Question

Hypothesis 1 For the alkylation of sodium saccharide, what will be the major product, O-alkylation or N-alkylation? Rationalize the choice.  

Hypothesis 2 For the nitration of benzoic acid, predict whether mono-nitration or di-nitration will dominate and chemically explain the choice. Note that excess nitric and sulfuric acids are being used, so “limiting reagent” will NOT be the answer.  

Answer 1

N-alkylation will be the major product as the lone pair on the nitrogen is more nucleophilic which is because of the lower electronegativity of N as compared to O.  

The -COOH group on the benzoic acid is an electron withdrawing group. Hence, it deactivates the ring by pulling electron density from the ring. On mononitration, the ring will deactivated further as the ring is now having two electron withdrawing groups - -COOH and -NO₂. Hence, di-nitration is unlikely to happen on the ring and mono-nitration will dominate.