Acetanilide vs. Aniline

Attribute	Acetanilide	Aniline
Synonyms	Acetanilid, N-phenylacetamide	Aminobenzene, Phenylamine
Chemical Formula	C8H9NO	C6H7N
Molecular Weight	135.17 g/mol	93.13 g/mol
Appearance	White crystalline solid	Colorless to pale yellow liquid
Odor	Odorless	Weak, fishy odor
Solubility	Soluble in hot water, ethanol, and ether	Soluble in ethanol, ether, and chloroform
Boiling Point	304 °C (579 °F)	184 °C (363 °F)
Melting Point	113 °C (235 °F)	-6 °C (21 °F)
Uses	Used in the production of dyes, pharmaceuticals, and rubber accelerators	Used as a precursor in the production of various chemicals, including dyes and pharmaceuticals

Introduction

Acetanilide and Aniline are both organic compounds that belong to the class of aromatic amines. While they share some similarities in terms of their chemical structure and applications, they also possess distinct attributes that set them apart. In this article, we will explore the various characteristics of Acetanilide and Aniline, including their physical properties, chemical reactivity, and common uses.

Physical Properties

Acetanilide, also known as N-phenylacetamide, appears as a white crystalline solid with a melting point of approximately 114°C. It is sparingly soluble in water but dissolves readily in organic solvents such as ethanol and acetone. On the other hand, Aniline, also called aminobenzene, is a colorless to pale yellow liquid with a distinct odor. It has a lower melting point of -6°C and is highly soluble in water, alcohol, and ether.

Chemical Structure

Both Acetanilide and Aniline consist of a benzene ring attached to an amino group. However, Acetanilide contains an additional acetyl group (-COCH3) attached to the amino group, while Aniline lacks this acetyl group. This structural difference gives rise to variations in their chemical properties and reactivity.

Chemical Reactivity

Acetanilide exhibits relatively low reactivity due to the presence of the acetyl group, which acts as an electron-withdrawing group. This group reduces the electron density on the amino group, making it less susceptible to nucleophilic attacks. On the other hand, Aniline is more reactive as it lacks the acetyl group, allowing the amino group to readily participate in various chemical reactions. Aniline can undergo electrophilic aromatic substitution reactions, such as nitration and halogenation, more easily than Acetanilide.

Acid-Base Properties

Both Acetanilide and Aniline can act as weak bases due to the presence of the amino group. However, Aniline is a stronger base compared to Acetanilide. This difference arises from the electron-donating nature of the amino group in Aniline, which enhances its ability to accept protons. Acetanilide, on the other hand, exhibits weaker basicity due to the electron-withdrawing effect of the acetyl group.

Common Uses

Acetanilide finds applications in various fields, including the pharmaceutical industry. It has been used historically as an analgesic and antipyretic agent, although its use has declined due to potential toxicity concerns. Acetanilide is also utilized in the synthesis of dyes, rubber accelerators, and pesticides. Aniline, on the other hand, has a wide range of applications. It serves as a precursor for the production of numerous dyes, including synthetic indigo. Aniline is also used in the manufacturing of rubber, pharmaceuticals, and various chemicals.

Toxicity

While both Acetanilide and Aniline possess potential health hazards, Aniline is considered more toxic than Acetanilide. Aniline can be absorbed through the skin, inhalation, or ingestion, and prolonged exposure can lead to adverse effects on the blood, liver, and kidneys. Acetanilide, although less toxic, can still cause skin irritation and may have harmful effects on the blood and liver if consumed in large quantities.

Conclusion

In conclusion, Acetanilide and Aniline are two aromatic amines with distinct attributes. Acetanilide is a white crystalline solid with lower reactivity and weaker basicity due to the presence of an acetyl group. Aniline, on the other hand, is a colorless to pale yellow liquid with higher reactivity and stronger basicity. Both compounds find applications in various industries, although Aniline has a wider range of uses. It is important to handle these compounds with caution due to their potential toxicity. Understanding the differences between Acetanilide and Aniline allows for their appropriate utilization in different chemical processes and applications.