To an addition funnel, add 12ml of ice-cold conc. sulfuric acid and 10ml of ice-cold conc. nitric acid, to a beaker, add 12.8g of naphthalene and heat the beaker in 45°C. The acid should be added with stirring over 10 minutes. Then the mixture is stirred at 60°C for 45 minutes and poured to 300ml of cold saturated sodium carbonate solution. The mixture is filtered, washed with some water and dried. Recrystallize in hot ethanol.
Pouring the mixture to the sodium carbonate solution
The crude product