Preparation of n-butyl acetate

1. INTRODUCTION
Husky esters are widely used in the chemical industry. N-butyl acetate has a pleasant fruity aroma and is often used as a solvent, fragrance, etc. The preparation method is described in detail.

2. Preparation principle
Under the action of catalyst, acetic acid and n-butanol are esterified to form n-butyl acetate. The chemical reaction equation is as follows:
\ (CH_ {3} COOH + C_ {4} H_ {9} OH\ underset {\ Delta} {\ overset {catalyst} {\ rightleftharpoons}} CH_ {3} COOC_ {4} H_ {9} + H_ {2} O\)

III. Experimental materials and instruments
1. ** Materials **: acetic acid, n-butanol, concentrated sulfuric acid (as catalyst), saturated sodium carbonate solution, saturated sodium chloride solution, anhydrous magnesium sulfate (desiccant).
2. ** Instrument **: round bottom flask, reflux condenser, water separator, distillation device (distillation flask, thermometer, straight condenser, connecting tube, conical bottle), liquid separation funnel, electronic balance, measuring cylinder, etc.

4. Experimental steps
1. ** Esterification reaction **
- In the round bottom flask, weigh an appropriate amount of n-butanol with an electronic balance, measure a certain volume of acetic acid with a measuring cylinder, and then carefully add a few drops of concentrated sulfuric acid, shake well.
- Connect the round bottom flask to the reflux condenser and water separator to ensure that the device is tight and does not leak air.
- Heat on low heat to slowly reflux the reaction liquid. During the reaction, observe the change of water level in the water separator. When the water level in the water separator does not rise and the upper organic phase does not increase, it indicates that the reaction is basically completed. This process takes about [X] hours.
2. ** Product separation and purification **
- After the reaction liquid cools, pour it into the separation funnel. Wash with saturated sodium carbonate solution first, shake, let stand and stratify, and separate the lower aqueous phase. The purpose of this step is to neutralize the unreacted acetic acid and reduce the solubility of n-butyl acetate.
- Wash the organic phase with saturated sodium chloride solution again, and also shake, let stand, and separate to remove the residual sodium carbonate.
- Transfer the organic phase to a dry conical flask, add an appropriate amount of anhydrous magnesium sulfate, shake, and let stand for a period of time to remove trace moisture.
3. ** Distillation and Refinement **
- Filter the dried organic phase into the distillation flask and connect the distillation device.
- Heat the distillation to collect the fraction of [X] ° C - [X] ° C. This is the refined n-butyl acetate.

5. Precautions
1. Concentrated sulfuric acid should be added slowly and shaken while adding to prevent local overheating.
2. When heating, a low fire is required to avoid too violent reaction and at the same time prevent the carbonization of organic matter.
3. When separating the liquid, it is necessary to correctly distinguish the upper and lower layers of liquid to avoid product loss.
4. The drying process should be sufficient to ensure that trace moisture is removed, otherwise it will affect the distillation effect and product purity.

6. Conclusion
Through the above steps, n-butyl acetate can be prepared. The preparation process requires rigorous operation and attention to detail in order to obtain a product with higher yield and purity.