Question

How can the transformation of benzene to cyanobenzene be carried out by going through a diazonium intermediate?

1) Select the appropriate reagents
2) Draw the correct product
3) Both A and B
4) None of the above

Answer 1

The transformation of benzene to cyanobenzene involves converting benzene to a diazonium salt and then substituting the diazonium group with a cyanide group using reagents such as copper(I) cyanide.

Step-by-step explanation:

The transformation of benzene to cyanobenzene through a diazonium intermediate involves a two-step process. First, benzene is converted into a diazonium salt, and then the diazonium group is replaced by a cyanide group.

1. Reagents: The appropriate reagents to convert benzene into diazonium salt are nitric acid (HNO3) and sulfuric acid (H2SO4) to form nitrobenzene, followed by reduction with iron filings and hydrochloric acid to aniline, and ultimately treatment with sodium nitrite (NaNO2) and hydrochloric acid to form the diazonium salt.
2. Diazonium Salt to Cyanobenzene: The cyanide group is then introduced by treating the diazonium salt with copper(I) cyanide (CuCN) to replace the diazonium group and form cyanobenzene, also known as benzonitrile.
3. Correct Product: The final product is cyanobenzene, which has a benzene ring with a cyano group (-CN) attached to it.

The correct answer to the given student question would be option 3: Both A and B.