2-Amino-4-(4-bromophenyl)thiazole: Handling & Use Protocol

2-Amino-4-(4-bromophenyl)thiazole is a brominated 2-aminothiazole building block widely employed as a versatile synthetic intermediate in medicinal chemistry, heterocyclic synthesis, and the preparation of pharmacologically active scaffolds.

Product Name

2-Amino-4-(4-bromophenyl)thiazole

SKU

A140256

Molecular Formula

C9H7BrN2S

Molecular Weight

255.13 g/mol

CAS Number

13181-17-4

Recommended Storage

Cool, dry place; protect from light and moisture

Typical Solubility

Soluble in DMSO and DMF; sparingly soluble in ethanol; poorly soluble in water

Safety and Pre-Experimental Precautions

Before working with 2-Amino-4-(4-bromophenyl)thiazole (A140256), review the current Safety Data Sheet (SDS) available from Aladdin Scientific. The compound contains an aryl bromide moiety and a primary amine group; although it is not classified among highly acutely toxic reagents, standard laboratory precautions apply.

• Personal Protective Equipment (PPE): Wear nitrile gloves, a lab coat, and safety goggles at all times during handling.
• Ventilation: Handle in a well-ventilated fume hood to avoid inhalation of fine dust or aerosols.
• Skin and Eye Contact: In case of skin contact, wash immediately with soap and water for at least 15 minutes. For eye contact, rinse with copious water and seek medical attention.
• Waste Disposal: Dispose of all waste according to local institutional and regulatory guidelines for halogenated organic compounds.

Confirm the identity and purity of the compound by checking the certificate of analysis (CoA) supplied with the product before use.

Stock Solution Preparation and Dissolution

2-Amino-4-(4-bromophenyl)thiazole has limited aqueous solubility. For most biochemical and pharmacological assays, prepare a concentrated stock solution in an organic solvent before aqueous dilution.

Recommended Solvents and Concentrations

1. DMSO (Dimethyl Sulfoxide) — Preferred: Dissolve the compound at 10–50 mM in anhydrous DMSO. Briefly vortex, then sonicate (30–60 s) in an ultrasonic bath if needed to achieve complete dissolution. DMSO stocks are stable at –20 °C for up to 6 months when stored in sealed, desiccated vials.
2. DMF (N,N-Dimethylformamide): Suitable for synthetic applications. Prepare at 50–100 mM. DMF is not recommended for cell-based assays due to cytotoxicity at higher concentrations.
3. Ethanol: Limited solubility; use only at concentrations ≤5 mM. Warm gently (37 °C water bath) if needed.

Working Solution Preparation

Dilute stock solutions into aqueous buffer or cell culture medium immediately before use, keeping the final organic solvent content ≤0.1% (v/v) for cell-based work to minimize solvent effects. Prepare fresh working solutions each day; avoid repeated freeze–thaw cycles of the stock by aliquoting into single-use volumes before freezing.

Typical Synthetic Applications

2-Amino-4-(4-bromophenyl)thiazole serves as a multifunctional building block in heterocyclic and medicinal chemistry owing to its reactive 2-amino group and the aryl bromide handle on the pendant phenyl ring.

1. Acylation and Amide Bond Formation

The primary amine at the 2-position reacts readily with acyl chlorides or anhydrides under mild conditions (0 °C to room temperature, anhydrous DCM or THF, base such as Et3N or DIPEA) to afford 2-acylaminothiazole derivatives. Monitor reaction progress by TLC (silica gel; ethyl acetate/hexane eluent systems).

2. Palladium-Catalyzed Cross-Coupling via the Aryl Bromide

The 4-bromophenyl substituent undergoes standard Pd-catalyzed reactions, including:

• Suzuki–Miyaura coupling: React with arylboronic acids using Pd(PPh3)4 or Pd(dppf)Cl2 as catalyst, K2CO3 as base, in DMF/H2O or dioxane/H2O at 80–100 °C under inert atmosphere.
• Buchwald–Hartwig amination: Introduce diverse amine functionalities using Pd2(dba)3/XPhos catalyst systems.
• Sonogashira coupling: Couple with terminal alkynes using Pd/Cu co-catalysis in the presence of an amine base.

3. Condensation Reactions

The 2-amino group participates in condensation with aldehydes, ketones, and 1,3-dicarbonyl compounds to form Schiff bases, dihydropyrimidines, and related fused heterocycles relevant to medicinal chemistry programs.

General Note: All reactions should be conducted under appropriate conditions confirmed by literature precedent. Reaction yields and conditions may vary; optimization is recommended for new substrate combinations.

Storage and Stability Guidelines

Proper storage is essential to maintain the integrity of 2-Amino-4-(4-bromophenyl)thiazole over time.

• Recommended Temperature: Store at room temperature (15–25 °C) or at 2–8 °C in a cool, dry location. Consult the CoA for lot-specific recommendations.
• Light Sensitivity: The aminothiazole chromophore may be sensitive to prolonged UV exposure. Store in amber vials or away from direct light sources.
• Moisture: Keep the container tightly sealed; use desiccants (silica gel) if storing in humid environments. Hygroscopic uptake can affect accurate weighing.
• Shelf Life: When stored correctly, the solid compound is expected to remain stable for at least 24 months. Verify purity by HPLC or NMR before use in critical experiments if the compound has been stored for extended periods.
• DMSO Stock Stability: Aliquot DMSO stocks and store at –20 °C; limit freeze–thaw cycles to preserve compound integrity.

Quality Control and Troubleshooting

To ensure experimental reproducibility when working with 2-Amino-4-(4-bromophenyl)thiazole, apply the following QC checks and troubleshooting strategies.

Identity Confirmation

• 1H NMR (400 MHz, DMSO-d6): Expect characteristic signals for the thiazole ring proton (~6.9–7.1 ppm), 4-bromophenyl aromatic protons (~7.4–7.6 ppm), and broad NH2 resonance (~7.0–7.5 ppm). Exact chemical shifts should be cross-referenced with the CoA.
• LC-MS: Confirm molecular ion [M+H]+ at m/z 256.0/258.0 (1:1 isotope pattern consistent with one bromine atom).

Purity Assessment

• Analyze by reverse-phase HPLC (C18 column; acetonitrile/water gradient with 0.1% TFA; UV detection at 254 nm). Acceptable purity for most research applications: ≥95%.

Common Issues and Solutions

Issue	Likely Cause	Solution
Incomplete dissolution in DMSO	Insufficient mixing or moisture contamination	Sonicate and warm gently to 37 °C; use anhydrous DMSO
Poor coupling yield	Catalyst deactivation or oxygen contamination	Ensure strict inert atmosphere; use fresh Pd catalyst
Unexpected NMR peaks	Degradation or impurities	Re-check CoA; repurify by column chromatography if needed

Frequently asked questions

What is the best solvent for dissolving 2-Amino-4-(4-bromophenyl)thiazole for cell-based assays?

DMSO is the recommended solvent for preparing stock solutions for cell-based assays. Prepare a 10–50 mM stock in anhydrous DMSO and dilute into culture medium immediately before use, ensuring the final DMSO concentration does not exceed 0.1% (v/v) to avoid solvent cytotoxicity.

Can 2-Amino-4-(4-bromophenyl)thiazole be used directly in Suzuki–Miyaura cross-coupling reactions?

Yes. The aryl bromide at the para-position of the pendant phenyl ring is a competent electrophile for Suzuki–Miyaura coupling with arylboronic acids under standard Pd-catalyzed conditions. The 2-amino group on the thiazole ring typically does not interfere under these conditions, but reaction conditions should be optimized for each specific substrate pair.

How should I confirm the purity of A140256 before use in a critical experiment?

Check the Certificate of Analysis (CoA) provided with the product for purity data. For additional verification, analyze a small sample by reverse-phase HPLC (C18 column, acetonitrile/water gradient, UV 254 nm) and confirm identity by 1H NMR or LC-MS. The compound should show ≥95% purity for reliable research results.

What is the recommended storage temperature for 2-Amino-4-(4-bromophenyl)thiazole?

The compound should be stored at room temperature (15–25 °C) or at 2–8 °C in a cool, dry, and dark location, with the container tightly sealed. Always consult the lot-specific CoA for definitive storage conditions.

Is 2-Amino-4-(4-bromophenyl)thiazole hazardous, and what PPE is required?

While the compound is not classified as highly acutely toxic, it contains an aryl bromide and should be handled with care. Wear nitrile gloves, a lab coat, and safety goggles, and work in a well-ventilated fume hood. Consult the current SDS from Aladdin Scientific for complete hazard classification and first-aid measures.

References

1. Aladdin Scientific Certificate of Analysis for 2-Amino-4-(4-bromophenyl)thiazole, SKU A140256. Aladdin Scientific, Shanghai.
2. Comprehensive Organic Transformations: A Guide to Functional Group Preparations, 3rd ed. Larock, R.C. Wiley-VCH. (General reference for acylation and cross-coupling of aminothiazoles.)
3. Miyaura, N.; Suzuki, A. Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. Chem. Rev. 1995, 95, 2457–2483. doi:10.1021/cr00039a007

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.