A colourless substance ' A ' $\left(\mathrm{C}_6 \mathrm{H}_7 \mathrm{~N}\right)$ is sparingly soluble in water and gives a water soluble compound ' B ' on treating with mineral acid. On reacting with $\mathrm{CHCl}_3$ and alcoholic potash ' A ' produces an obnoxious smell due to the formation of compound ' C '. Reaction of ' A ' with benzenesulphonyl chloride gives compound ' D ' which is soluble in alkali. With $\mathrm{NaNO}_2$ and HCl , 'A' forms compound ' E ' which reacts with phenol in alkaline medium to give an orange dye ' $F$ '. Identify compounds ' $A$ ' to ' $F$ '.

Predict the reagent or the product in the following reaction sequence.