Synthesis of acetosalicylic acid over ultrasound-assisted AlCl3 modified cation exchange resin
XIANG Bai-lin1,2, CHI Qiang1, LI Wei1, XIAO Ya-ting1, CHEN Gui1
1. College of Chemistry and Materials Engineering, Huaihua University, Huaihua 418000, China; 2. College of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
Abstract: Acetosalicylic acid is synthesized by using salicylic acid and acetic anhydride as raw materials,alchlor modified cation exchange resin as catalyst assisted by ultrasound irradiation.As is shown in the results of characterization by means of Fourier transform infrared spectrum and thermogravimetric,the skeleton structure of the resin has experienced little changes after it is modified by AlCl3 with complexation reaction.The maximum yield of acetosalicylic acid can reach 84.4% under the following optimal reaction conditions that the molar ratio of acetic anhydride to salicylic acid is 2.5:1,reaction lasts for 20 minute,reaction temperature is set at 75℃,the mass amount of catalyst is 8% that of salicylic acid,ultrasonic power is 50 W and crystallization time spends 2 h.The catalyst can be reused for five times and still remains high catalytic activity.This method exhibits better catalytic performance than traditional methods,which has no humic acid emissions.The product is easy to separate,the post-treatment process is simple,and the recycling rate of catalyst stays high.