5-Chloro-2-benzothiazolinone: Handling & Application Protocol

5-Chloro-2-benzothiazolinone is a chlorinated heterocyclic thioamide building block widely employed in medicinal and synthetic chemistry for the preparation of bioactive benzothiazole derivatives, antimicrobial agents, and enzyme-inhibitor scaffolds.

CAS Number

6012-42-6

Molecular Formula

C₇H₄ClNOS

Molecular Weight

185.63 g/mol

Appearance

Off-white to pale yellow crystalline solid

Key Functional Groups

Thioamide (C=S), aromatic C–Cl, cyclic N–C bond

Recommended Storage

Cool, dry, dark conditions; tightly sealed; room temperature or 2–8 °C for long-term storage

Aladdin SKU

C132320

Safety & Handling Precautions

Before working with 5-Chloro-2-benzothiazolinone (SKU: C132320), consult the current Safety Data Sheet (SDS) provided by Aladdin Scientific. Observe the following precautions:

• Personal Protective Equipment (PPE): Wear nitrile gloves, a lab coat, and safety glasses at all times. Use a dust mask or half-face respirator when weighing powders to avoid inhalation of fine particles.
• Ventilation: All weighing and dissolution steps should be performed inside a functioning chemical fume hood to prevent accumulation of vapors or dust.
• Skin & Eye Contact: In the event of skin contact, wash the affected area immediately with soap and water for at least 15 minutes. For eye contact, irrigate continuously with water and seek medical attention.
• Waste Disposal: Dispose of all waste—including contaminated gloves, vials, and solvent-containing waste—in accordance with local environmental regulations for halogenated organic compounds.
• Incompatibilities: Avoid contact with strong oxidizing agents, strong bases, and moisture during storage to prevent decomposition.

Review flag: Specific GHS hazard classifications for this compound should be verified against the current SDS before use.

Solubility & Solution Preparation

5-Chloro-2-benzothiazolinone is a solid thioamide derivative. Follow the steps below to prepare stock and working solutions:

1. Solvent Selection: The compound shows good solubility in polar aprotic solvents such as dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF). Limited solubility is expected in water and aliphatic hydrocarbons. If aqueous compatibility is required, prepare a concentrated stock in DMSO and dilute into aqueous buffer immediately before use, keeping the final DMSO content ≤1% v/v to minimise co-solvent effects on biological assays.
2. Stock Solution Preparation:
   a. Accurately weigh the required amount of C132320 using a calibrated analytical balance inside a fume hood.
   b. Transfer to a clean, dry, amber glass vial.
   c. Add the calculated volume of DMSO to achieve the desired concentration (e.g., 10–100 mM stock).
   d. Vortex gently until the solid is fully dissolved. Warm briefly to 30–37 °C in a water bath if needed to assist dissolution; avoid exceeding 50 °C.
   e. Filter through a 0.22 µm PTFE syringe filter if a sterile solution is required.
3. Aliquoting & Storage: Divide the stock solution into single-use aliquots in microcentrifuge tubes, seal with Parafilm, and store at −20 °C. Avoid repeated freeze–thaw cycles.
4. Working Solution: Dilute aliquots into the appropriate vehicle or buffer immediately before each experiment. Verify compound integrity periodically by TLC or HPLC if long-term stability is a concern.

Review flag: Specific solubility values (mg/mL) in listed solvents have not been confirmed from the source material and should be experimentally verified or sourced from validated literature.

Research Applications & Experimental Use

5-Chloro-2-benzothiazolinone serves as a versatile intermediate in synthetic and medicinal chemistry research. Key applications include:

• Synthesis of Benzothiazole Derivatives: The thioamide and ring-chlorine functionalities make C132320 a reactive precursor for nucleophilic substitution and condensation reactions, enabling access to diverse benzothiazole scaffolds used in drug discovery programs.
• Antimicrobial & Antifungal Research: Benzothiazolinone cores are well-documented pharmacophores with reported antimicrobial activity. C132320 can serve as a starting material for synthesising analogue libraries for minimum inhibitory concentration (MIC) screening against bacterial and fungal strains.
• Enzyme Inhibition Studies: Derivatives of 2-benzothiazolinone have been investigated as inhibitors of various enzyme classes. C132320 may be used as a building block to prepare candidates for kinase, protease, or other target-based inhibitor assays.
• Heterocyclic Chemistry Research: The compound is useful for studying ring-opening/ring-closing reactions, electrophilic aromatic substitution at C-5 (facilitated by the existing chlorine), and thioamide reactivity in heterocyclic systems.
• General Coupling Reactions: The reactive C–Cl bond and thioamide group allow participation in palladium-catalysed cross-coupling (e.g., Suzuki, Buchwald–Hartwig) and transition-metal-free substitution reactions for library synthesis.

Review flag: Specific biological activity data (e.g., MIC values, IC₅₀ values) for 5-Chloro-2-benzothiazolinone itself are not provided in the source material. Claims regarding antimicrobial and enzyme inhibitory activity refer to the benzothiazolinone compound class in general and should be supported by primary literature before making specific assertions.

Quality Control & Analytical Verification

To confirm compound identity and purity before use, the following analytical methods are recommended:

• Thin-Layer Chromatography (TLC): Run the compound on silica gel TLC plates using an appropriate eluent system (e.g., ethyl acetate/hexane mixtures). Visualise under UV light (254 nm) and/or with a suitable staining reagent. A single, well-defined spot indicates acceptable purity.
• Melting Point Determination: Compare the observed melting point with the literature or certificate of analysis (CoA) value. A sharp, reproducible melting point is an indicator of compound purity.
• NMR Spectroscopy: ¹H and ¹³C NMR spectra in deuterated DMSO (DMSO-d₆) or CDCl₃ will confirm structural identity. Key signals include aromatic protons and C=S carbon resonance.
• HPLC Purity Assessment: Reverse-phase HPLC (C18 column, acetonitrile/water gradient, UV detection at 254 nm) provides a quantitative purity estimate. Purity ≥95% is generally acceptable for synthetic applications.
• Mass Spectrometry: ESI-MS or APCI-MS should confirm the expected molecular ion (M+H)⁺ or (M−H)⁻ corresponding to the molecular weight of 185.63 g/mol.

Always cross-reference analytical results with the Certificate of Analysis (CoA) supplied by Aladdin Scientific for lot-specific quality data.

Review flag: Specific melting point value and NMR chemical shift assignments for 5-Chloro-2-benzothiazolinone are not provided in the source material and should be verified from the CoA or primary literature.

Storage, Stability & Shelf Life

Proper storage is essential to maintain the integrity of 5-Chloro-2-benzothiazolinone over time:

• Short-Term Storage: Store in a tightly sealed container at room temperature in a cool, dry, and dark location away from heat sources and direct sunlight.
• Long-Term Storage: For extended periods, storage at 2–8 °C (refrigerator) in a sealed, moisture-proof container is recommended to slow any potential degradation.
• Moisture Sensitivity: The thioamide functionality may be susceptible to hydrolysis under prolonged exposure to moisture. Always reseal the container promptly after use and consider storing with a desiccant (e.g., silica gel).
• Light Sensitivity: Store in amber glass vials or wrapped containers to minimise photodegradation.
• Shelf Life: Check the expiry date on the Aladdin Scientific product label and CoA. Verify compound integrity by analytical methods (TLC, HPLC) if the reagent has been stored for an extended period or if any discolouration or caking is observed.
• Solution Stability: DMSO stock solutions should be used within 1–3 months when stored at −20 °C; prepare fresh aqueous dilutions immediately before use.

Review flag: Specific shelf-life duration and solution stability timelines are not confirmed in the source material and should be verified experimentally or from validated supplier data.

Frequently asked questions

What solvents are recommended for dissolving 5-Chloro-2-benzothiazolinone (C132320)?

5-Chloro-2-benzothiazolinone dissolves well in polar aprotic solvents such as DMSO and DMF, making these the preferred choices for preparing stock solutions. For biological assays requiring aqueous conditions, prepare a concentrated DMSO stock and dilute into aqueous buffer immediately before use, keeping the final DMSO content at or below 1% v/v.

What are the primary research applications of 5-Chloro-2-benzothiazolinone?

This compound is primarily used as a synthetic intermediate in medicinal and heterocyclic chemistry. It serves as a building block for preparing benzothiazole derivatives, antimicrobial agent analogues, and enzyme inhibitor candidates. Its reactive C–Cl bond and thioamide group also enable participation in cross-coupling and nucleophilic substitution reactions for library synthesis.

How should 5-Chloro-2-benzothiazolinone be stored to ensure long-term stability?

The compound should be stored in a tightly sealed, amber glass container in a cool, dry, and dark location. For long-term storage, a temperature of 2–8 °C is recommended. Protect from moisture to prevent hydrolysis of the thioamide group, and always reseal promptly after use. Store with a desiccant if the storage environment is humid.

What PPE is required when handling 5-Chloro-2-benzothiazolinone?

At minimum, nitrile gloves, a laboratory coat, and safety glasses should be worn at all times. When weighing powders, use a dust mask or half-face respirator to avoid inhalation. All operations should be carried out in a functioning chemical fume hood. Consult the current SDS for comprehensive hazard and first-aid information.

How can I verify the purity and identity of 5-Chloro-2-benzothiazolinone (C132320) upon receipt?

Upon receipt, cross-reference the product with the Certificate of Analysis (CoA) provided by Aladdin Scientific for lot-specific purity data. Additional in-house verification can be performed by TLC (single spot under UV at 254 nm), melting point determination, ¹H/¹³C NMR spectroscopy, and reverse-phase HPLC (purity ≥95% is generally acceptable for synthetic use).

References

1. Aladdin Scientific Product Page: 5-Chloro-2-benzothiazolinone, SKU C132320. Aladdin Scientific, Shanghai.
2. Joule J.A., Mills K. Heterocyclic Chemistry, 5th ed. Wiley-Blackwell, 2010. (General reference for benzothiazole chemistry.)
3. Narasimhan B. et al. Benzothiazole: a versatile pharmacophore. Expert Opin. Ther. Pat. 2012. (General review of benzothiazole biological activity.)

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