Answer to Question #182222 in Organic Chemistry for Joel Kutai

Question

Analyse the effects of the monosubstituets-OH, -Cl, -NO₂ and -CH₃ on the benzene ring and predict how they direct an attacking species (such as NO₂⁺, CH₃⁺, Br₂ and SO₃) to either the 2, 3 or 4 positions on the ring during substitution. Include within this section, the names of the substituted benzene compounds, indicating how the name is based upon the functional group(s) present and the different positions on the benzene ring.

Answer 1

There are 2 types of substituents, donor type and accepting type. Donor type: OH, Cl, CH3. Accepting type: NO2, SO3H. Donor type substituents have a lone electrone pair, they donati it to the ring, and electrone density in positions 2 and 4 increase, so substitution undergoes in 2 and 4 positions. Accepting type take electrones from the ring, and the only possible position for substitution is 3.

For example: phenol reacting with NO2+ will form ortho-nitrophenol and para-nitrophenol. Nitrobenzene reacting with SO3 will form only metanitrobenzenesulfonic acid.