Tandem Migration–Carboalkoxylation of o-Isocyanophenyl Acetals Leading to Benzoxazoles
摘要:
An efficient approach to benzoxazoles via tandem migration carboalkoxylation of o-isocyanophenyl acetals has been developed. Both a Lewis acid and base are essential for this reaction, and the BF3 center dot OEt2/2,4,6-collidine combination is the best choice for cooperative transformation.
New acridine derivatives have been prepared via Ullman condensation involving benzoxazole (5) and 2-bromo-benzoic acid. Linear products were obtained. The structure of oxazolo[4,5-b]acridine was determined by NMR spectroscopy.