6-Amino coumarins and maleic anhydride were refluxed in gl acetic acid to y
ield N-6-coumarinyl maleimides as a dienophiles. These dienophiles, anthrac
ene and aluminium chloride in dichloromethane at room temp yielded 9,10-dih
ydro anthracene-9,10-endo-N-6'-coumarinyl maleimides (5a-d).