An 18 mL-vial was charged with 2-[4-[[2-(3-Chlorophenyl)-6,7-dihydro-5H-cyclopenta[b]pyridin-4-yl]amino]phenyl]acetonitrile (12 mg, 0.033 mmol, synthesis of this compound was described in EXAMPLE 1). Concentrated H2SO4 (0.5 ml) was added at 0° C. The mixture was standing at room temperature for 6 hr. And then the mixture was added very slowly to NaHCO3 aq. at 0° C. The precipitate was collected and washed with water, dried. The product thus obtained was treated with 4N HCl in dioxane and the volatile material was removed under reduced pressure to give the desired product 2-[4-[[2-(3-chlorophenyl)-6,7-dihydro-5H-cyclopenta[b]pyridin-4-yl]amino]phenyl]acetamide as HCl salt (2.6 mg, 19% yield). MW=377.87. 1H NMR (CDCl3, 360 MHz) δ 7.83 (s, 1H), 7.69 (m, 1H), 7.18-7.30 (m, 7H), 5.77 (brs, 1H), 5.44 (brs, 2H), 3.58 (s, 2H), 3.08 (t, J=7.70 Hz, 2H), 2.83 (t, J=7.10 Hz, 2H), 2.21 (m, 2H).
