To a solution of 5-fluoro-3-formyl-1-naphthalen-1-ylmethyl-1H-indole-2-carboxylic acid ethyl ester (from Example 76.1., 0.60 g) in MeOH (5.0 ml), AcOH (0.92 ml), tetrahydrofuran (2.0 ml) and methyl amine (2 M in THF, 3.2 ml) was added portion wise Na(CN)BH3 (202 mg) and stirring was continued at 22° C. for 3 h. The mixture was evaporated and the residue partitioned between 1 N aqueous HCl and dichlormethane. The pH of the aqueous layer was adjusted to 11 using NaOH, extracted with dichloromethane, dried and evaporated to give 5-fluoro-3-methylaminomethyl-1-naphthalen-1-ylmethyl-1H-indole-2-carboxylic acid ethyl ester as a colorless oil. MS: 391.3 ([M+H]+).
