3-Bromo-2-nitroaniline: Handling, Storage & Lab Protocol

3-Bromo-2-nitroaniline is a halogenated aromatic amine intermediate widely used in organic synthesis, serving as a versatile building block for pharmaceuticals, agrochemicals, and dye chemistry.

CAS Number

59255-93-5

Molecular Formula

C₆H₅BrN₂O₂

Molecular Weight

217.02 g/mol

Appearance

Yellow to orange crystalline solid

Storage Conditions

Cool, dry, dark place; sealed container; away from oxidizers

SKU

B133567

Materials and Equipment Required

Before beginning any procedure with 3-Bromo-2-nitroaniline (Aladdin SKU: B133567), ensure all the following items are assembled:

• Personal Protective Equipment (PPE): Chemical-resistant nitrile gloves, safety goggles or a face shield, and a laboratory coat. A half-face respirator with organic-vapor cartridges is recommended when handling bulk quantities or generating dust.
• Ventilation: All weighing and dissolution steps must be performed inside a certified chemical fume hood.
• Weighing equipment: Analytical balance (±0.1 mg precision), calibrated anti-static weighing boats or spatulas.
• Solvents: Suitable organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), ethanol, or acetone (see dissolution protocol below). 3-Bromo-2-nitroaniline has limited solubility in water.
• Glassware: Amber glass vials or amber borosilicate flasks with PTFE-lined caps for stock solution preparation and storage.
• Waste disposal containers: Labeled halogenated organic-waste container compliant with local regulations.

Step-by-Step Handling and Dissolution Protocol

Follow these steps carefully to ensure reproducible results and personnel safety:

1. Don all PPE before opening the reagent container. Confirm the fume hood sash is at the appropriate working height and airflow is verified.
2. Equilibrate to room temperature: If the compound has been stored at low temperature, allow the sealed container to warm to ambient temperature (15–25 °C) before opening to prevent condensation on the solid.
3. Tare and weigh: Place a pre-tared weighing boat on the analytical balance. Transfer the required amount of 3-Bromo-2-nitroaniline using a clean, dry stainless-steel spatula. Minimize exposure time to atmosphere.
4. Dissolve the compound:
   • For DMSO or DMF stock solutions (recommended for biological assays): add the weighed solid to a clean amber vial, then add solvent incrementally with gentle swirling or vortex mixing. Typical stock concentrations of 10–100 mM are achievable. Gentle warming (≤40 °C) in a water bath may assist dissolution if needed.
   • For synthetic applications in ethanol or acetone: dissolve with magnetic stirring at room temperature in the fume hood.
5. Verify complete dissolution visually; the solution should appear clear yellow to amber. If particulates persist, filter through a 0.22 µm PTFE syringe filter.
6. Label all vessels with compound name, CAS number, concentration, solvent, date of preparation, and preparer's initials.
7. Seal containers promptly and return unused solid to the original amber container; reseal with Parafilm if appropriate and store under recommended conditions.

Note: Avoid prolonged exposure to strong light as nitroaniline derivatives can be light-sensitive.

Storage Recommendations

Proper storage of 3-Bromo-2-nitroaniline is critical to maintaining purity and reactivity over time:

• Temperature: Store at room temperature (15–25 °C) in a cool, dry location. Refrigeration (2–8 °C) may be employed for long-term storage; allow equilibration to room temperature before opening as noted above.
• Light: Store in amber glass containers or in the dark. Nitroaromatic compounds can undergo photodegradation upon prolonged UV or visible-light exposure.
• Moisture: Keep the container tightly sealed to prevent moisture absorption. Use desiccants (e.g., silica gel pouches) in storage areas with high humidity.
• Incompatibilities: Keep away from strong oxidizing agents, strong acids, strong bases, and open flames or heat sources. Aromatic amines can react vigorously with oxidizers.
• Shelf life: When stored correctly in the original sealed container, the compound is expected to remain stable. Periodic re-verification of purity by TLC or HPLC is recommended for critical applications.
• Stock solutions: DMSO or DMF stock solutions should be stored in tightly sealed amber vials at –20 °C and used within 3 months for optimal stability. Avoid repeated freeze-thaw cycles.

Safety and Waste Disposal

3-Bromo-2-nitroaniline is a chemical reagent with associated hazards that must be managed responsibly:

• Toxicity: As a nitroaromatic amine, this compound may be harmful if swallowed, inhaled, or absorbed through the skin. Aromatic amines as a class are associated with potential mutagenic and carcinogenic risk; handle with appropriate caution pending full hazard characterization for this specific compound.
• Skin and eye contact: Rinse immediately with copious water for at least 15 minutes in the event of skin or eye contact. Seek medical attention if irritation persists.
• Inhalation: Move to fresh air immediately if vapors or dust are inhaled. Seek medical attention if symptoms develop.
• Spill management: Contain solid spills with inert absorbent material (e.g., vermiculite or dry sand). Avoid generating dust. Transfer waste to a labeled halogenated-waste container. Clean the area with water, followed by appropriate solvent wipe-down in the fume hood.
• Waste disposal: All waste material, including contaminated gloves, paper towels, and solvent rinses, must be disposed of as halogenated organic chemical waste in accordance with local, regional, and national environmental regulations. Do NOT pour down the drain.
• Emergency: Consult the Safety Data Sheet (SDS) for B133567 available from Aladdin Scientific for complete hazard information and emergency procedures.

Frequently asked questions

What solvents are recommended for dissolving 3-Bromo-2-nitroaniline?

3-Bromo-2-nitroaniline dissolves well in polar aprotic solvents such as DMSO and DMF, and also in common organic solvents including ethanol and acetone. It has limited solubility in water. For biological screening assays, DMSO stock solutions are most commonly used. Gentle warming (up to 40 °C) can aid dissolution if needed.

How should I store 3-Bromo-2-nitroaniline stock solutions to maintain stability?

Stock solutions prepared in DMSO or DMF should be aliquoted into amber glass vials, tightly sealed, and stored at –20 °C. Under these conditions, solutions should remain stable for up to approximately 3 months; avoid repeated freeze-thaw cycles as these can degrade solution integrity. Always allow vials to reach room temperature before opening to prevent condensation.

Is 3-Bromo-2-nitroaniline stable at room temperature?

As a solid, 3-Bromo-2-nitroaniline is stable when stored at room temperature in a cool, dry, and dark location in a tightly sealed amber container. Like other nitroaromatic compounds, it may be susceptible to photodegradation upon prolonged exposure to light, so light exclusion is important. For extended storage, refrigeration at 2–8 °C is advisable.

What personal protective equipment (PPE) is required when working with 3-Bromo-2-nitroaniline?

At minimum, chemical-resistant nitrile gloves, safety goggles or a face shield, and a laboratory coat should be worn at all times. All handling should take place inside a certified chemical fume hood. When handling bulk quantities or when dust generation is likely, a half-face respirator fitted with organic-vapor and particulate cartridges is recommended. Consult the product SDS for full PPE guidance.

What are the main synthetic applications of 3-Bromo-2-nitroaniline?

3-Bromo-2-nitroaniline serves as a versatile intermediate in organic synthesis. The bromo substituent enables palladium-catalyzed cross-coupling reactions (e.g., Suzuki, Buchwald-Hartwig), while the ortho nitro and amino groups provide handles for cyclization reactions to form heterocyclic scaffolds such as benzimidazoles, indazoles, and related structures relevant to pharmaceutical and agrochemical research.

References

1. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (General reference for aromatic amine and nitroaromatic chemistry.)
2. Aladdin Scientific. Safety Data Sheet: 3-Bromo-2-nitroaniline, SKU B133567. (Consult current SDS for authoritative hazard and handling information.)
3. Joule, J. A.; Mills, K. Heterocyclic Chemistry, 5th ed.; Wiley-Blackwell: Chichester, 2010. (Reference for cyclization reactions of ortho-halonitroanilines to benzimidazoles and related heterocycles.)

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