To a cold solution of 2,3-dioxo-2,3-dihydro-1-H-indole-5-sulfonylchloride (3.80 g, 15.5 mmol ) in a 1:1 mixture of THF:CHCl3 (194 mL) was added drop-wise via syringe pump a solution of (2S)-2-(phenoxymethyl)pyrrolidine (2.85 g, 16.1 mmol, 1.03 eq) (J. Med. Chem, 44, 2014, 2001) and N,N-diisopropylethylamine (5.61 mL, 32.2 mmol, 2 eq) in CHCl3 (30 mL) over a period of 50 minutes under a dry N2 atmosphere with cooling in an ice bath. After stirring at room temperature for 64 hr the reaction mixture was concentrated and the crude product was flash chromatographed twice using Biotage KP silica gel, and gradient of 98/2 CH2Cl2/CH3OH as eluent on the first column and 90/10 CH2Cl2/CH3OH as eluent on the second column to give the title compound as a dark green solid (5.29 g, 88% yield). NMR (400 MHz, DMSO-d6): consistent. MS: (ES−) m/z 385 [M−H]. MS: (ES+) m/z 387 [M+H].
