To synthesize 1,2,3,4-tetraphenylnaphthalene through a two-step synthesis. The aldol condensation reaction between benzil and dibenzyl ketone forms 2,3,4,5-tetraphenylcyclopentadienone, which then reacts with a benzene formed by anthranilic acid and isoamyl nitrate in order to yield 1,2,3,4-tetraphenylnaphthalene.
Reaction Equation A:
Synthesis of 2,3,4,5-tetraphenylcyclopentadienone:
A solution of 4 capsules potassium hydroxide (0.5g) and 5mL anhydrous ethanol was prepared and warmed in a 25mL beaker. Benzil (2.1542g) , dibenzyl ketone (1.9599g) , 15mL anhydrous methanol, and a boiling stone was placed into a 50mL round-bottomed flask and fit with a reflux condenser and then gently heated. The temperature was raise nearly to the boiling point, and the solution of potassium hydroxide and anhydrous ethanol was added in two portions through the top of the condenser. The mixture was heated under reflux for an additional 15 minutes after the foaming subsided. The mixture was then allowed to cool to room temperature and then put into an ice water bath. Afterwards, the crystals were collected via suction filtration and rinsed with three 5-mL portions of cold 95% ethanol to yield 2,3,4,5-tetraphenylcyclopentadienone in an 81.2% yield as a dark purple crystalline solid: mp 218-220°C, (lit3 mp 217-220°C)
Reaction Equation B:
Synthesis of 1,2,3,4-tetraphenylnaphthalene:
2,3,4,5-tetraphenylcyclopentadienone and 1,2-dimethoxyethane were added to a 100mL round-bottomed clask which was equipped with a Claisen adapter and reflux condenser and warmed using the thermowell at about 30%. Anthranilic acid and 1,2-dimethoxyethane were dissolved together and placed into the addition funnel. Isoamyl nitrite was added to a test tube containing 1,2-dimethoxyethane. The two solutions were added slowly over 45 minutes under reflux. After completion of the addition, the reaction was warmed under reflux for an additional 15 minutes.