Cinnamic acid was synthesized from benzaldehyde and malonic acid as the raw material, and the organic weak - base such as pyridine as the catalyst by Knoevenagel reaction. The main objective of this paper is to improve the synthetic technique of cinnamic acid, reduce the reaction temperature and enhance the yield and purity of the product. Meanwhile, the influence of various weak - base catalysts on yield of cinnamic acid was compared and analyzed. The results indicated that pyridine was the optimal catalyst. Furthermore, in the presence of the...