Used primarily as a key intermediate in the synthesis of pharmaceuticals, especially in the production of anticoagulant drugs and vitamin K antagonists. It serves as a building block in organic reactions where a substituted benzofuranone structure is required. Its cyclic ester structure allows for ring-opening and functionalization, making it valuable in medicinal chemistry for developing bioactive molecules. Also utilized in the preparation of specialty polymers and agrochemicals due to its stability and reactivity profile.