Question

Draw the diazonium cation formed when cytosine reacts with NaNO2 in the presence of HCl

Answer 1

Concepts and reason

Diazonium salt: It is an intermediate in the Sandmeyer reaction, generally used for the conversion aromatic amine into aryl halides. Initially aniline or aryl amines were treated with nitrous acid, which was prepared in-situ by the reaction of sodium nitrite with monoprotic acid (HX), resulted in production of diazonium salt an intermediate, which intern reacts with halide ion to produce aryl halide.

Fundamentals

Diazonium salt preparation scheme is shown below:

This diazonium salt further reacts with copper halide to give aryl halide;this complete process is called as Sandmeyerreaction.

Given reaction condition is drawn below:

It is clear from the above reaction condition that the reaction represents the diazonium salt preparation.

Mechanism of the above preparation is drawn below:

Final product in the given reaction is diazonium salt.

Therefore,the final diazonium product of the reaction is shown below:

Ans:

Diazonium cation formed in the reaction of cytosine with ${\bf{NaN}}{{\bf{O}}_{\bf{2}}}$ and HCl is shown below: