3-Bromobenzoic acid (585-76-2) Physical and Chemical Properties
3-Bromobenzoic acid
Aromatic carboxylic acid bearing a meta‑bromo substituent, commonly used as a synthetic intermediate and building block in specialty chemical and pharmaceutical development.
| CAS Number | 585-76-2 |
| Family | Benzoic acid derivatives |
| Typical Form | Off-white crystalline powder |
| Common Grades | EP, JP |
3-Bromobenzoic acid is an aromatic monocarboxylic acid in the benzoic acid derivative class bearing a single bromo substituent at the meta (3-) position. Structurally it comprises a substituted benzene ring with a carboxyl group and a bromine atom in a 1,3-relationship; the electronic structure is characterized by conjugation between the aromatic π-system and the carboxylate/acid functionality, and by the inductive and weak resonance effects of the bromine substituent. The carboxylic acid confers the typical weak acidity and ability to form hydrogen bonds, whereas the bromine increases molecular mass, polarizability and lipophilicity relative to unsubstituted benzoic acid.
In terms of physicochemical behavior, the compound is a neutral, non-ionic solid at ambient conditions with limited water solubility relative to benzoic acid due to the hydrophobic influence of the bromo substituent. Acid–base chemistry is dominated by the carboxyl function (typical aromatic carboxylic acid behavior: deprotonation in basic media to the corresponding benzoate), and it participates in common organic transformations of carboxylic acids (esterification, formation of acid chlorides) and in reactions that exploit the aryl–halide bond (cross-coupling, nucleophilic aromatic substitution under forcing conditions). Thermally and chemically it behaves as a typical halogenated benzoic acid: generally stable as a crystalline solid but reactive under strong reducing, strongly nucleophilic, or strongly basic conditions that can displace or reductively remove the halogen or decarboxylate the ring system.
Common commercial grades reported for this substance include: EP, JP.
Basic Physical Properties
Density
No experimentally established value for this property is available in the current data context.
Melting Point
No experimentally established value for this property is available in the current data context.
Boiling Point
No experimentally established value for this property is available in the current data context.
Vapor Pressure
No experimentally established value for this property is available in the current data context.
Flash Point
No experimentally established value for this property is available in the current data context.
Chemical Properties
Solubility and Phase Behavior
3-Bromobenzoic acid is reported as an off-white crystalline powder. As a substituted benzoic acid it is expected to have limited aqueous solubility in its protonated form but to become significantly more water-soluble upon neutralization to the benzoate anion. Solubility in organic solvents is typically higher: polar aprotic and mid-polarity organic solvents dissolve aromatic carboxylic acids readily. The meta-bromo substituent increases hydrophobic surface area and polarizability relative to benzoic acid, reducing aqueous solubility and increasing affinity for nonpolar phases; this is consistent with the computed partitioning descriptor discussed below.
Reactivity and Stability
The carboxylic acid group is the primary reactive handle for classical transformations (esterification, amidation after activation, conversion to acid chloride). The aryl–bromide bond is a synthetically useful functional group for carbon–carbon and carbon–heteroatom bond-forming reactions (cross-coupling type transformations) and can be displaced under strongly nucleophilic or metal-catalyzed conditions. The aromatic ring bearing a carboxyl group is overall deactivating toward electrophilic aromatic substitution; the bromine at the meta position also exerts a mild deactivating inductive effect and is meta-directing for electrophilic substitutions. Under strongly reducing conditions the bromine may be reductively removed; decarboxylation may occur at elevated temperatures or under catalytic conditions designed to remove carboxyl groups. As a solid, the substance is chemically stable under normal storage but should be kept away from strong oxidizing agents and strong bases that may promote undesired side reactions.
Thermodynamic Data
Standard Enthalpies and Heat Capacity
No experimentally established value for this property is available in the current data context.
Molecular Parameters
Molecular Weight and Formula
- Molecular formula: \(\ce{C7H5BrO2}\)
- Molecular weight: 201.02
- Exact mass / Monoisotopic mass: 199.94729
These values reflect a seven-carbon aromatic scaffold substituted by one bromine and a carboxyl unit; the heavy-atom count is reported as 10.
LogP and Polarity
- XLogP3 (computed): 2.9
- Topological Polar Surface Area (TPSA): 37.3
- Hydrogen bond donor count: 1
- Hydrogen bond acceptor count: 2
The computed \(\log P\) indicates moderate lipophilicity consistent with reduced aqueous solubility and increased partitioning into organic phases. TPSA and the H-bond counts are consistent with a single hydrogen-bond-donating carboxylic acid and two acceptor atoms (carbonyl and hydroxyl oxygen) capable of solvation and intermolecular hydrogen bonding.
Structural Features
- SMILES:
C1=CC(=CC(=C1)Br)C(=O)O - InChI:
InChI=1S/C7H5BrO2/c8-6-3-1-2-5(4-6)7(9)10/h1-4H,(H,9,10) - InChIKey:
VOIZNVUXCQLQHS-UHFFFAOYSA-N - Rotatable bond count (computed): 1
- Molecular complexity (computed): 136
- Formal charge: 0
Structurally the compound is a single covalently bonded unit with no stereocenters. The carboxyl group provides a planar conjugated moiety attached to the aromatic ring; the bromine atom increases polarizability and can participate indirectly in noncovalent interactions via halogen bonding motifs in solid-state packing.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS number: 585-76-2
- EC number: 209-562-3
- UNII: 7DCT3A73LX
- ChEBI: CHEBI:166850
- ChEMBL: CHEMBL63399
- DSSTox Substance ID: DTXSID8060408
Also associated identifiers appearing in supplier and registry lists include several legacy and internal accession numbers.
Synonyms and Structural Names
Common synonyms and name variants include: m-bromobenzoic acid; Benzoic acid, 3-bromo-; 3-bromobenzenecarboxylic acid; meta-bromobenzoic acid. Multiple depositor-supplied synonyms and catalog identifiers exist reflecting various naming conventions and legacy records.
Industrial and Commercial Applications
Representative Uses and Industry Sectors
3-Bromobenzoic acid is primarily used as an intermediate in organic synthesis. Its role is typical for halogenated aromatic carboxylic acids: as a building block for the preparation of more complex molecules in pharmaceutical, agrochemical and specialty-chemical research and for derivatization to esters, amides or acid derivatives. It is also encountered in materials and fine-chemical manufacturing where halogenated benzoic motifs are required.
Role in Synthesis or Formulations
In synthetic applications the carboxyl group is used for activation and coupling chemistry, while the aryl bromide is a handle for metal-mediated or nucleophilic substitution strategies to introduce diverse substituents on the aromatic ring. Typical transformations include esterification, amidation (after activation), formation of acid chlorides, and the use of the aryl–halide bond in forming C–C and C–heteroatom bonds. No concise application summary is available in the current data context; in practice this substance is selected based on its general properties described above.
Safety and Handling Overview
Acute and Occupational Toxicity
GHS-based hazard information reported for commercial material formulations indicates skin and eye irritation and potential for respiratory tract irritation. Reported hazard statements include: H315 — Causes skin irritation; H319 — Causes serious eye irritation; H335 — May cause respiratory irritation. The GHS signal word reported is "Warning." These classifications indicate the need to avoid skin and eye contact and to minimize inhalation exposure during handling.
Storage and Handling Considerations
Handle in a well-ventilated area with appropriate personal protective equipment (gloves, eye protection, protective clothing) to prevent skin and eye contact and minimize dust generation. Store in a cool, dry, well-sealed container away from incompatible materials (strong oxidizers, strong reducers). Spill and waste handling should follow local regulations and standard procedures for halogenated organic solids. For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
