Benzyne Formation and the Diels-Alder Reaction Preparation of 1,2,3,4 Tetraphenylnaphthalene Aubree Edwards Purpose: 1,2,3,4-tetraphenylnaphthalene is prepared by first producing benzyne via the unstable diazonium salt. Then tetraphenylcyclopentadienone and benzyne undergo a diels-alder reaction to create 1,2,3,4-tetraphenylnaphthalene. Reactions: Procedure: The reaction mixture was created. Tetraphenylcyclopentadienone (0.1197g, 0.3113 mmol) a black solid powder, anthranilic acid ( 0.0482g, 0.3516 mmol) a yellowish sand, and 1,2-dimethoxyethane (1.2 ml) was added to a 5-ml conical vial. A spin vane was added and a water-jacked condenser was attached. Isopentyl nitrite (0.06ml, 0.045 mmol) was dissolved in 1,2-dimethoxyethane (0.50 ml) in a 3-ml conical vial and caped to prevent loss by evaporation. Running the reaction. The mixture in the 5-ml conical vial containing the tetraphenylcyclopentadienone and anthranilic acid was heated on an aluminum block to 140° C. Once the mixture started to boil the prepared mixture of isopentyl nitrite was added to the 5-ml conical vial through the top of the condenser using a pasture pipette. The solution continued to boil for 25 more minutes until a …show more content…
The crude tetraphenylnaphthalene in a 25-ml Erlenmeyer flask and dissolved in boiling isopropyl alcohol (12 ml). The solution was cooled to room temperature and further cooled in an ice bath for 30 minutes. Crystallization of colorless crystals occurred. The product was collect in a Hirsch funnel and washed with isopropyl alcohol. The solid was left to dry over the weekend. The following lab period the solid was weighed (0.0483 g) and percent yield was calculated (65.5%) with the limiting reagent being tetraphenylcyclopentadienone. The melting point was determined. The first melting point was 204-204.9 °C and the second melting point was 215.6-215.9°C. Finally, an infrared spectroscopy was obtained for the