictograms, and exposure limits before use.
Personal Protective Equipment (PPE): Use chemical-resistant gloves (e.g., nitrile), safety goggles or a face shield, and a laboratory coat. Handle in a well-ventilated fume hood at all times.
Storage: Store in a tightly sealed container in a cool (2–8 °C recommended), dark, and dry location. An inert atmosphere (nitrogen or argon) is advised to minimize hydrolysis and oxidative degradation. Segregate from bases, oxidizing agents, and moisture-sensitive materials.
Disposal: Dispose of waste in accordance with local and institutional regulations for halogenated organic compounds. Do not pour down the drain.
Purity, Quality, and Analytical Characterization
Research-grade 1-(Bromomethyl)naphthalene from Aladdin Scientific (SKU B152874) is supplied at high purity suitable for synthetic applications. Researchers should verify purity specifications on the product page or Certificate of Analysis (CoA), as lot-to-lot purity data is available upon request.
Recommended analytical methods:
- GC or GC-MS: Primary method for purity determination and identification of volatile impurities.
- ¹H NMR: Characteristic signals include the –CH₂Br methylene protons (typically ~δ 4.8–5.0 ppm) and aromatic protons of the naphthalene system (δ 7.4–8.2 ppm).
- TLC: Useful for rapid in-process monitoring; visualized under UV (254 nm).
- Elemental Analysis / HRMS: For confirmation of molecular formula when required.
Color change from colorless to deep yellow or brown indicates decomposition; such material should not be used without re-purification.
Ordering and Availability
1-(Bromomethyl)naphthalene is available from Aladdin Scientific under SKU B152874. To place an order or request a quotation, visit the Aladdin Scientific website or contact your regional sales representative. Bulk quantities and custom packaging may be available; please inquire directly with our sales team. A Certificate of Analysis (CoA) and Safety Data Sheet (SDS) are available for download on the product page or on request.
For questions regarding stock availability, lead times, or pricing, please contact Aladdin Scientific customer service. Volume discounts and institutional procurement agreements are available for qualifying organizations.
Frequently asked questions
What is 1-(Bromomethyl)naphthalene used for in organic synthesis?
1-(Bromomethyl)naphthalene is primarily used as an electrophilic alkylating agent to introduce the 1-naphthylmethyl group onto nucleophiles including alcohols (O-alkylation), amines (N-alkylation), stabilized carbanions (C-alkylation), and thiols (S-alkylation). It also serves as a protecting-group precursor and as an intermediate in pharmaceutical and materials synthesis.
How should 1-(Bromomethyl)naphthalene be stored to prevent degradation?
Store 1-(Bromomethyl)naphthalene in a tightly sealed container at 2–8 °C in a cool, dark, and dry environment, preferably under an inert atmosphere of nitrogen or argon. Moisture and light accelerate hydrolysis and discoloration. Discard or re-purify any material that has turned yellow-brown, as this indicates decomposition.
Is 1-(Bromomethyl)naphthalene the same as 1-naphthylmethyl bromide?
Yes, 1-(Bromomethyl)naphthalene and 1-naphthylmethyl bromide are synonymous names for the same compound (CAS 3163-27-7). Other equivalent names include α-bromonaphthalene methyl or 1-naphthalenemethyl bromide. Always verify by CAS number when ordering to avoid confusion with the 2-substituted isomer.
What safety precautions are required when handling 1-(Bromomethyl)naphthalene?
As a lachrymator and reactive alkylating agent, 1-(Bromomethyl)naphthalene must be handled exclusively in a fume hood wearing nitrile gloves, safety goggles, and a lab coat. Avoid inhalation, skin contact, and eye contact. Consult the current SDS for detailed first-aid measures, spill procedures, and waste disposal requirements.
How can I confirm the purity of the 1-(Bromomethyl)naphthalene I received?
Request the Certificate of Analysis (CoA) for your specific lot from Aladdin Scientific's product page or customer service. You can independently verify purity by GC or GC-MS, and confirm identity by ¹H NMR, looking for the characteristic –CH₂Br methylene signal near δ 4.8–5.0 ppm and the naphthalene aromatic protons at δ 7.4–8.2 ppm.
What is the difference between 1-(Bromomethyl)naphthalene and 2-(Bromomethyl)naphthalene?
The two compounds are regioisomers differing in the position of the –CH₂Br group on the naphthalene ring: position 1 (peri environment, more sterically hindered) versus position 2. This difference in steric and electronic environment can affect reaction rates, selectivity, and the biological or physical properties of products derived from each isomer. Always confirm the desired regioisomer by CAS number before ordering.
References
- March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General reference for benzylic halide reactivity and alkylation reactions.)
- Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Textbook reference for SN2 reactivity of activated alkyl halides.)
- Aladdin Scientific. Product page: 1-(Bromomethyl)naphthalene, SKU B152874. Certificate of Analysis available upon request.
Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.
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