Used primarily as an intermediate in organic synthesis, trans-Cinnamoyl chloride is key in the preparation of esters and amides for use in pharmaceuticals and agrochemicals. It reacts readily with alcohols and amines to form cinnamate esters and cinnamoyl amides, which exhibit biological activity such as antimicrobial and anti-inflammatory properties. It is also employed in the synthesis of fragrances and flavoring agents due to its aromatic structure. In research, it serves as a reagent for introducing the cinnamoyl group in complex molecules, aiding in the development of functional materials and bioactive compounds.