Industrial Purity Specifications for 3-Bromophthalic Anhydride (CAS 82-73-5)
- Standard industrial purity exceeds 98% with strict moisture control to prevent hydrolysis.
- Quality verified via HPLC and NMR to ensure consistent reaction yields in downstream synthesis.
- Available in bulk quantities with comprehensive COA documentation from a reliable global manufacturer.
In the realm of fine chemical synthesis and pharmaceutical intermediate production, 3-Bromophthalic anhydride serves as a critical building block. Known systematically as 4-bromo-2-benzofuran-1,3-dione, this compound (CAS 82-73-5) is essential for constructing complex organic frameworks, including protein degrader building blocks and specialized polymers. For process chemists and procurement managers, understanding the nuances of industrial purity specifications is vital to maintaining high reaction yields and minimizing downstream purification costs.
As a leading entity in the chemical sector, NINGBO INNO PHARMCHEM CO.,LTD. emphasizes the importance of rigorous quality control standards. Variations in purity levels, particularly regarding moisture content and residual bromine, can significantly alter the kinetics of nucleophilic attacks during amidation or esterification processes. This technical overview details the physical properties, analytical verification methods, and commercial considerations necessary for secure bulk procurement.
Standard Industrial Purity Criteria and Physical Properties
The market typically offers this anhydride in purity grades ranging from 95% to 99%. However, for large-scale manufacturing, a minimum assay of 98.0% is generally required to ensure process reliability. The presence of impurities, such as unreacted phthalic anhydride or dibrominated byproducts, can complicate crystallization steps later in the synthesis route. The physical characteristics of high-grade material are consistent and serve as a primary indicator of quality before advanced analytical testing.
The following table outlines the standard physical properties expected of premium grade 3-Bromophthalic anhydride:
| Property | Specification |
|---|---|
| CAS Number | 82-73-5 |
| Molecular Formula | C8H3BrO3 |
| Molecular Weight | 227.01 g/mol |
| Appearance | White to Off-White Crystalline Solid |
| Melting Point | 132-134℃ |
| Assay (Purity) | ≥ 98.0% (HPLC Area %) |
| Storage Condition | Under inert gas (Nitrogen/Argon) at 2-8°C |
Maintaining the integrity of the anhydride ring is crucial. Exposure to ambient humidity can lead to hydrolysis, forming 3-bromophthalic acid, which reduces reactivity in coupling reactions. Therefore, proper packaging under inert atmosphere is a non-negotiable aspect of the manufacturing process for high-quality intermediates.
Analytical Methods for Verifying Purity
To guarantee that the material meets the required specifications for sensitive organic transformations, multiple analytical techniques are employed. Relying on a single method may overlook specific impurities that could act as catalyst poisons or side-reaction initiators.
High-Performance Liquid Chromatography (HPLC)
HPLC is the primary method for determining the quantitative assay of the product. A robust quality control protocol will show a single dominant peak with an area percentage greater than 98%. Minor peaks corresponding to starting materials or over-brominated species should be quantified and kept below defined thresholds.
Nuclear Magnetic Resonance (NMR) Spectroscopy
1H NMR and 13C NMR provide structural confirmation. The aromatic proton signals are distinct due to the bromine substitution pattern. Discrepancies in integration values can indicate the presence of regio-isomers or hydrolyzed acid forms, which are critical defects in high-value synthesis.
Karl Fischer Titration
Given the hygroscopic nature of acid anhydrides, water content must be strictly monitored. Industrial specifications often demand water content below 0.5% to prevent premature ring opening during storage or transport.
Impact of Manufacturing Process on Quality
The quality of the final product is inherently linked to the efficiency of the synthesis route. The standard production method involves the bromination of phthalic anhydride. Control over the brominating agent, reaction temperature, and work-up procedures determines the level of residual impurities. Advanced facilities utilize continuous flow chemistry or optimized batch reactors to minimize heat spots that could lead to decomposition or poly-bromination.
When sourcing high-purity 4-Bromoisobenzofuran-1,3-dione, buyers should verify that the supplier employs rigorous post-reaction purification steps, such as recrystallization from suitable solvents, to achieve the desired crystal lattice and purity profile.
Commercial Considerations and Bulk Procurement
For industrial clients, pricing is often a function of purity, packaging, and volume. While laboratory-scale prices may appear high per gram, the bulk price for kilogram or ton quantities drops significantly due to economies of scale in the manufacturing process. However, purchasing solely based on the lowest cost can be risky if the COA (Certificate of Analysis) does not provide detailed impurity profiles.
Key factors influencing commercial value include:
- Lead Time: Reliable supply chains ensure consistent production schedules.
- Packaging: Double-lined bags or sealed drums with nitrogen flushing are standard for moisture-sensitive materials.
- Documentation: Full traceability including MSDS, COA, and stability data.
Partnering with a global manufacturer like NINGBO INNO PHARMCHEM CO.,LTD. ensures access to material that meets international regulatory standards. This reduces the risk of batch failure during critical scale-up phases. Consistency in supply allows process chemists to lock in reaction parameters without needing to re-validate protocols for every new shipment.
Safety and Handling Protocols
Safety data indicates that this compound carries specific hazards that must be managed during handling. It is classified with GHS symbols indicating potential health irritation and flammability risks. The substance may cause skin irritation (H315) and serious eye irritation (H319). Furthermore, as an organic anhydride, it reacts vigorously with water and strong bases.
Personnel should utilize appropriate personal protective equipment (PPE), including chemical-resistant gloves and safety goggles. Storage areas must be cool, dry, and well-ventilated, strictly adhering to the recommended temperature range of 2-8°C for long-term stability. In the event of a fire, standard dry chemical or CO2 extinguishers should be used, as water may exacerbate the reaction due to the formation of corrosive acids.
Conclusion
Securing a reliable supply of 3-Bromophthalic anhydride with verified industrial purity is fundamental to the success of complex organic synthesis projects. By prioritizing suppliers who offer transparent analytical data, robust packaging, and consistent bulk price structures, manufacturers can mitigate risk and optimize production efficiency. Whether for pharmaceutical intermediates or advanced material science, the quality of this building block dictates the quality of the final output.