2-Chloroethyl isothiocyanate is primarily used in organic synthesis as a versatile reagent for introducing the isothiocyanate functional group into various compounds. It is particularly valuable in the preparation of thiourea derivatives, which are important intermediates in the synthesis of pharmaceuticals, agrochemicals, and other bioactive molecules. The compound’s reactivity with amines allows for the creation of thioureas, which are often utilized in drug development for their potential therapeutic properties, such as antimicrobial, antiviral, and anticancer activities. Additionally, it is employed in the synthesis of heterocyclic compounds, which are crucial in medicinal chemistry. Its applications also extend to research settings, where it is used to study biochemical pathways and enzyme inhibition due to its ability to modify proteins and peptides.