Acetanilide

Acetanilide, with the molecular formula C8H9NO, has a molecular weight of 135.16 g/mol. 

Acetanilide is also known as N-phenylacetamide, N-phenylethanamide, and methanol.

It is a fact that the compound acetanilide was accidentally prepared. Carl Duisberg, a scientist performing the synthesis of phenacetin from nitrophenol, somehow discovered acetanilide in 1886. 

Acetanilide is prepared when we heat acetic anhydride or glacial acetic acid which reacts with aniline and zinc dust being present in the surrounding medium to form acetanilide and acetic acid.

We use zinc dust to prevent oxidation in the reaction.

C6H5NH2 + CH3COOOCH3 → C6H5-NH-COCH3 +  CH3COOH

Acetanilide is an white, odourless, solid compound. This is prepared by synthesis of organic compounds in chemistry labs. It is prepared by acetylation of aniline.

First of all the requirements are

1. A 100ml volume round bottom flask
2. a wire gauze
3. a tripod stand
4. Burner
5. Clamp
6. Reflux condenser
7. Stirrer
8. Filter paper
9. Beaker
10. Pipette
11. Electronic balance
12. Iron stand
13. Measuring cylinder
14. IAniline (20 ml)
15. Acetic anhydride
16. Glacial acetic acid mixture (40 ml)
17. Zinc dust. 

When heat is supplied to acetic anhydride,it reacts with aniline,while zinc dust being present in the atmosphere (Zinc dust helps to prevent oxidation in the reaction),glacial acetic acid and acetanilide are formed. So ,formed acetanilide is impure and purification is required for which we have to recrystallize the acetanilide. We use zinc dust to prevent oxidation of aniline in the reaction. Acetanilide is also known as N-phenylacetamide, N-phenylethanamide and methanol.

Procedure

First and foremst, clean the apparatus to use water before commencing the experiment. Then, add 40 ml of acetic anhydride mixture,glacial acetic acid and 20 ml aniline into a round bottom flask of capacity 100 ml. Stir the mixture formed in the reaction continuously. After that, put in zinc dust in the flask to prevent oxidation in the reaction. Then a round bottom flask is fixed on the gas burner to heat the mixture formed in the reaction which is in the flask using a a tripod stand, a wire gauze, and sand bath. Heat continuously for 30-40 minutes. Stir the mixture thoroughly. Thereafter, pour the mixture formed in the reaction from the round bottom flask into a beaker filled with ice-cold water. Keep stirring the mixture. Once all acetanilide is precipitated below, filter the mixture formed in the reaction. since the obtained acetanilide crystals are crude or impure in nature,a recrystallisation process must be carried out for purification.

For recrystallisation

Dissolve the crude acetanilide in 50 ml of water in a beaker and a stirrer. Add a minute amount of ethanol to it. Heat this solution till it’s clear while stirring continuously. After that, we will get a solution. Then, cool down the solution and also filter it. Let the crystals dry. If we want to get more pure crystals of acetanilide, we will have to perform the recrystallisation process twice.

Precaution while preparing:-

Aniline is found to be a type of toxic compound so it is to be handled with care. It is bad for your health to inhale its fumes. If we measure the weight and melting point of the compound, first we have to dry the compound because it adds extra weight and lower the temperature which gives error in measurement. Get continuously stirring the mixture formed in the reaction during performing experiments to mix the solution properly. Before adding the mixture into cold water we have to heat properly.

These precautions are very important while performing experiments to avoid any accident so please be careful students.

In aniline, aromatic amines are known as arylamines. Aromatic amines are said to be aniline or aniline derivatives. When on the benzene ring a substituent is present, then the position of the substituent is represented by the suitable numeral and the carbon atom of aryl groups to which the amino group (-NH₂) is attached is provided the lower number.

Acetic acid, also known as ethanoic acid, has the chemical formula CH3COOH and has the molecular weight 60g/mol. 

Acetanilide, which is a type of drug, is used in pharmaceuticals. It is a synthetic organic compound that was discovered in 1886 by Carl Duisberg.

This drug is used for relieving pain (as a painkiller), and as an alternative like aspirin for headaches or menstrual cramps.

Acetanilide has various applications. It is used in the textile industry to manufacture coloured dyes for fabrics and textiles. Acetanilide is also used in the inhibitor of hydrogen peroxide decomposition. It is used in the manufacture of 4-acetamidobenzenesulfonyl chloride, an important intermediate for the manufacture of the sulfa drugs. However, it is unacceptable or toxic for the kidneys and liver and can cause kidney damage.

It was established in 1948 that acetanilide was mostly used for paracetamol for the human body, and it is paracetamol that was responsible for the analgesic and antipyretic properties. Paracetamol has since been replaced by acetanilide usage because it induces blood disorders .

Conclusion

Acetanilide, which is a mixture of acetic acid and aniline, has many uses such as in drugs and medicines, but it has some side effects as well.Thus, its usage is limited in pharmaceuticals. It has many applications in the textile industry.