P-Phenetidine

P-Phenetidine, also known as para-phenetidine or 4-ethoxyaniline, is an organic compound that belongs to the class of aniline derivatives. It is a colorless to slightly yellow liquid that is soluble in water and most organic solvents. P-Phenetidine is primarily used in the synthesis of dyes, pharmaceuticals, and as an intermediate in the production of other chemical compounds.

Chemical Properties

P-Phenetidine has the chemical formula C8H11NO and a molecular weight of 137.18 g/mol. It is structurally characterized by an aniline moiety where the amino group is attached to the para position of the benzene ring, and an ethoxy group is bonded to the same ring. This structure confers to p-phenetidine both hydrophilic and lipophilic properties, making it a versatile intermediate in organic synthesis.

Synthesis

P-Phenetidine can be synthesized through the ethoxylation of aniline, where aniline reacts with ethyl bromide or ethyl chloride in the presence of a base, typically potassium hydroxide, to yield p-phenetidine. This reaction is an example of nucleophilic aromatic substitution.

Applications

Pharmaceuticals

One of the primary applications of p-phenetidine is in the pharmaceutical industry, where it is used as an intermediate in the synthesis of analgesic and antipyretic drugs such as acetaminophen (paracetamol). The conversion of p-phenetidine to acetaminophen involves acetylation of the amino group.

Dyes

P-Phenetidine is also utilized in the production of azo dyes. It acts as a coupling agent in the synthesis of various azo compounds, which are widely used as coloring agents in textiles, food, and cosmetics.

Safety and Toxicology

P-Phenetidine is considered to be a hazardous substance due to its potential toxic effects. It is a skin and eye irritant and may cause allergic skin reactions. Inhalation or ingestion of p-phenetidine can lead to methemoglobinemia, a condition where a significant amount of hemoglobin is converted to methemoglobin, reducing the blood's ability to carry oxygen. Proper handling and protective equipment are recommended when working with p-phenetidine.

Regulation

Due to its potential health risks, the use and handling of p-phenetidine are regulated under various chemical safety standards worldwide. In the workplace, exposure limits for p-phenetidine have been established to protect workers from its harmful effects.

See Also

• Aniline
• Acetaminophen
• Azo dye
• Methemoglobinemia