4-Dimethylamino Pyridine Catalyzed Synthesis of Acetyl Salicylic Acid
Abstract: In this paper, the research of optimum conditions in synthesizing the acetylsalicylic acid was done with salicylic acid & acetic anhydride as basic materials and 4-dimethylamino pyridine as catalyst. With single factor changing, The effect of reaction temperature、reaction time、catalyst dosage plus materials’ molar ratio on yield was respectively explored at various levels. On that basis, the orthogonal test of four factors at three different levels was used to get the optimum conditions of reaction temperature 70 ℃、reaction time 60min、the ratio of salicylic acid to catalyst 18% as well as anhydride molar ratio 1:3. Upon these conditions, the yield reaches the maximization of 83.12%.Besides,when treated with FeCl3, the product didn’t present purple,which showed it contain no the phenolic hydroxyl. Furthermore, using environment-friendly 4-dimethyl- amino pyridine as catalyst can improve the catalytic activity、reaction safety plus post-treatment and should be industrialized.
Key words: Acetylsalicylic acid; 4-dimethylamino pyridine; Catalyst; Synthesis
