Question

Phenol reacts with $PC{l}_5$ , the main product is:
A.

B.

C.

D. None of these

Answer 1

Hint: We know that in general, phosphorus pentachloride can be used for preparing alkyl chlorides from alcohol.

Complete step by step answer:
Functional groups impart specific characteristics as it is evident from the name itself. Based on the functional groups, we can have different categories of compounds. Let’s have a look at some of them.
Alkanes are simple hydrocarbons made up of only carbon and hydrogen atoms with a general formula of $C_n{H}_{2n+2}$ where $n$ is an integer.
Alkyl groups: These are derived from alkanes by removing one hydrogen atom and are present as substituents. We generally represent them with $R-$ which has been derived from the alkane $RH$ .
Haloalkanes: These are also derived from alkanes by substituting hydrogen atom(s) with halogen(s). Halogens come under functional groups and are usually represented by $$X$$ . So, we can use $$RX$$ for haloalkanes. As it is evident that there is one alkyl group connected to halogen which gives rise to another name for these compounds to be alkyl halides.
Alcohols: In this category, the functional group is represented by $OH-$ . Here also, hydrogen atom(s) in alkanes are replaced and we get $ROH$ .
As we can see that all of these are inter-related this led us to devise methods for preparing one from another. It has been found that generally, alcohols reacting with $PC{l}_5$ give alkyl chlorides. We can write the involved reaction as follows:
$R-OH+PC{l}_5\to R-Cl+POC{l}_3+HCl$
However, when phenol in which the alcohol group is attached to the benzene ring, is treated with $PC{l}_5$, it is quite different because in phenol, the $C-O$ bond is much stronger. So, when phenol reacts with $PC{l}_5$, following reaction takes place:
$PhO-H+PC{l}_5\to PhO-PC{l}_4+HCl$
We can draw the structure for as follows:

Therefore, the correct option is option (D).

Note:
We have to keep in mind that even though the functional group is the same, alkyl alcohols and aryl alcohols react differently.