${CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{Br} \xrightarrow[\Delta]{\mathrm{KOH}_{(a k)}} \mathrm{A} \xrightarrow{\mathrm{HBr}} \mathrm{B} \xrightarrow[\mathrm{KOH}_{(a) i}]{\Delta} \mathrm{C}$
${C_2}{H_5}OH + SOC{l_2}\xrightarrow{{{\text{Pyridine}}}}{C_2}{H_5}Cl + S{O_2} + HCl$