4-Acetamidophenylboronic acid CAS 101251-09-6 Purity 98 percent White to Light Yellow Crystalline Powder Suzuki Coupling Reagent Pharma Intermediate B

1. Product Overview

4-Acetamidophenylboronic acid, CAS 101251-09-6, also known as 4-acetamidobenzeneboronic acid or p-acetamidophenylboronic acid, is the para-substituted arylboronic acid with molecular formula C8H10BNO3 and MW 178.98 g/mol. It appears as white to light yellow or off-white crystalline powder, melting point 215–220 degrees Celsius (lit.), often supplied containing varying amounts of cyclic boroxine anhydride. Freely soluble in methanol, warm ethanol, DMSO; slightly soluble in cold water, better at 70 degrees Celsius (approx. 85 g/L). The para-acetamide (–NHCOCH3) and boronic acid (–B(OH)2) groups make it a key Suzuki–Miyaura cross-coupling reagent and pharmaceutical intermediate for proteasome inhibitors, kinase scaffolds and acetanilide-based APIs. Moisture- and air-sensitive; stored dry under N2 or Ar, refrigerated or frozen.

2. Key Features and Advantages

• Suzuki-Ready Para-Boronate — High-purity 97–98% HPLC; para-acetamide stabilizes aniline nitrogen and modulates electronics for regioselective Pd-catalyzed C–C couplings.

• Pharma Scaffold — Core for p-acetamidobenzeneboronic acid in boron-warhead protease inhibitors, antibacterial/anticancer leads, fragment-based drug discovery.

• Anhydride-Tolerant — Commercial grades intentionally contain varying boroxine; still effective in coupling after pre-treatment if needed.

• Grade Options — Reagent 97–98% HPLC, 96% technical, custom labeled/isotope on inquiry; often shipped as powder to crystal in amber vials under inert.

3. Main Applications

Used in boronic acid and pharma sectors: Suzuki–Miyaura Cross-Coupling (para-aryl–aryl/heteroaryl bonds for APIs, OLED monomers, conjugated polymers); Pharmaceutical Intermediates (p-acetamidobenzeneboronic acid for kinase/antibacterial/anticancer scaffolds, prodrug boronic warheads); Medicinal Chemistry (serine protease/proteasome targeting boron agents, enzyme inhibitor design); Material Science (Suzuki polymerization to para-linked conjugated polymers, MOL/OLED precursors); Custom Synthesis (mg–kg boronic acids for CRO/CDMO, inquire-only; also analytical ref for boronic acid QC).

4. Technical Specifications

5. Storage and Handling

Store in a cool, dry place under inert atmosphere N2 or Ar, sealed in desiccated amber vials. Recommended: 2–8 °C refrigerator for short term, –20 °C for long term; keep from moisture and light. For bulk: foil-pouched with desiccant and Ar. Shelf life ≥12 months unopened at –20 °C under inert gas; reseal tightly after opening. Handle in fume hood, preferably glovebox/N2 blanket; wear nitrile gloves, goggles, lab coat; avoid dust inhalation; keep dry. Incompatible with strong oxidizers, strong acids/bases, moisture.

6. Safety Overview

GHS pictograms GHS07 Exclamation. Signal Word Warning. Hazard statements H315 causes skin irritation, H319 causes serious eye irritation, H335 may cause respiratory irritation. Precautionary P261 P280 P302+P352 P305+P351+P338. Acute toxicity low–moderate for arylboronics; irritant/sensitizer. Transport not DG in small packs; bulk may be UN1325 Flammable Solid Organic n.o.s. PG III. WGK Germany 3. Customs 29319090 organo-boron. For research/pharma intermediate only; dispose as organic irritant hazardous waste. Skin: wash soap/water; eyes: rinse 15 min + medical aid; inhalation: fresh air.