2-(2-Bromophenoxy)acetic Acid: Properties & Lab Uses

2-(2-Bromophenoxy)acetic Acid is a halogenated aryloxy acetic acid widely employed as a versatile building block in organic synthesis and pharmaceutical intermediate research.

Chemical Name

2-(2-Bromophenoxy)acetic Acid

CAS Number

1503-48-6

Molecular Formula

C₈H₇BrO₃

Molecular Weight

231.04 g/mol

Functional Groups

Aryl bromide, ether linkage, carboxylic acid

Primary Use

Synthetic building block and pharmaceutical intermediate

Chemical Structure and Key Properties

2-(2-Bromophenoxy)acetic Acid (CAS 1503-48-6) belongs to the class of phenoxyacetic acids in which a bromine atom is positioned ortho on the phenyl ring. Its molecular formula is C₈H₇BrO₃ with a molecular weight of approximately 231.04 g/mol. The molecule contains three distinct functional groups: an aryl bromide, an aryl ether oxygen bridge, and a terminal carboxylic acid group. This combination confers significant synthetic versatility, allowing the compound to participate in cross-coupling reactions via the C–Br bond, esterification and amidation via the carboxylic acid, and nucleophilic or electrophilic transformations at the aromatic ring.

The ortho substitution pattern of the bromine relative to the ether oxygen creates a sterically defined environment that can influence reactivity and selectivity in downstream transformations, making this compound particularly valuable in the design of chiral or conformationally constrained molecules.

Synthesis and Preparation Methods

2-(2-Bromophenoxy)acetic Acid is typically prepared by the O-alkylation of 2-bromophenol with a suitable haloacetic acid equivalent under basic conditions. A classical route involves reacting 2-bromophenol with chloroacetic acid or sodium chloroacetate in the presence of a base such as sodium hydroxide or potassium carbonate in aqueous or mixed aqueous-organic solvent systems. The phenoxide anion generated in situ attacks the electrophilic carbon of the chloroacetate, affording the aryloxy acetic acid product after acidification of the reaction mixture.

This Williamson ether synthesis approach is scalable and operationally straightforward, making the compound accessible for multigram synthesis in research and process chemistry settings. Purity of the final product is generally confirmed by HPLC, melting point determination, and spectroscopic characterization including ¹H NMR and ¹³C NMR.

Research and Pharmaceutical Applications

The compound's bifunctional nature—combining a reactive aryl halide with a carboxylic acid—makes it a high-value building block in medicinal chemistry and drug discovery. The aryl bromide moiety is well-suited for palladium-catalyzed cross-coupling reactions such as Suzuki–Miyaura, Sonogashira, and Buchwald–Hartwig couplings, enabling rapid structural diversification of lead compounds.

The acetic acid arm can be converted to esters, amides, hydroxamic acids, or heterocyclic ring systems, broadening the structural space accessible from a single starting material. Compounds within the phenoxyacetic acid class have historical precedent as herbicides, thyroid hormone analogs, and anti-inflammatory scaffolds, suggesting that derivatives of 2-(2-Bromophenoxy)acetic Acid may find utility in the exploration of similar biological targets. Additionally, the compound may serve as an intermediate in the synthesis of more complex molecules featuring benzofuranone or benzodioxole ring systems formed by intramolecular cyclization.

Handling, Storage, and Safety Considerations

As with other halogenated organic acids, 2-(2-Bromophenoxy)acetic Acid should be handled with appropriate personal protective equipment, including chemical-resistant gloves, safety goggles, and a laboratory coat. Work should be conducted in a well-ventilated area or fume hood to avoid inhalation of dust or aerosols. The compound should be stored in a cool, dry location away from incompatible materials such as strong bases and oxidizing agents.

Researchers should consult the Safety Data Sheet (SDS) supplied by Aladdin Scientific prior to use for detailed hazard classification, first-aid measures, and disposal guidance. Waste containing this compound should be disposed of in accordance with local and institutional regulations governing halogenated organic waste.

Frequently asked questions

What cross-coupling reactions is 2-(2-Bromophenoxy)acetic Acid suitable for?

The aryl bromide functionality makes this compound compatible with a range of palladium-catalyzed cross-coupling reactions, including Suzuki–Miyaura (with boronic acids), Sonogashira (with terminal alkynes), and Buchwald–Hartwig (with amines) couplings. These reactions enable efficient introduction of diverse substituents onto the aromatic ring for medicinal chemistry applications.

How should 2-(2-Bromophenoxy)acetic Acid be stored to maintain stability?

The compound should be stored in a tightly sealed container in a cool, dry, and well-ventilated area, protected from moisture and direct light. Keeping it away from strong oxidizing agents and bases will help prevent degradation of both the aryl bromide and carboxylic acid functionalities. Always refer to the Aladdin Scientific SDS for specific storage temperature recommendations.

Can 2-(2-Bromophenoxy)acetic Acid be used to synthesize benzofuranone derivatives?

Yes, 2-(2-Bromophenoxy)acetic Acid is a recognized precursor for benzofuran-2(3H)-one (2-coumaranone) synthesis via intramolecular cyclization strategies. Under appropriate reaction conditions such as metal-catalyzed intramolecular C–H or C–X functionalization, the aryl bromide and the acetic acid tether can be engaged to form the five-membered lactone ring system characteristic of benzofuranones.

What is the molecular weight and formula of 2-(2-Bromophenoxy)acetic Acid?

2-(2-Bromophenoxy)acetic Acid has the molecular formula C₈H₇BrO₃ and a molecular weight of approximately 231.04 g/mol. These values are useful for stoichiometric calculations in synthetic procedures.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (Williamson ether synthesis, general aryloxy acetic acid preparation)
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007
3. Buchwald, S. L.; Mauger, C.; Mignani, G.; Scholz, U. Industrial-Scale Palladium-Catalyzed Coupling of Aryl Halides and Amines — A Personal Account. Adv. Synth. Catal. 2006, 348, 23–39.

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