With stirring at a pressure of 2 bars, a solution of 2.3 g of the product from Step A in 40 ml of ethanol and 37.5 ml of tert-butyl-amine was heated at 120° C. for 24 hours. After dilution with 400 ml of water and 400 ml of ethyl acetate, the solution was alkalized with sodium hydroxide and saturated with potassium carbonate. The mixture was extracted with ethyl acetate and the crystals obtained were triturated with ether to obtain 2.3 g of N-[2-[2-[(1,1-dimethylethyl)amino]ethoxy]phenyl]-1H-indol-4-carboxamide melting at ≃148° C.
