Nitration of Naphthalene
Purpose of experiment:
The purpose of this experiment was to nitrate naphthalene with nitronium ion, which is formed at low concentration from a reaction of nitric acid and sulfuric acid. Naphthalene is a house product used... The major product from the reaction is the kinetic product, the one that forms the more stable cabocation intermediate.
Method and procedure:
Into a 5-ml conical vial, 1.0ml of mixed 1:1 sulfuric acid and nitric acid was added. 0.50g of finely divided naphthalene was added in small portions to the solution while stirring after each addition, and cooling to keep the temperature around 45-50°C. The reaction mixture was then stirred in a 60°C water bath for 20minutes after the addition of naphthalene.
When the reaction cooled to room temperature, the solution was transferred to a beaker containing 25ml of ice-cold was with stirring. Yellow crystals are allowed to form, and then the liquid content is removed with filter-tip pipet. The solid was then boiled with 10ml of fresh water for 10minutes.
The mixture was cooled in ice and the product was collected by vacuum filteration. 0.1 of the crude product was then recrystallized for 5minutes with 5ml of hexane under reflux. The hot solution was filtered using a preheated filtering paper. Crystallization occurred, and then the product was collect by vacuum filteration. Th product was dried and the melting and mass were measured of the product, nitronaphthalene.