Used in organic synthesis as an intermediate for pharmaceuticals and fine chemicals. The aldehyde and hydroxyl groups allow for versatile functionalization, making it suitable for condensation reactions, especially in the formation of Schiff bases. Commonly employed in the development of photochromic and nonlinear optical materials due to its ability to undergo intramolecular proton transfer. Also utilized in the synthesis of heterocyclic compounds and as a building block in medicinal chemistry for iodinated aromatic structures.