The condensation of 6-methoxy-2-tetralone (I) with pyrrolidine (II) in methanol gives the enamine (III), which is treated with 2-bromoacetonitrile (IV) to yield the pyrrolidinium salt (V). The hydrolysis of (V) with acetic acid in dichloromethane/methanol affords 2-(2-oxo-1,2,3,4-tetrahydronaphthalen-1-yl)acetonitrile (VI), which is cyclized with ammonium acetate and NaBH3CN in refluxing methanol to provide the benzoindole derivative (VII). The condensation of (VII) with trans-4-(phenylsulfonamidomethyl)cyclohexanecarboxylic acid (VIII) by means of HBTU and DIEA in DMF gives the corresponding amide (IX), which is reduced with LiAlH4 in THF to yield the secondary amine (X). Finally, this compound is demethylated by means of BBr3 in dichloromethane.

Enamine (III), prepared from beta-tetralone (I) by condensation with pyrrolidine (II) in refluxing benzene, was alkylated with bromoacetonitrile to provide, after hydrolytic treatment, keto nitrile (IV). Reductive amination of (IV) with ammonium acetate and NaBH3CN in MeOH furnished the benzo[e]indole tricyclic derivative (V), isolated as the hydrochloride salt. Coupling of (V) with trans-4-[(benzenesulfonamido) methyl]cyclohexanecarboxylic acid (VI) using O-benzotriazol-1-yl-N,N,N?N?tetramethyluronium hexafluorophosphate (HBTU) gave amide (VII). This was finally reduced to the corresponding amine employing LiAlH4 in THF.