Used primarily as an intermediate in the synthesis of tricyclic antidepressant drugs, particularly in the production of phenothiazine-class pharmaceuticals. Its structure supports the formation of bioactive molecules with central nervous system activity. It is also employed in research for developing photochromic compounds and dyes due to its conjugated aromatic system and light-sensitive properties. In addition, it serves as a building block in organic synthesis for creating complex heterocyclic systems used in medicinal chemistry.