Abstract:

Using salicylic acid and acetic anhydride as raw materials, silica gel as a catalyst, and microwave technology as an optimization method, the university organic chemistry teaching experiment of 'Preparation and Characterization of Acetylsalicylic Acid' was improved. Through the experiment, the impact of factors such as microwave power, reaction time, and raw material ratio on the final yield was explored. The optimal experimental conditions were determined as follows: silica gel with a particle size of 100-200 mesh, 0.25 g in quantity, 60 s reaction time, 70℃ reaction temperature, 500 W microwave power, and a molar ratio of acetic anhydride to salicylic acid of 2 : 1. The average yield was approximately 68.0%. Compared to the conventional heating method for the preparation of acetylsalicylic acid, microwave-assisted synthesis offers advantages such as simplicity, shorter reaction time, higher product yield, fewer impurities, and environmental friendliness. Introducing this microwave experiment into undergraduate organic chemistry laboratory teaching can broaden students' horizons, enrich experimental teaching content, and further improve the teaching level.

Key words: Microwave, Silica gel, Acetylsalicylic acid, Green chemistry