Question

show how to carry out the transformation of benzene to bromobenzene by going through a diazonium intermediate. at each step, either select the appropriate reagents or draw the correct product.

Answer 1

To transform benzene to bromobenzene, one must first convert benzene to aniline, then to a diazonium salt, and finally react with bromide to obtain bromobenzene.

Step-by-step explanation:

The transformation of benzene to bromobenzene using a diazonium intermediate involves several steps. Firstly, benzene reacts with nitric acid and sulfuric acid to form nitrobenzene, which is then reduced to aniline. Aniline is diazotized using sodium nitrite and hydrochloric acid at low temperatures, forming benzene diazonium chloride. This intermediate is then treated with a source of bromide ions, such as HBr, to obtain bromobenzene. Additionally, the three isomers of dibromobenzene are ortho, meta, and para, showing the different substitution patterns on an aromatic ring.

Three isomers of a six-membered aromatic ring compound substituted with two bromines, also known as dibromobenzene, are ortho-dibromobenzene (two bromines adjacent), meta-dibromobenzene (two bromines with one carbon apart), and para-dibromobenzene (two bromines with two carbons apart). These isomers demonstrate the concept of substitution reactions in aromatic compounds, which typically are preferable over addition reactions, maintaining the aromatic stability of the benzene ring.