Overview and Chemical Identity

5-Chloro-3,3-dimethyl-2,3-dihydro-1H-isoindol-1-one (Aladdin Scientific SKU C174243) is a bicyclic lactam belonging to the isoindolinone class of heterocyclic compounds. The core isoindolin-1-one scaffold consists of a benzene ring fused to a five-membered lactam ring. In this derivative, a chlorine atom is positioned at the 5-position of the aromatic ring, while two methyl groups are geminal substituents at the 3-position of the lactam ring.

These structural features confer useful physicochemical and electronic properties: the electron-withdrawing chloro group modulates ring electronics and provides a handle for further cross-coupling or nucleophilic aromatic substitution reactions, while the gem-dimethyl substitution at C-3 increases steric bulk and metabolic stability around the lactam nitrogen, a consideration of interest in medicinal chemistry programmes.

The calculated molecular formula is C₁₀H₁₀ClNO with a molecular weight of approximately 195.65 g/mol. Researchers should consult the product certificate of analysis (CoA) supplied with each lot for confirmed purity, melting point, and spectroscopic data.

Solubility and Stock Solution Preparation

Isoindolinone derivatives of this class are generally sparingly soluble in water but exhibit good solubility in common organic solvents. The following guidance is based on the solubility behaviour typical of chloro-substituted isoindolinones; researchers must verify solubility experimentally for each application.

• DMSO: Typically the solvent of choice for preparing concentrated stock solutions. Begin with a target concentration of 10–50 mM, vortex thoroughly, and warm gently (37 °C) if dissolution is incomplete. Filter through a 0.2 µm PTFE syringe filter before use in biological assays.
• Ethanol / Methanol: Suitable for intermediate solubility testing and NMR sample preparation. Use sparingly in cell-based assays due to cytotoxicity at higher concentrations.
• Acetonitrile / Acetone: Useful for HPLC sample preparation. Ensure solvent compatibility with the mobile phase.
• Aqueous buffers: Solubility is expected to be low without co-solvent; use ≤1% DMSO (v/v) as co-solvent in buffer-based assays and verify that the co-solvent does not confound results.

Note: Specific solubility values (mg/mL) are not confirmed in the source material. Researchers should conduct nephelometric or shake-flask solubility assays for precise data. Flag for review.

Storage and Stability Guidelines

Proper storage is essential to maintain the chemical integrity of 5-chloro-3,3-dimethyl-2,3-dihydro-1H-isoindol-1-one over its shelf life. Follow the guidance below and always refer to the Safety Data Sheet (SDS) and the CoA supplied with your specific lot for authoritative conditions.

1. Temperature: Store at room temperature (15–25 °C) in a climate-controlled environment unless the CoA specifies refrigerated (2–8 °C) or frozen (−20 °C) storage. Avoid repeated freeze–thaw cycles for solution aliquots.
2. Light: Protect from direct sunlight and UV radiation. Store in the original amber or opaque container, or wrap with aluminium foil.
3. Moisture: Keep the container tightly sealed. Isoindolinone lactams can be susceptible to hydrolysis under prolonged exposure to moisture; use a desiccant if storing in a humid environment.
4. Atmosphere: For long-term storage or after container opening, consider back-filling with inert gas (argon or nitrogen) before resealing.
5. Stock solutions: Aliquot DMSO stock solutions into single-use volumes to avoid repeated freeze–thaw. Store aliquots at −20 °C and use within 3–6 months; verify stability by TLC or HPLC before use in critical experiments.

Caution: Specific stability data and shelf-life for this compound are not confirmed in the source material. The guidance above reflects best practice for compounds of this structural class. Flag for review.

Safety and Waste Disposal

The specific hazard classification of 5-chloro-3,3-dimethyl-2,3-dihydro-1H-isoindol-1-one has not been confirmed in the source material provided. General precautions appropriate for organic halogen-containing lactams are outlined below. Always consult the current SDS before handling.

Personal Protective Equipment (PPE)

• Chemical-resistant gloves (e.g., nitrile, ≥0.1 mm thickness)
• Safety goggles or face shield
• Laboratory coat and closed-toe shoes
• Work in a fume hood to avoid inhalation of dust or vapours

First Aid Measures

• Skin contact: Wash with soap and water for ≥15 minutes; seek medical attention if irritation persists.
• Eye contact: Irrigate with water for ≥15 minutes; seek immediate medical attention.
• Inhalation: Move to fresh air; seek medical attention if symptomatic.
• Ingestion: Do not induce vomiting; seek medical attention immediately.

Waste Disposal

Dispose of compound and contaminated materials as halogenated organic waste in accordance with local, national, and institutional regulations. Do not pour down the drain. Consult your institution's Environmental Health and Safety (EHS) office for approved disposal procedures.

Applications in Synthesis and Medicinal Chemistry

The isoindolinone scaffold is a privileged structure in drug discovery, appearing in a range of bioactive molecules and approved pharmaceuticals. The 3,3-dimethyl substitution pattern, combined with the 5-chloro group, makes this compound a versatile intermediate for:

• N-functionalisation: The secondary lactam nitrogen (N-H) is amenable to alkylation, acylation, or sulfonylation reactions to generate N-substituted isoindolinone libraries.
• Cross-coupling chemistry: The aryl chloride at the 5-position can participate in palladium-catalysed cross-coupling reactions (e.g., Suzuki–Miyaura, Buchwald–Hartwig) to install diverse aryl, heteroaryl, or amino groups.
• Fragment-based drug discovery (FBDD): The compact, rigid bicyclic core with defined substitution points is well-suited as a fragment or fragment-linking intermediate.
• SAR studies: The 3,3-gem-dimethyl group can be used to probe steric and conformational effects relative to unsubstituted or mono-substituted 3-position analogues.

Disclaimer: Specific published biological activity data for this exact compound (C174243) are not confirmed in the source material. Researchers are advised to conduct independent literature searches (e.g., SciFinder, Reaxys, PubChem) to identify reported uses and bioactivity data before designing experiments.