What ring of phenyl benzoate would undergo nitration more easily?

Answer 1

Nitration occurs through electrophilic addition of aromatic rings by breaking one of its aromatic bonds in order to attack the nitogen. The ring with more electron density will be more likely to add NO2 groups in its meta position (the only position if another group is already attached). When electrophillic addition occurs, the benzene ring would have to unfavorably break its stable aromaticity to attack. However, the phenyl oxygen can donate its electrons to the benzene ring, thus enriching it with electron density and stabilizing the positive charge.

The carbonyl group does nothing to stabilize the other benzene ring during its electrophilic addition. In fact, the carbonyl group may as well have the opposite effect: the resonance structure of a single bonded carbon to its oxygen pulls electrons away from the benzene ring through inductive effect.