A mixture of 2.55 g of indole-4-carboxaldehyde and 4 ml of 50% sodium hydroxide solution was added with stirring under an inert atmosphere to a solution of 3.5 g of the product of Step B in 40 ml of ethanol and after stirring for 24 hours, the mixture was diluted with water and extracted with ethyl acetate. The organic phase was washed with water and the wash water was reextracted with an 8-2 chloroform-methanol mixture. The extract was washed with water and aqueous sodium chloride solution and the combined organic phases were dried over a deshydrant and were evaporated to dryness. The residue was chromatographed over silica gel and eluted with a 9-1 ethyl acetate-triethylamine mixture to obtain 4.3 g of 1-[4-{-2-(1,1-dimethylamino)-ethoxy}-phenyl]-3-[1H-indol-4-yl]-2-propen-1-one (E) melting at ≃162° C.
