Question

Phenol reacts with $PC{l_5}$ , the main product is:
A.
B.
C.
D. None of these

Answer 1

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.