Question

Among the following sets of reactions which one produces anisole ?
a.) $C{H_3}CHO$; RMgX
b.) ${C_6}{H_5}OH$; NaOH, $C{H_3}I$
c.) ${C_6}{H_5}OH$; neutral $FeC{l_3}$
d.) ${C_6}{H_5} - C{H_3}$; $C{H_3}COCl$; $AlC{l_3}$

Answer 1

The anisole has IUPAC name methoxy benzene. This is a colourless liquid. It requires the suitable aromatic ring along with alkyl halide for its preparation. A strong base is required to initiate the reaction. So, the option having all these components will be the correct one.

Complete answer:
First, we need to know what is anisole. Only then we can tell what are the reagents that are required to prepare anisole.
The anisole is the benzene ring substituted by methoxy group.
So, now let us see the options given to us one by one.
The first option is $C{H_3}CHO$and RMgX. This combination does not contain phenol rings. So, this option is incorrect.
The second option is ${C_6}{H_5}OH$, NaOH and $C{H_3}I$. Let us see the reaction.
${C_6}{H_5}OH + NaOH \to {C_6}{H_5}ONa\xrightarrow{{C{H_3}I}}{C_6}{H_5}OC{H_3}$
This is nucleophilic substitution reaction. The phenol reacts with sodium hydroxide and give phenoxide ion which reacts with methyl to give anisole. This is correct answer.
The third option is ${C_6}{H_5}OH$ and neutral $FeC{l_3}$.
The ferric chloride is used for oxidation. Here, the ferric chloride will oxidise phenol to acid. So, this is not the correct combination of reagents.
The fourth option is ${C_6}{H_5} - C{H_3}$, $C{H_3}COCl$ and $AlC{l_3}$. These reagents are also not suitable for formation of anisole. So, the option d.) is also incorrect.

Thus, the correct answer is option b.).

Note:
The above reagents that have been used to prepare anisole i.e. the phenol, sodium hydroxide and methyl iodide; this is called as Williamson’s synthesis reaction. It is the mostly used method to prepare a large variety of ethers. The metal alkoxide replaces the halide from the alkyl halide.