Ethyl 4-iodo-3-methylbenzoate is primarily used in organic synthesis as a building block for more complex chemical compounds. It serves as an intermediate in the production of pharmaceuticals, particularly in the development of drugs that target specific biological pathways. The iodine atom in the compound makes it a valuable reagent in cross-coupling reactions, such as Suzuki or Sonogashira couplings, which are essential for creating carbon-carbon bonds in medicinal chemistry. Additionally, its ester group allows for further functionalization, making it versatile in the synthesis of fine chemicals and agrochemicals. Researchers also utilize it in the study of aromatic compounds and their reactivity, contributing to advancements in material science and chemical engineering.