In this section, we delve into various methods for synthesizing phenols, particularly focusing on the hydrolysis of diazonium salts obtained from aromatic amines. Converting an aromatic primary amine into a diazonium salt using nitrous acid is the first step. Under mild conditions, typically through hydrolysis with water or dilute acids, these diazonium salts can yield phenols. The section also touches on alternative routes for phenol production, such as the transformation of haloarenes and the sulfonation-alkylation route from benzene sulfonic acids. The industrial importance of phenols, their derivatives, and their applications in various chemical production processes are emphasized.