微波辅助H_(2)SO_(4)/AC催化合成乙酰水杨酸的研究

Study on Catalytic Synthesis of Acetylsalicylic Acid with H_(2)SO_(4)/AC under Microwave Irradiation

以煤基活性炭负载浓硫酸为催化剂合成乙酰水杨酸,采用单因素和响应面实验获得较佳的工艺条件。结果表明,该催化剂对乙酰水杨酸收率影响大小程度依次为:催化剂用量(B)>辐射时间(C)>微波辐射功率(D)>酐酸比(A)。较佳反应条件为:反应温度75℃、n(乙酸酐):n(水杨酸)为2:1、催化剂用量0.21 g、辐射时间15.4 min、微波辐射功率247W,收率82.7%。催化剂重复使用5次后,催化收率仍可达80.1%。响应面实验回归拟合模型为:Y=82.24+0.18A+2.79B+1.62C-0.55D-0.60AB-0.58AC-1.05AD-2.25BC+0.38BD+0.38CD-4.49A^(2)-4.72B^(2)-6.26C^(2)-4.43D^(2)。

Salicylic acid and acetic anhydride was used as reagents to synthesize acetylsalicylic acid under active carbon(AC)supported concentrated sulfuric acid.Single factor and response surface experiment were used to obtain the better technology conditions.The results showed that the fourmain factors influencing the yield of acetylsalicylic acid were in the following order:quantity of catalyst>microwave radiation time>the microwave radiation power>acetic anhydride.The optimal technical conditions were as follows:temperature was 75℃,acetic anhydride to sali-cylic acid was 2:1,the quantity of catalyst was 0.21 g,microwave radiation time was 15.4 min,microwave radiation power was 247 W,the yield of acetylsalicylic acid was 82.7%,which was close to the predict value.After the catalyst reuse five times,the yield was 80.1%.Its regression model fitting was Y=82.24+0.18A+2.79B+1.62C-0.55D-0.60AB-0.58AC-1.05AD-2.25BC+0.38BD+0.38CD-4.49A^(2)-4.72B^(2)-6.26C^(2)-4.43D^(2).