Used primarily as an acylating agent in organic synthesis, particularly in the preparation of esters and amides. It is effective in peptide synthesis where it helps protect functional groups and facilitates coupling reactions. Commonly employed in pharmaceutical manufacturing for modifying molecular structures to enhance bioavailability or stability. Also utilized in the production of agrochemicals and specialty polymers due to its reactivity with alcohols and amines. Requires careful handling due to its moisture sensitivity and potential to release phosgene upon decomposition.