4-Acetylphenylboronic acid CAS 149104-90-5 98% Off-White to Yellowish Crystalline Powder for Suzuki Coupling & Pharmaceutical Intermediate

1. Product Overview

4-Acetylphenylboronic acid (CAS No. 149104-90-5) is an aromatic boronic acid derivative with the molecular formula C₈H₉BO₃ and a molecular weight of 163.97 g/mol. It typically appears as an off‑white to pale yellow crystalline powder and may contain varying amounts of its boronic acid anhydride. This compound is a widely used building block in palladium‑catalyzed Suzuki–Miyaura cross‑coupling reactions for constructing biaryl frameworks, and also serves as a valuable intermediate in pharmaceutical synthesis, liquid crystal materials, and enzyme inhibition studies (notably as a carbonic anhydrase II inhibitor).

Key Identifiers:

• CAS Number: 149104-90-5

• EINECS Number: 629-086-3

• MDL Number: MFCD01074667

• Molecular Formula: C₈H₉BO₃

• Molecular Weight: 163.97 g/mol

• Synonyms: 4-Acetylbenzeneboronic acid; 4-Boronoacetophenone; p-Acetylphenylboronic acid

2. Key Features and Advantages

• High Reactivity in Cross‑Coupling: Excellent substrate for Suzuki–Miyaura reactions to form C–C bonds and synthesize biaryl compounds central to APIs and functional materials.

• High Purity Available: Typically supplied at ≥98% or ≥99% purity (HPLC), suitable for both research‑grade and industrial‑scale organic synthesis.

• Versatile Intermediate: The acetyl group and boronic acid moiety allow orthogonal functionalization, enabling step‑wise elaboration in multi‑step syntheses.

• Well‑Documented Profile: Established melting point (240–244 °C lit.), solubility, and stability data support reproducible experimental design.

• Broad Utility: Beyond coupling chemistry, it is studied as a carbonic anhydrase II inhibitor and used in mechanochemical cocrystal formation with amino acids.

3. Main Applications

• Suzuki–Miyaura Cross‑Coupling: Primary reagent for Pd‑catalyzed biaryl synthesis in pharmaceutical R&D, agrochemicals, and advanced materials (OLED/LCD liquid crystal intermediates).

• Pharmaceutical Intermediate: Building block for active pharmaceutical ingredients, especially those requiring aryl–aryl linkages or boronic acid pharmacophores.

• Enzyme Inhibition Research: Investigated as a potent inhibitor of carbonic anhydrase II (CA II), with IC₅₀ values of ~246 μM (bovine) and ~281 μM (human).

• Materials Science: Precursor for conjugated aromatic systems in organic electronics and liquid crystal compounds.

• Academic & Industrial Organic Synthesis: General-purpose arylboronic acid for teaching labs, method development, and custom synthesis projects.

4. Technical Specifications

5. Storage and Handling

• Storage Conditions: Store in a cool, dry place protected from light. Recommended temperature: 2–8 °C (refrigerated) or at least “keep cold”; seal tightly to prevent moisture uptake, since boronic acids can slowly anhydrize or hydrolyze. For long‑term stability, keep under inert atmosphere (N₂ or Ar) in a desiccator.

• Shelf Life: Stable for extended periods when stored dry, dark, and cool; typical shelf life 12–24 months unopened.

• Handling Precautions: Handle in a well‑ventilated area or fume hood. Avoid dust generation. Use personal protective equipment: N95 dust mask (US), safety goggles, gloves, and lab coat. This compound is a mild irritant to eyes, skin, and respiratory system (GHS07, H315‑H319‑H335).

• Packaging: Commonly supplied as 1 g / 5 g / 25 g / 100 g / 500 g / 1 kg in amber glass bottles or double‑sealed foil pouches with desiccant. Industrial lots: 25 kg/fiber drum.

6. Safety Overview

• GHS Classification: GHS07 – Warning. Hazard statements: H315 (causes skin irritation), H319 (causes serious eye irritation), H335 (may cause respiratory irritation).

• Signal Word: Warning

• Precautionary Statements: P261 (avoid breathing dust), P264 (wash after handling), P271 (use only outdoors or in well‑ventilated area), P280 (wear protective gloves/eye protection), P302+P352 (if on skin: wash with plenty of soap and water), P305+P351+P338 (if in eyes: rinse cautiously with water for several minutes; remove contact lenses if present; continue rinsing), P362 (take off contaminated clothing and wash before reuse).

• Risk / Safety Codes (traditional): R36/37/38 (irritating to eyes, respiratory system, skin); S26 (in case of contact with eyes, rinse immediately with plenty of water and seek medical advice), S36 (wear suitable protective clothing), S37/39 (wear suitable gloves and eye/face protection).

• First Aid Measures:

• Inhalation: Move to fresh air. If breathing is difficult, administer oxygen and seek medical attention.

• Skin Contact: Wash off with soap and plenty of water. Remove contaminated clothing.

• Eye Contact: Rinse immediately with flowing water for at least 15 minutes, lifting upper and lower eyelids. Seek medical advice.

• Ingestion: Rinse mouth. Do NOT induce vomiting unless directed by medical personnel. Seek immediate medical attention.

• Firefighting: Use dry chemical, CO₂, water spray, or alcohol‑resistant foam. Wear self‑contained breathing apparatus and full protective clothing.

• Disposal: Dispose of as hazardous chemical waste in accordance with local regulations. WGK Germany 3 (hazardous to waters).