it has 2 benzene rings

usually synthesized in the lab from benzoyl chloride and hydrogen peroxide

A benzoylation is a reaction which introduces a benzoyl group into a molecule.

Benzoyl chloride is C6H5COCI and benzyl chloride is C6H5CH3CI

Reaction is:

C6H5COCl + H2O → C6H5CO2H + HCl

So it produces benzoic acid and hydrochlorid acid

Benzoyl peroxide is a very frequently used treatment for acne. If a 10% solution of benzoyl peroxide (such as Oxy 10) causes irritation, use a lower dose of Benzoyl peroxide; anti-acne facial wipes usually contain 2.5% benzoyl peroxide.