Question

To convert m-ethylaniline to m-ethylfluorobenzene, it should be treated with nitrous acid followed by _____________.

Answer 1

Answer:

$NaBF_4$

Explanation:

In this reaction, we must exchange the amino group ($NH_2$) for a fluorine atom ($F$). Also, the first step in this reaction is the addition of nitrous acid.

We must remember that the amino group in the presence of nitrous acid produces a diazonium salt. The $N_2$ group is a very good leaving group and many benzene derivatives can be produced from this intermediate (see figure 1).

If what we want is to bond a fluorine atom we must use $NaBF_4$ to be able to produce m-ethylfluorobenzene (see figure 2).

I hope it helps!