Crotonoyl chloride is widely used in organic synthesis as a versatile reagent for introducing the crotonyl group into various molecules. It is particularly valuable in the preparation of pharmaceuticals, agrochemicals, and specialty chemicals. The compound is employed in acylation reactions, where it reacts with alcohols, amines, and other nucleophiles to form crotonyl esters, amides, and other derivatives. These derivatives are often intermediates in the synthesis of biologically active compounds, including drugs targeting inflammation, cancer, and infectious diseases. Additionally, crotonoyl chloride is used in polymer chemistry to modify polymers and create functional materials with specific properties. Its reactivity and ability to form stable bonds make it a key component in the development of advanced chemical products.