Preparation of Acetanilide

Introduction

Acetanilide is a compound that can be used both in industries and medical field. It’s basic properties make it useful in both industries. It is a white coloured organic, which helps in organic synthesis. There are other Acetanilide tests too, that are used in the field of chemistry, such as The Beilstein Test and Green Method.

What is Acetanilide?

Figure 1 − Structure of Acetanilide

Acetanilide is an important organic compound that is widely used in the field of the pharmaceutical industry. It is an odourless and white coloured compound that exists either solid or flaky form. It can be synthesized in the lab with the help of the preparation methodin pure form.

Aim

The experiment aims to produce a useful chemical compound named Acetanilide and to prepare it Aniline is used and with that compounds like Glacial Acetic acid orAcetic anhydride and Zinc dust.

Theory

In the laboratory, Acetanilide can be prepared from the Aniline. It makes the final product when it starts reacting with the Acetic AnhydrideorGacial Acetic acid and occurs in the presence of Zinc dust. The mixture is refluxed under the anhydrous condition and then the mixture is poured into ice cold water. It helps to get the Acetic anhydride precipitate. The crude precipitate of it then recrystallized to get the ultimate productin pure form.

Figure 2 − Chemical reaction to produce Acetanilide

The purpose of using the Zinc dust in the reaction is to prevent the oxidation of the Aniline. It enhances the medical importance of the compound and makes it useful as a febrifuge.

Acetanilide can be prepared by using acetylating Aniline with Acetic anhydride in the presence of concentrated hydrochloric acid. In the reaction, the Aniline is dissolved in Hydrochloric acid and then in this mixture Acetic anhydride will be added, and at the end, the whole mixture needs to be stirred well. The Sodium Acetate mixture needs to be poured into the water and as a result, Acetanilide is formed, which needs to be separated and recrystallized using Ethyl alcohol.

Material required

For this experiment, a few items will be required −

• Aniline

• Glacial Acetic acid

• Acetic anhydride

• Zinc dust

• Stirrer

• Bunsen Burner

• Filter paper

• Electronic balance

• Distilled water

• Round bottom flask

• Beaker

• Pipette

• Reflux condenser

• Funnel

Process

To get the Acetanilide, a few steps are mandatory to follow −

• Before starting the experiment, the apparatus should be cleaned properly with the help of distilled water.

• In a round bottom flask, 10 ml of aniline, 20 ml of Acetic anhydride, Zinc dust, and gGacial Acetic acid should be added.

• The reflux condenser needs to be fixed.

• Add heat to the mixture for 15-20 minutes in an oil bath.

• In a beaker filled with ice water, the mixture needs to be poured and then it needs continuous stirring.

• The mixture needs to be stirred very strongly so it can hydrolyze the excess of Acetic anhydride.

• Once the Acetanilide will be precipitated and then it needs to be collected and filtered properly to get it in its pure form. For the filter process, the Buchner funnel is used.

• The result that is produced in the reaction is the crude version of the Acetanilide. To get the pure form, crystallization should be done.

Crystallization

Crystallization is the process that helps to get the pure Acetanilide from the crude sample that is produced in the synthesis process. For that, the sample needs to be added to the beaker that contains 20 ml of water and then the heat should be added to the mixture.

Observation

• The colour of the crystal − Colourless

• Shape − It has the shape of a plate

• Melting point − 114°C

Result

The weight of acetanilide crystals, which are produced in that experiment, can be found out by measuring it.

Precaution

Some precautions are mandatory, such as −

• Avoid inhaling the fumes of Acetic anhydride.

• “cetanilide needs to be handled with care.

• Stirring and heating the mixture is very important.

Uses of Acetanilide

The main use of Acetanilide are −

• It is used in the photography.

• It can be used in the making of plates.

• It is useful in the treatment of high fever and headaches.

Conclusion

This compound is also known as the N-phenylacetamide, Acetanilide, and Acetanil. In ancient times, when the first time it was discovered, it was used to treat fever and headache. It was popular by the brand name or trade name of Antifebrin. It has an appearance of a leaf and the colour is completely white.

FAQs

1. What is the main properties of Acetanilide?

Acetanilide is an Amide in nature and these Amides are one kind of base that is very weak. Acetanilide is one kind of solid chemical that has an appearance just like a leaf and it is odourless. Its melting point is 113–115°C.

2. Is Acetanilide a strong base or weak acid?

Acetanilide is neither a strong base nor a weak acid. It shows the nature of a neutral compound in the mixture. As it is in the neutral condition, it neither reacts with any inorganic base or acid.

3. Is Acetanilide water soluble?

Acetanilide shows a different kind of nature in water, when the temperature differs. For example, Acetanilide is soluble when the water is boiling, but it became less soluble when it is at room temperature or dissolved in cold water.

4. What is the main use of acetanilide?

The main use of acetanilide is that it is used as a fever-reducing drug. Not only that, but it also helps to reduce pain and it can be used to treat headaches, cramps etc.