The reaction of 4-(3-indolyl)butyric acid (I) with 4-phenyl-3,4-dehydropiperidine (II) by means of carbonyldiimidazole (A) in THF gives 3-[4-oxo-4-(4-phenyl-3,4-dehydro-1-piperidyl)butyl]indole (III), which is reduced with LiAlH4 in THF.

By condensation of (II) with 3-(4chlorobutyl)indole (IV) in acetonitrile. Other compounds with Br, I or tosyloxy substituents instead of Cl can also be used in the above mentioned synthesis.

The reaction of 4-(3-indolyl)butyric acid (I) with 4-phenyl-3,4-dehydropiperidine (II) by means of carbonyldiimidazole (A) in THF gives 3-[4-oxo-4-(4-phenyl-3,4-dehydro-1-piperidyl)butyl]indole (III), which is reduced with LiAlH4 in THF.

By condensation of (II) with 3-(4chlorobutyl)indole (IV) in acetonitrile. Other compounds with Br, I or tosyloxy substituents instead of Cl can also be used in the above mentioned synthesis.