In present work I investigated the Diels–Alder reaction of 3-benzoylamino-6-(2-thienyl)-2H-pyran-2-one with maleic anhydride under different reaction conditions.
Reaction under reflux conditions yielded bicyclic double adduct (substituted bicyclo[2.2.2]oct-7-ene). Microwave irradiation led to formation of the same bicyclic double adduct and an unknown by-product, which I later identified as aromatic product (isobenzofuran derivative) and found appropriate microwave conditions for its formation as the only product. I also optimized reaction conditions for synthesis of aromatic product under conventional conditions with addition of activated charcoal. Microwave synthesis of aromatic product was much faster, environmentally friendly, product was cleaner and yield was higher compared to conventional synthesis.
During research I also noticed and further investigated degradation process of bicyclic double adducts on TLC silicagel plates. Silicagel could be potentially used as catalyst for hydrolysis of anhydride moiety in bicyclic double adducts.
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