Used as a key intermediate in the synthesis of pharmaceutical compounds, particularly in the development of kinase inhibitors for cancer treatment. It serves as a building block in medicinal chemistry due to the reactivity of the iodine moiety, enabling cross-coupling reactions such as Suzuki or Heck reactions to introduce diverse aromatic or heteroaromatic groups. Its indolinone core is commonly found in bioactive molecules, making it valuable in drug discovery programs targeting tyrosine kinase pathways. Also explored in the preparation of fluorescent probes and labeled compounds for biochemical assays due to the heavy atom effect of iodine, which can influence photophysical properties.