1. Improper reaction conditions: In the preparation of cinnamic acid, reaction conditions such as reaction temperature, reaction time and reactant ratio will affect the yield. If the reaction conditions are improper, such as too high or too low reaction temperature, insufficient or too long reaction time, etc. The yield may decrease.
2. Impure reactant quality: If the reactant quality is impure, such as impurities, moisture or oxides, it will affect the progress of the reaction and improve the yield.
3. Improper use of catalyst: Catalyst plays an important role in allylation reaction, but if the quality of catalyst is not good or the dosage is not appropriate, the reaction yield will be reduced.
4. Occurrence of side reactions: During the reaction, besides cinnamic acid, by-products may also be produced. If the speed of side reaction is faster than that of cinnamic acid, the yield of cinnamic acid will decrease.
5. Poor control of reaction environment: When preparing cinnamic acid, it needs to be carried out under strict reaction environment, otherwise any external factors may affect the progress of the reaction and the improvement of yield.
It is necessary to find out the reasons according to the specific situation and then take corresponding improvement measures.