4Methoxybenzophenone

4-Methoxybenzophenone is an organic compound with the chemical formula C₁₄H₁₂O₂. It belongs to the class of benzophenones, which are derivatives of benzophenone (diphenylmethanone) with additional substituents. This compound features a methoxy group (–OCH₃) attached to the para position of one of the benzene rings, giving it distinct chemical and physical properties.

Synthetically, 4-methoxybenzophenone is prepared through the Friedel–Crafts acylation of anisole (methoxybenzene) with benzoyl chloride in the presence of a Lewis acid catalyst, such as aluminum chloride. It can also be synthesized via the reaction of phenylmagnesium bromide (a Grignard reagent) with methyl benzoate, followed by hydrolysis. The compound is typically isolated as a white to off-white crystalline solid with a melting point around 50–55°C.

4-Methoxybenzophenone is notable for its photochemical properties, particularly its ability to absorb ultraviolet (UV) light. This characteristic makes it useful in various applications, including UV filters in sunscreens, photoresists in lithography, and as a photoinitiator in polymer synthesis. Its UV-absorbing behavior arises from the extended conjugation of the benzophenone chromophore, which facilitates electronic transitions upon light absorption.

In terms of safety, 4-methoxybenzophenone is generally considered low in acute toxicity, though prolonged exposure or improper handling may pose risks. It is soluble in organic solvents like ethanol and acetone but poorly soluble in water. The compound is also sensitive to oxidation and should be stored in a cool, dry environment, protected from light.

Research into 4-methoxybenzophenone continues, particularly in areas involving photochemistry, materials science, and organic synthesis, where its tunable properties make it a valuable intermediate or functional additive.