3-Hydroxyphenylacetic acid is an organic compound featuring a phenyl ring substituted with a hydroxymethyl group at the meta position and a carboxylic acid group. It is a white to off-white crystalline powder. This compound serves as a versatile chemical intermediate, particularly in the pharmaceutical industry. It is a key building block in the synthesis of various active pharmaceutical ingredients (APIs). For instance, it is used in the production of certain beta-adrenergic blocking agents (beta-blockers) and other drug candidates. Its structure, containing both phenolic and carboxylic acid functionalities, allows for diverse chemical modifications, making it a valuable synthon in organic synthesis for constructing more complex molecules. As a bifunctional molecule, it is also employed in material science research and as a starting material for the synthesis of fine chemicals. Standard safety precautions for handling organic acids and phenols should be observed.