Deduce a positive structure for the compound $\left(\mathrm{A}\right)$ of the formula ${\mathrm{C}}_8{\mathrm{H}}_9\mathrm{NO}$ which is insoluble in dilute acid and base. On treatment with ${\mathrm{KMnO}}_4$ in ${\mathrm{H}}_2{\mathrm{SO}}_4,$, it gives compound $\mathrm{B},$ which is free of nitrogen, soluble in aqueous ${\mathrm{NaHCO}}_3$ and gives only one mononitro substitution product.

Arrange the following compounds in the decreasing order of coupling with benzenediazonium chloride.

What should be the final product in the following reaction?

When a $2°$ aromatic amine hydrochloride is heated, it leads to the formation of $1°$ amine hydrochloride. The reaction is known as

For diazonium ions, the order of reactivity towards diazocoupling with phenol in the presence of dil. $\mathrm{NaOH}$ is:

Product of this reaction is: