Used primarily as an intermediate in the synthesis of pharmaceutical compounds, particularly in the production of the anticonvulsant carbamazepine. Its reactive carbonyl chloride group allows for easy attachment to amines or alcohols, making it valuable in constructing amide or ester linkages in active drug molecules. It is also employed in the development of mood-stabilizing agents and in organic chemistry research for new bioactive substances. Due to its reactivity, it is handled under controlled conditions in non-aqueous environments to prevent hydrolysis.