Increasing Order of Reactivity towards Electrophilic Aromatic Substitution Reaction

Electrophilic aromatic substitution (EAS) reactions involve the substitution of an electrophile into an aromatic ring. The reactivity of different compounds towards EAS reactions depends on various factors such as the presence of electron-donating or electron-withdrawing groups, resonance effects, and steric hindrance. To determine the correct increasing order of reactivity towards EAS reactions for the given compounds, we need to analyze these factors.

Compound A: Benzene

Benzene is a highly reactive compound towards EAS reactions. It has a delocalized pi electron system, which provides stability to the aromatic ring. The high electron density in the benzene ring makes it highly susceptible to electrophilic attack.

Compound B: Toluene

Toluene is a derivative of benzene with a methyl group (-CH3) attached to the ring. The methyl group is electron-donating, which increases the electron density on the ring. This electron-donating effect makes toluene more reactive than benzene towards EAS reactions.

Compound C: Nitrobenzene

Nitrobenzene contains a nitro group (-NO2) attached to the benzene ring. The nitro group is strongly electron-withdrawing due to the presence of the electronegative nitrogen and oxygen atoms. This electron-withdrawing effect decreases the electron density on the ring, making nitrobenzene less reactive than benzene and toluene towards EAS reactions.

Compound D: Anisole

Anisole is a methoxybenzene derivative with a methoxy group (-OCH3) attached to the ring. The methoxy group is electron-donating, similar to the methyl group in toluene. Therefore, anisole is more reactive than nitrobenzene but less reactive than benzene and toluene towards EAS reactions.

Based on the above analysis, the correct increasing order of reactivity towards EAS reactions for the given compounds is:

Nitrobenzene < anisole="" />< toluene="" />< />

This order is determined by the electron-donating or electron-withdrawing nature of the substituents attached to the benzene ring. Electron-donating groups increase the electron density on the ring, making the compound more reactive towards EAS reactions. Conversely, electron-withdrawing groups decrease the electron density on the ring, reducing the reactivity towards EAS reactions.