Identify the major product R formed in the following reaction...

Reaction of phenylacetic acid with ammonia followed by heating yields phenylacetamide.

$\mathrm{C_6H_5CH_2COOH} \xrightarrow[\Delta]{\mathrm{NH_3}} \mathrm{C_6H_5CH_2CONH_2}$ (P)

Phenylacetamide undergoes Hoffmann bromamide degradation on treatment with $\mathrm{Br_2}$ and $\mathrm{KOH}$ to form benzylamine.

$\mathrm{C_6H_5CH_2CONH_2} \xrightarrow{\mathrm{Br_2/KOH}} \mathrm{C_6H_5CH_2NH_2}$ (Q)

Benzylamine, being a primary aliphatic amine, reacts with nitrous acid (generated in situ from $\mathrm{NaNO_2}$ and $\mathrm{HCl}$) to form an unstable diazonium salt. This salt decomposes to give a benzyl carbocation, which is trapped by water to form benzyl alcohol.

$\mathrm{C_6H_5CH_2NH_2} \xrightarrow{\mathrm{NaNO_2 + HCl}} [\mathrm{C_6H_5CH_2N_2^+Cl^-}] \xrightarrow{\mathrm{H_2O}} \mathrm{C_6H_5CH_2OH}$ (R)

Answer: $\mathrm{C_6H_5CH_2OH}$