4-Aminobenzophenone CAS 1137-41-3

Product Overview

4-Aminobenzophenone (p-aminobenzophenone, 4-benzoylaniline, CAS 1137-41-3) is an aromatic ketone with a primary amino group in the para position, having the molecular formula C13H11NO. It is produced industrially by the Friedel-Crafts acylation of aniline with benzoyl chloride, or by reduction of 4-nitrobenzophenone. The commercial product is a yellow to light brown crystalline powder. 4-Aminobenzophenone is a versatile chemical intermediate containing both a reactive amino group and a benzophenone chromophore, making it valuable for pharmaceutical synthesis, UV-absorbing polymers, and specialty dyes. Its amino group readily undergoes diazotization, acylation, and condensation reactions.

Specifications

Each batch is tested by HPLC for purity and impurities, Karl Fischer for moisture, and melting point determination. A COA is provided with every shipment.

Applications

Pharmaceutical Intermediates

4-Aminobenzophenone is a key intermediate in the synthesis of various pharmaceutical compounds, including antihistamines, antimalarials, and central nervous system agents. Its amino group is used to build heterocyclic rings such as benzodiazepines and quinazolines. It is also used in the production of benzophenone-derived drugs with UV-absorbing and photosensitizing properties. Typical reactions include acylation, reductive amination, and diazotization followed by coupling.

UV Absorbers & Photoinitiators

Raw material for the production of benzophenone-type UV absorbers and photoinitiators used in coatings, plastics, and adhesives. 4-Aminobenzophenone derivatives absorb UV light in the 280-350 nm range and are used as light stabilizers in polymers. The amino group can be functionalized to attach the UV absorber to polymer backbones, preventing migration and blooming. Also used in the synthesis of water-soluble photoinitiators for UV-curable coatings.

Dyes & Pigments

Intermediate for the production of azo dyes and disperse dyes. 4-Aminobenzophenone undergoes diazotization to form diazonium salts, which couple with naphthols and other coupling components to produce yellow and orange dyes. The benzophenone group provides good light fastness and thermal stability to the resulting dyes. Used in textile dyes for polyester and acetate fibers.

Other Uses

Reagent in organic synthesis for the preparation of Schiff bases, imines, and amides. Used in the production of corrosion inhibitors, rubber antioxidants, and as a crosslinking agent for epoxy resins. Also used in analytical chemistry as a derivatization reagent for the detection of aldehydes and ketones.

Safety, Handling & Storage

Store in a cool, dry, well-ventilated area in tightly sealed containers, protected from light. 4-Aminobenzophenone is stable under normal storage conditions but may darken on exposure to air and light. Keep away from strong oxidizing agents, strong acids, and strong bases. Use corrosion-resistant equipment (stainless steel, HDPE, or glass). Shelf life is 24 months under proper storage conditions. Wear protective gloves, safety glasses, and dust mask when handling. Avoid inhalation of dust and prolonged skin contact. 4-Aminobenzophenone may cause skin and eye irritation and may be harmful if swallowed. In case of eye contact, flush with water for 15 minutes. 4-Aminobenzophenone is not classified as a dangerous good for transport under most regulations.

FAQ

What is the difference between 4-aminobenzophenone and 2-aminobenzophenone?

4-Aminobenzophenone (CAS 1137-41-3) has the amino group in the para position relative to the carbonyl, while 2-aminobenzophenone (CAS 2835-77-0) has it in the ortho position. The para isomer is more commonly used in pharmaceutical synthesis and UV absorbers due to its linear structure and stronger UV absorption. The ortho isomer is used primarily in the synthesis of benzodiazepines and other heterocyclic compounds where intramolecular hydrogen bonding is important. They are not interchangeable in most applications.

Can 4-aminobenzophenone be used as a photoinitiator directly?

4-Aminobenzophenone itself is not commonly used as a direct photoinitiator, but it is a precursor for more effective amine synergists and benzophenone photoinitiators. Derivatives such as 4,4′-bis(dimethylamino)benzophenone (Michler’s ketone) are widely used as photoinitiators in UV-curable systems. 4-Aminobenzophenone is typically functionalized to improve solubility, reactivity, and compatibility with resin systems before use as a photoinitiator.

What is the minimum order quantity?

Standard packaging is 25 kg fiber drums with polyethylene liners. Full container loads are available for bulk orders. Smaller quantities (1 kg, 5 kg) are available for laboratory and qualification testing. Due to its specialized nature, 4-aminobenzophenone may be produced to order with lead times of 2-4 weeks.