Tetraphenylcyclopentadienone Reaction Lab Report

Experiment 3 comprised three reactions: formation of dimethyl tetraphenylphthalate, hexaphenylbenzene, and tetraphenylnaphthalene. All 3 reactions used tetraphenylcyclopentadienone as the diene to generate products with high aromatic stabilization.
The first reaction was the formation of dimethyl tetraphenylphthalate. A cloudy white solid was formed with 31.1% yield. In This reaction dimethyl acetylenedicarboxylate was used as the dienophile with a Carbonyl group as the electron-withdrawing group. A resonance stabilized aromatic ring was formed ( favored rection). The nitrobenzene was used to facilitate the by acting as a high boiling solvent, dissolving both reactants, and thereby driving the Diels-Alder reaction. Refluxing moved this reaction further, forming an intermediate. The violet solution turned beige when forming a six-membered ring by losing carbon monoxide. This loss made the overall reaction irreversible.

A white solid was formed as a product with 59.3% yield. In this reaction tetraphenylcyclopentadienone used as the diene, which was condensed with a highly reactive alkyne dienophile (diphenylacetylene). Heat was used to overcome the diene’s enhanced activation energy. The mixture turned dark brown indicated the loss of carbon monoxide, which made this reaction, overall, irreversible. The result was formation of a high yield hexaphenylbenzene which is more stable than the first product, The Reason is that the delocalized electrons in the rings give more stability to hexaphenylbenzene as compared to the dimethyl