Lab 1 Nitration Of Naphthalene
Lab report # 1
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. The percent yield from the experiment was 54.4% of the product, and the melting point of the possible results were 59 °C for 1-nitronaphthalene, and 78°C for 2-nitronaphthalene.
Polynuclear aromatic hydrocarbons such as naphthalene can be nitrated by the same methods as benzene derivatives, including the well-known “mixed acid” method that utilizes a mixture of nitric acid and sulfuric acid. The electrophile is the nitronium ion, NO2+, which is formed at low concentration by a reaction of the two acids. The mononitration of naphthalene could lead to either one of two products, 1-nitronaphthalene or 2-nitronaphthalene. 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.
Sulfuric acid and nitric acid can cause very serious burns, and they react violently with water and other chemicals. Nitric acid produces toxic nitrogen dioxide fumes during the reaction. Use gloves and a hood, avoid contact with the acids, and do not breathe their vapors. The nitro naphthalene is a suspected carcinogen; avoid contact. The mixture of hexanes is very flammable; keep flames away.
Into a 5-ml conical vial, 1.0 ml of mixed 1:1 sulfuric acid and nitric acid was added. Approximately, 0.610 g 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 20 mL of
References: Multiscale operational organic chemistry, by John W. Lehman, custom edition.