A mixture of 9-amino-3-[2-(3-azabicyclo[3.2.2]non-3-yl)ethyl]-1,2,3,4-tetrahydro-8-methyl-5H-benzopyrano[3,4-c]pyridin-5-one (2.5 g, 0.007 moles), potassium carbonate (2.4 g, 0.017 moles), and benzoyl chloride (1.0 ml, 0.009 moles) is stirred in chloroform (50 ml) at room temperature. After 24 hours the mixture is poured into ice water. The layers are separated, and the aqueous phase is extracted with chloroform (2×60 ml). The combined organic extracts are washed with brine and dried (magnesium sulfate). The solvent is removed under reduced pressure to leave a syrup, which crystallized from ethyl acetate. Recrystallization gave the product (1.3 g), mp 174°-176° C.
