Experiment purpose:

1. To understand the principle and conditions of esterification reaction, and to master the esterification reaction between different acids and alcohols.

2. Familiarize with the preparation method and procedure of ethyl cinnamate.

3. Master the basic operation skills of organic synthesis experiments and laboratory safety.

Experimental principle:

Esterification is a chemical reaction in which an alcohol and an acid react to form an ester. Acids and alcohols condense to form esters, in which the acid undergoes an acylation reaction that creates an ester bond and releases a molecule of water. This is an acid-catalyzed process that does not occur under alkaline conditions. The reaction equation for this experiment is as follows:

Cinnamic acid + ethanol → ethyl cinnamate + H2O

Experimental equipment:

Dispensing funnel, reaction flask, glass rod, burette, wash flask, hot water bath, funnel, and lab supplies.

Experimental procedure:

1. Weigh cinnamic acid (2.2g) and add it to the glass reaction flask;

2. Take an appropriate amount of ethanol and add it to the reaction flask;

3. Add a small amount of hydrochloric acid catalyst (about 2~3 drops);

4. Stir it well, and then use the dispenser funnel to add a 5% sodium hydroxide solution and stir it well;

5. The reaction flask is placed in a wide-mouthed hot water bath made from hot water, heated to the boiling point and kept at this temperature for 30 minutes;

6. At the end of the reaction the reaction solution is cooled down to room temperature;

7. Appropriate amount of saturated sodium chloride solution is added and stirred well;

8. The organic phase is taken out of the upper layer and placed in a dried and weighed Drying bottle, plus a little dialysine coagulant, and add glass beads and mix well;

9. Seal the drying bottle and weigh, record the weight, and finally infrared spectroscopy analysis.

Experiment Note:

1. The laboratory must be kept clean, neat, bright and well ventilated, and each item must be cleaned at the end of each experiment, and useless items put into the trash can.

2. experiments in the operation of glass instruments, must pay attention to the operation process should be gently held and put, pay attention to prevent breakage.

3. Smoking is prohibited in the laboratory, prohibit walking around, experiments must wear good laboratory gloves, masks, goggles and other necessary protective equipment.

Experimental results:

After reaction, separation and drying, the ethyl cinnamate was obtained as a light yellow liquid with a net weight of 2.35 g.

Experimental conclusions:

Through the experiment, we learned the principle and conditions of esterification reaction, mastered the esterification reaction between different acids and alcohols, and familiarized ourselves with the method of preparation of ethyl cinnamate and its operation steps. At the same time, we also mastered the basic operating skills of organic synthesis experiments and general knowledge of laboratory safety. The experiment successfully synthesized ethyl cinnamate, and the experimental results are in line with the theoretical value.