To 150 mg (0.45 mmol) 1-[2-(4-hydroxymethyl-phenyl)-ethyl]-4-(pyridin-2-ylmethoxy)-1H-pyridin-2-one in 5.0 mL DCM is added 186 μL (1.34 mmol) triethylamine and subsequently 69 μL (0.89 mmol) methanesulfonyl chloride at RT. The reaction mixture is stirred 1 h at RT and 74 μL (0.89 mmol) pyrrolidine is added. The mixture is stirred overnight at RT and is directly transferred to a reverse HPLC for purification (Zorbax stable bond, C18; water (0.1% formic acid)/acetonitrile (0.1% formic acid) 95:5 to 10:90).
