Hydrochloric Acid → 1-{2-[4-({[5-chloro-6-(hydroxymethyl)-3-pyridinyl]methyl}amino)-1-piperidinyl]ethyl}-7-fluoro-1,5-naphthyridin-2(1H)-one hydrochloride

To a solution of 1-{2-[4-({[5-chloro-6-(hydroxymethyl)-3-pyridinyl]methyl}amino)-1-piperidinyl]ethyl}-7-fluoro-1,5-naphthyridin-2(1H)-one (Example 1: 163.2 mg, 0.366 mmol) in Dichloromethane (2.5 ml) at 0° C. was added HCl (4M in 1,4-dioxane) (0.092 ml, 0.369 mmol). The reaction mixture was stirred at RT for 30 min, the solvent was evaporated under vacuum and the crude was dispersed in hexane/DCM. The precipitated solid was isolated by filtration under vacuum and washed with DCM and hexane. The obtained solid was dried overnight at 40° C. under vacuum to give 1-{2-[4-({[5-chloro-6-(hydroxymethyl)-3-pyridinyl]methyl}amino)-1-piperidinyl]ethyl}-7-fluoro-1,5-naphthyridin-2(1H)-one hydrochloride (137 mg, 0.281 mmol, 77% yield) as a white solid.