Abstract: This paper used orthogonal test to carry out optimization design of concentrated sulfuric acid catalytic synthesis and microwave radiation synthesis ethyl salicylate. This experiment used L25(54) orthogonal table to complete the strong sulfuric acid catalysis synthesis of ethyl salicylate. After through compare different influence factors of the esterification, such as different proportion of salicylic acid and ethanol, stirring rate, the amount of catalyst, and selection the orthogonal experiment scheme of four factors and five levels, we obtained the optimal conditions for synthesis of ethyl salicylate: molar ratio of 1:5, stirring rate of 160r/min, catalyst amount of 9mL, reaction time of 11 hours, and the yield of approximately 64%. And used L16(44) orthogonal table to complete microwave radiation synthesis ethyl salicalate. Then we compared the influences of the different proportion of salicylic acid and ethanol, the reaction power, the amount of catalyst, and the reaction time on the esterification yield. We selected the orthogonal experiment scheme of four factors and four levels, and obtained the optimal conditions for synthesis of ethyl salicylate: molar ratio of 1:7, radiation power of 65W, catalyst amount of 11mL, reaction time of 10min, the yield of approximately 65.26%. The results showed microwave radiation technology applied to esterification with the advantages of shorter reaction time, higher reaction yields than catalyzed synthesis.
Key words:Ethyl salicylate; Microwave reaction; Catalytic esterification; Orthogonal design