Used as a key intermediate in the synthesis of pharmaceutical compounds, particularly in the development of kinase inhibitors for cancer treatment. Its structure allows for selective modification, making it valuable in creating targeted therapies. Also employed in materials science for designing organic semiconductors due to the electron-deficient nature of the thienopyrimidine core. Commonly utilized in cross-coupling reactions such as Suzuki or Buchwald-Hartwig to build complex molecules in drug discovery and electronic materials.