reaction of amines at equations

Question

Write a skeletal equation for the reaction of phenylamine with sodium nitrate (III) in water, and then show how this diazonium salt reacts with the naphan-2-ol ion in a coupling reaction.

Answer 1

Hello! So I think what is meant here is NaNO2 (sodium nitrite) reacting with phenylamine to form the diazonium salt. How this works is that, first the negatively charged oxygen of the nitrite anion takes a proton from water, making it into NO2H. That same oxygen then takes another proton from water, making it now a good leaving group. That same oxygen leaves as water and takes a pair of electrons with it, leaving NO behind with positive charge on the N. The N in the amine now attacks the N of the NO, making the phenyl-N-N=O intermediate. The O then takes two protons either from water or from rearrangement from within the intermediate, making it a good leaving group (H2O+). It leaves, leaving the diazonium ion phenyl-N(triple bond)N. Naphthan-2-o- a strong base, is then added to the mix. The O-minus attacks the carbon of the phenyl diazonium that is attached to the nitrogen, kicking out the N(triplebond)N nitrogen gas, a very stable leaving group. You are left with the phenyl-O-naphthyl coupling product. I hope this helps!

-Vincent