PhCOCOPh

PhCOCOPh, commonly known as benzil, is an organic compound featuring two phenyl groups linked by a 1,2-diketone moiety. Its formula is C14H10O2, and the structure is symmetric: Ph-CO-CO-Ph. Benzil is a diaryl diketone and serves as a classic example of a 1,2-diketone in organic chemistry.

Benzil is typically prepared by the oxidation of benzoin (Ph-CHOH-CO-Ph) using oxidants such as nitric acid or manganese dioxide. Industrial routes often involve oxidation of the corresponding α-hydroxy ketone or related benzaldehyde derivatives under oxidative conditions. It can also be prepared by photochemical or catalytic methods in some synthetic settings.

Physically, benzil appears as a yellow to pale yellow crystalline solid. It is sparingly soluble in water and readily dissolves in a range of organic solvents, including acetone, benzene, and chloroform. It is relatively stable under normal laboratory conditions but should be kept away from strong reducing agents and moisture-sensitive environments.

Benzil participates in several notable reactions and applications. It undergoes the benzil–benzilic acid rearrangement when treated with base to give benzilic acid, a reaction of historical and synthetic significance. In modern practice, benzil is used as a photoinitiator in polymerization processes (Type II initiation) and as a versatile building block in organic synthesis, enabling various condensations and cyclization reactions to construct more complex structures.

Safety considerations include handling benzil as an irritant; exposure may affect the skin, eyes, or respiratory tract. It should be used with appropriate personal protective equipment and under suitable ventilation.