Used primarily as an acylating agent in organic synthesis, enabling the introduction of both acetyl and propionyl groups in a single step. It is valuable in the production of pharmaceuticals, agrochemicals, and fine chemicals where selective and sequential acylation is required. Its mixed anhydride structure offers advantages in reaction specificity and yield when compared to using separate acetic and propionic anhydrides. Commonly applied in the synthesis of esters and amides, especially in complex molecules where controlled reactivity is essential. Also utilized in the preparation of cellulose derivatives and other polymers requiring specific side-chain modifications.