6-Chloro-1,3-benzoxazol-2-amine: Handling & Application Protocol

6-Chloro-1,3-benzoxazol-2-amine is a halogenated aminobenzoxazole building block widely used in medicinal chemistry for the synthesis of bioactive heterocyclic scaffolds and as a key intermediate in the preparation of kinase inhibitors and antimicrobial candidates.

CAS Number

Not specified in source material — see product datasheet (C193728)

Molecular Formula

C7H5ClN2O

Molecular Weight

168.58 g/mol

Functional Groups

Primary amine (–NH2), benzoxazole ring, aryl chloride

Appearance

Typically a solid powder; exact color should be verified on product datasheet

Key Application

Intermediate in heterocyclic synthesis, medicinal chemistry, and biological screening

SKU

C193728

Materials and Safety Precautions

Before working with 6-Chloro-1,3-benzoxazol-2-amine (Aladdin SKU: C193728), consult the product Safety Data Sheet (SDS) for up-to-date hazard classifications, handling requirements, and first-aid measures. The compound contains an aryl chloride and a primary amine, and should be treated as a potential irritant.

Personal Protective Equipment (PPE): Wear nitrile gloves, a laboratory coat, and safety glasses. Work in a well-ventilated fume hood.

Storage: Store tightly sealed in a cool, dry location away from light and moisture. Confirm specific storage temperature requirements (e.g., room temperature or 2–8 °C) on the product datasheet.

Waste Disposal: Dispose of all waste in accordance with local institutional and governmental regulations for halogenated organic compounds.

Stock Solution Preparation

6-Chloro-1,3-benzoxazol-2-amine has limited solubility in water due to its aromatic heterocyclic structure. The following guidelines are recommended for preparing stock solutions:

1. Solvent Selection: Dissolve the compound preferentially in dimethyl sulfoxide (DMSO) or dimethylformamide (DMF) to achieve concentrations typically in the range of 10–100 mM. For aqueous biological assays, dilute the DMSO stock with aqueous buffer to the desired working concentration, keeping the final DMSO content ≤0.1–1% (v/v) to minimize cytotoxicity. Verify solvent compatibility with your specific assay system.
2. Weighing: Tare a pre-dried microcentrifuge tube. Transfer the required mass of compound and record the exact weight.
3. Dissolution: Add the appropriate volume of solvent. Vortex for 30–60 seconds and, if necessary, sonicate in a water bath (ambient temperature) for 2–5 minutes until a clear solution is obtained.
4. Filtration (optional): If particulates remain, pass the solution through a 0.22 µm PTFE syringe filter.
5. Aliquoting: Prepare single-use aliquots to avoid repeated freeze-thaw cycles and store at –20 °C under inert gas (argon or nitrogen) when long-term storage is required.

Note: Solubility values and exact recommended concentrations have not been specified in the supplied source material and should be confirmed experimentally or via the product datasheet.

Synthetic and Biological Application Procedures

6-Chloro-1,3-benzoxazol-2-amine serves dual roles as a synthetic intermediate and a biological screening compound. Researchers should adapt the following general guidelines to their specific experimental design:

A. Use as a Synthetic Building Block

The aryl chloride at the 6-position makes this compound amenable to transition-metal-catalyzed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig amination) and nucleophilic aromatic substitution (SNAr) reactions. The C-2 amino group can participate in acylation, condensation, or cyclization reactions to elaborate the heterocyclic core.

• Set up reactions under anhydrous, inert-atmosphere conditions (nitrogen or argon) when moisture-sensitive coupling reagents or catalysts are employed.
• Monitor reaction progress by thin-layer chromatography (TLC) or LC-MS.
• Purify products by column chromatography or recrystallization as appropriate.

B. Use in Biological Assays

Aminobenzoxazole derivatives have been investigated as enzyme inhibitors and antimicrobial agents. For in vitro assays:

• Prepare serial dilutions of the compound stock in assay buffer immediately before use.
• Include vehicle (DMSO) controls at matched concentrations.
• Follow assay-specific incubation times, temperatures, and detection methods as defined in the relevant literature or kit instructions.

Specific reaction conditions, yields, and biological activity data are not provided in the source material and must be sourced from peer-reviewed literature appropriate to your application.

Analytical Characterization and Quality Verification

Prior to use in sensitive applications, confirm the identity and purity of 6-Chloro-1,3-benzoxazol-2-amine using the following analytical methods:

• 1H NMR Spectroscopy: Record the spectrum in DMSO-d6 or CDCl3 and compare with literature or in-house reference data. Key signals include the aromatic protons of the benzoxazole ring (typically δ 7.1–7.8 ppm) and the C-2 amino group (broad –NH2 signal).
• LC-MS or GC-MS: Confirm the molecular ion at m/z 168/170 (isotope pattern characteristic of one chlorine atom) and check chromatographic purity (≥95% by area, or as specified on the certificate of analysis).
• HPLC Purity Analysis: Use a reversed-phase C18 column with UV detection at 254 nm or 280 nm. Compare retention time and purity with the certificate of analysis (CoA) provided by Aladdin Scientific.
• Melting Point: Determine and compare with the value stated on the CoA. Deviations may indicate impurities or degradation.

Exact NMR chemical shifts and purity specifications should be verified against the Aladdin Scientific Certificate of Analysis for lot C193728.

Troubleshooting and Storage Recommendations

Poor Solubility: If the compound does not dissolve readily, try warming the solvent to 40–50 °C (for non-volatile solvents such as DMSO) with gentle agitation. Do not heat above 60 °C. Avoid prolonged exposure to aqueous conditions at extremes of pH.

Discoloration or Precipitate Formation: These may indicate degradation or moisture uptake. Discard and use a fresh aliquot. Ensure containers are sealed immediately after use and stored with desiccant.

Low Reaction Yield in Cross-Coupling: Verify catalyst loading, ligand choice, base, and solvent system. Ensure anhydrous conditions and check that the aryl chloride substrate is compatible with the chosen catalytic system (aryl chlorides generally require more active catalysts than aryl bromides or iodides).

Recommended Storage Conditions: Store at the temperature specified on the product datasheet (verify on CoA/datasheet; commonly room temperature or 2–8 °C for aminobenzoxazoles). Protect from light, moisture, and air. Use amber vials or wrap in aluminium foil for light-sensitive storage.

Shelf Life: Follow expiry date stated on the Aladdin Scientific product label. For long-term storage beyond the stated shelf life, re-verify identity and purity before use.

Frequently asked questions

What solvents are recommended for dissolving 6-Chloro-1,3-benzoxazol-2-amine?

DMSO and DMF are the most commonly recommended solvents for dissolving aminobenzoxazole compounds due to their high polarity and ability to solubilize aromatic heterocycles. For aqueous biological assays, prepare a concentrated DMSO stock and dilute into aqueous buffer, keeping the final DMSO concentration at or below 1% (v/v). Verify solubility experimentally, as exact solubility data for this specific compound are not listed in the supplied source material.

Can 6-Chloro-1,3-benzoxazol-2-amine be used in palladium-catalyzed cross-coupling reactions?

Yes, the aryl chloride at the 6-position of the benzoxazole ring is suitable for palladium-catalyzed cross-coupling reactions such as Suzuki–Miyaura and Buchwald–Hartwig reactions, although aryl chlorides generally require more reactive catalyst systems compared with aryl bromides or iodides. Reaction optimization—including catalyst, ligand, base, and solvent selection—is essential. Specific coupling conditions for this compound are not detailed in the source material and should be adapted from peer-reviewed literature.

How should 6-Chloro-1,3-benzoxazol-2-amine be stored to maintain stability?

The compound should be stored tightly sealed, away from light, moisture, and air, at the temperature specified on the Aladdin Scientific product datasheet and Certificate of Analysis. For long-term storage, aliquoting into single-use portions under inert gas (nitrogen or argon) and storing at –20 °C is recommended to prevent degradation from repeated freeze-thaw cycles or moisture ingress. Always verify the specific storage conditions on the product label.

What is the molecular weight and molecular formula of 6-Chloro-1,3-benzoxazol-2-amine?

6-Chloro-1,3-benzoxazol-2-amine has the molecular formula C7H5ClN2O and a molecular weight of approximately 168.58 g/mol. These values should be confirmed against the Certificate of Analysis provided with Aladdin Scientific product C193728.

What analytical methods can confirm the identity and purity of this compound?

Identity and purity can be confirmed by 1H NMR spectroscopy, LC-MS or GC-MS (looking for the characteristic chlorine isotope pattern at m/z 168/170), and reversed-phase HPLC with UV detection. Melting point determination is a useful additional check. All results should be compared against the lot-specific Certificate of Analysis supplied by Aladdin Scientific for product C193728.

References

1. Aladdin Scientific product datasheet and Certificate of Analysis for 6-Chloro-1,3-benzoxazol-2-amine, SKU C193728.
2. General reference: Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press, 2012. (General guidance on heterocyclic chemistry and cross-coupling reactions.)
3. Negishi, E.-I. (Ed.) Handbook of Organopalladium Chemistry for Organic Synthesis; Wiley-Interscience, 2002. (Reference for palladium-catalyzed cross-coupling of aryl chlorides.)

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