1. To master the basic principles and reaction mechanism of esterification reaction.

2. To master the preparation of benzyl cinnamate.

3. Master the method of separation and purification of organic substances.

Two, experimental principle

Esterification reaction is a class of carboxylic acids and alcohols in the presence of a catalyst in the chemical reaction to produce esters and water. In this experiment, benzyl alcohol forms benzyl cinnamate by esterification reaction with cinnamic acid catalyzed by sulfuric acid.

Three experimental steps

1. Cinnamic acid and benzyl alcohol were weighed and put into a reaction bottle in molar ratio (1:1.2) and a small amount of sulfuric acid catalyst was added.

2. The reaction bottle was heated with a counter-current condenser, and the temperature in the reaction bottle was kept at 75-80°C for 2-3 hours.

3. The reaction bottle was cooled to room temperature, 5% sodium hydroxide solution and appropriate amount of phenethyl alcohol were added, and the reaction solution was shaken well so that the reaction solution showed dark yellow color.

4. Transfer to a separatory funnel to separate the organic and inorganic phases.

5. The organic phase was filtered and dried with anhydrous sodium chloride.

6. The solvent was evaporated with a rotary evaporator to obtain benzyl cinnamate.

IV. Analysis of experimental results

Verified by thin-layer chromatography and infrared spectroscopy, a pure product of benzyl cinnamate was obtained, which indicated that the reaction was successful and the yield reached more than 90%.

V. Experimental Precautions

1. The reaction flask and dispensing funnel must be dry to avoid water affecting the reaction yield.

2. Sodium hydroxide solution must be added in small amount to avoid acid-base reaction with the ester to generate the solution foam back to the separatory funnel, affecting the results.

3. During evaporation, overheating must be prevented from causing degradation of the product, but also to ensure that the anhydrous sodium chloride is dry enough.

6. Experimental conclusions

This experiment successfully prepared benzyl cinnamate, and its separation and purification, and obtained qualified products, for the subsequent organic synthesis and analysis to provide a basis.