What product is formed from the reaction of p-methylphenol with benzenediazonium chloride?

Verified step by step guidance

1. Step 1: Recognize the type of reaction. This is an example of an electrophilic aromatic substitution reaction, specifically a diazo coupling reaction, where benzenediazonium chloride acts as an electrophile and p-methylphenol acts as a nucleophile.
2. Step 2: Identify the reactive site on p-methylphenol. The hydroxyl (-OH) group on the phenol ring is an activating group that increases electron density on the aromatic ring, especially at the ortho and para positions relative to the -OH group. Since the methyl group is already at the para position, the coupling will likely occur at the ortho position.
3. Step 3: Understand the mechanism. The diazonium ion (N≡N⁺) from benzenediazonium chloride attacks the electron-rich ortho position of p-methylphenol, forming a new bond between the aromatic ring of p-methylphenol and the diazonium group.
4. Step 4: Consider resonance stabilization. The resulting product will have conjugation between the aromatic ring and the azo (-N=N-) group, which stabilizes the molecule. This conjugation is responsible for the vibrant colors of azo compounds.
5. Step 5: Name the product. The final product is an azo compound, specifically 2-(p-methylphenylazo)-p-methylphenol, where the azo group (-N=N-) connects the p-methylphenol and the benzene ring from benzenediazonium chloride.

Key Concepts

Electrophilic Aromatic Substitution

Electrophilic aromatic substitution (EAS) is a fundamental reaction in organic chemistry where an electrophile replaces a hydrogen atom on an aromatic ring. In this context, benzenediazonium chloride acts as the electrophile, which can react with the electron-rich p-methylphenol, leading to the substitution of a hydrogen atom on the aromatic ring.

Aromatic Compounds

Aromatic compounds are a class of cyclic compounds characterized by their stable ring structure and delocalized π-electrons. p-Methylphenol, also known as p-cresol, is an aromatic compound that contains a hydroxyl group (-OH) and a methyl group (-CH3) attached to a benzene ring, influencing its reactivity in electrophilic substitution reactions.

Diazonium Salts

Diazonium salts are highly reactive intermediates in organic synthesis, formed by the reaction of primary aromatic amines with nitrous acid. Benzenediazonium chloride is a common diazonium salt that can participate in various coupling reactions, including those with aromatic compounds like p-methylphenol, resulting in the formation of azo compounds.