2-Amino-3-Bromobenzoic Acid: Properties, Uses & Lab Guide

2-Amino-3-bromobenzoic acid is a bifunctional aromatic building block bearing both a free amino group and a carboxylic acid ortho to a bromine substituent, making it a versatile intermediate in pharmaceutical synthesis, heterocyclic chemistry, and medicinal chemistry research.

Chemical Name

2-Amino-3-bromobenzoic acid

CAS Number

5794-88-7

Molecular Formula

C₇H₆BrNO₂

Molecular Weight

216.03 g/mol

Functional Groups

Primary amine (–NH₂), carboxylic acid (–COOH), aryl bromide (C–Br)

Recommended Storage

Cool, dry place; protected from light and moisture

Primary Application

Pharmaceutical intermediate; heterocyclic and cross-coupling synthesis

Chemical Identity and Physical Properties

2-Amino-3-bromobenzoic acid (CAS 5794-88-7) is an ortho-substituted benzoic acid derivative with molecular formula C₇H₆BrNO₂ and molecular weight of approximately 216.03 g/mol. The compound features three distinct functional groups on the benzene ring: a primary amino group (–NH₂) at the 2-position, a bromine atom at the 3-position, and a carboxylic acid (–COOH) at the 1-position. This arrangement creates significant opportunities for intramolecular and intermolecular reactivity.

The compound typically appears as a solid powder, and its melting point and exact solubility data should be verified against the supplier's certificate of analysis (CoA). It shows moderate solubility in polar organic solvents such as methanol, ethanol, and dimethyl sulfoxide (DMSO), and limited solubility in water due to its aromatic character, though the carboxylic acid moiety does confer some hydrophilicity.

The ortho relationship between the amino and carboxyl groups is particularly noteworthy: under appropriate conditions, intramolecular cyclization can be facilitated, forming heterocyclic ring systems such as benzoxazoles or anthranilic acid-type scaffolds, which are of broad interest in drug discovery programs.

Synthesis Applications and Reactivity

The multifunctional nature of 2-amino-3-bromobenzoic acid makes it a highly sought-after building block in synthetic organic and medicinal chemistry. Its three reactive sites can be independently addressed under selective reaction conditions:

• Aryl bromide for cross-coupling reactions: The C–Br bond at the 3-position is well-suited for palladium-catalyzed cross-coupling reactions, including Suzuki–Miyaura, Buchwald–Hartwig, and Sonogashira couplings, enabling the introduction of diverse aryl, alkyl, or alkynyl substituents without disturbing the amino or carboxylic acid groups when appropriate protecting group strategies are employed.
• Amino group for amide bond formation and cyclization: The primary amine can participate in amide coupling reactions, condensation with carbonyl-containing partners, or intramolecular cyclization with the adjacent carboxylic acid to furnish benzazinone or isatoic anhydride-type scaffolds under suitable activation conditions.
• Carboxylic acid as a handle for esterification or amidation: Standard carbodiimide-mediated (EDC/DCC) or acid chloride activation methods allow functionalization of the carboxyl group for the synthesis of esters, amides, and peptidomimetics.

This compound is particularly valued as a precursor to anthranilic acid analogs and brominated isatin derivatives, both of which appear frequently in biologically active compound libraries and fragment-based drug discovery campaigns.

Handling, Safety, and Storage Guidelines

Although 2-amino-3-bromobenzoic acid is not classified as acutely toxic under standard GHS criteria (verify with the current Safety Data Sheet before use), researchers should apply standard laboratory safety protocols when handling aromatic amine compounds:

• Personal protective equipment (PPE): Wear appropriate chemical-resistant gloves (nitrile recommended), a laboratory coat, and safety goggles. If fine powder is generated during weighing, use a suitable dust mask or conduct operations in a fume hood.
• Inhalation and skin contact: Avoid breathing dust or aerosols. Wash hands and exposed skin thoroughly with soap and water after handling. Aromatic amines as a class warrant caution; refer to the product SDS for specific hazard classifications.
• Storage conditions: Store in a tightly sealed container in a cool (15–25 °C), dry location, protected from light and moisture. Prolonged exposure to air and humidity can lead to gradual oxidation of the amino group or hydrolysis of surface salts.
• Stability: The compound is generally stable under ambient conditions when properly stored. Avoid contact with strong oxidizers, strong acids, and strong bases, which may react with either the amine or carboxylate functionality.
• Disposal: Dispose of residues and contaminated materials in accordance with local chemical waste regulations.

Always consult the most current Safety Data Sheet (SDS) provided by Aladdin Scientific before beginning experimental work.

Quality Specifications and Purity Considerations

For research applications, the purity of 2-amino-3-bromobenzoic acid is a critical parameter that directly impacts reaction yields and reproducibility. Key quality attributes to verify upon receipt include:

• Purity by HPLC or GC: High-purity material (≥97–98% by HPLC) is recommended for sensitive synthetic transformations, especially palladium-catalyzed couplings where trace metal or organic impurities can poison the catalyst or skew analytical results.
• Identity confirmation: Verify the compound identity via melting point determination, ¹H NMR, and/or mass spectrometry against published or supplier-provided spectral data.
• Moisture content: The carboxylic acid and amino groups are both capable of forming hydrates or solvates. Karl Fischer titration or loss-on-drying (LOD) measurement should be considered for highly moisture-sensitive applications.
• Certificate of Analysis (CoA): Aladdin Scientific provides lot-specific CoA data; request the CoA matched to the specific lot number received to confirm all quality parameters.

For discovery chemistry, standard research-grade purity is typically sufficient. For regulatory or GMP-adjacent workflows, contact Aladdin Scientific's technical team to discuss available grades and documentation requirements.

Frequently asked questions

What is the CAS number for 2-Amino-3-bromobenzoic acid?

The CAS registry number for 2-Amino-3-bromobenzoic acid is 5794-88-7. This number can be used to confirm product identity when ordering or searching chemical databases.

What solvents are suitable for dissolving 2-Amino-3-bromobenzoic acid?

2-Amino-3-bromobenzoic acid is generally soluble in polar organic solvents such as DMSO, DMF, methanol, and ethanol. Its solubility in water is limited but may be enhanced under basic conditions by deprotonating the carboxylic acid. Always conduct a small-scale solubility test before preparing stock solutions.

Can 2-Amino-3-bromobenzoic acid be used in palladium-catalyzed cross-coupling reactions?

Yes, the aryl C–Br bond at the 3-position makes 2-Amino-3-bromobenzoic acid a viable substrate for palladium-catalyzed cross-coupling reactions such as Suzuki–Miyaura and Sonogashira couplings. Protecting group strategies for the amine and/or carboxylic acid may be required depending on the reaction conditions to avoid side reactions or catalyst poisoning.

How should 2-Amino-3-bromobenzoic acid be stored to maintain stability?

Store 2-Amino-3-bromobenzoic acid in a tightly sealed container at room temperature (15–25 °C), away from light, heat, and moisture. Avoid exposure to strong oxidizers or corrosive reagents. Under these conditions, the compound is expected to remain stable for an extended period; refer to the product CoA for specific shelf-life information.

What are the main synthetic uses of 2-Amino-3-bromobenzoic acid in medicinal chemistry?

In medicinal chemistry, 2-Amino-3-bromobenzoic acid serves as a versatile building block for constructing heterocyclic scaffolds such as benzazinones, quinazolinones, and benzoxazoles, as well as anthranilic acid analogs used in drug discovery. Its aryl bromide handle also enables diversification through cross-coupling chemistry to generate compound libraries.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. General reference for aromatic substitution and functional group transformations.
2. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chemical Reviews, 1995, 95(7), 2457–2483. doi:10.1021/cr00039a007
3. Aladdin Scientific Product Page: 2-Amino-3-bromobenzoic acid, SKU A123772. Aladdin Scientific (accessed 2024).

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