To a solution of (S)-tert-butyl 3-((3-amino-2-cyanophenoxy)methyl)piperidine-1-carboxylate (Example 2c, 11.0 g, 33.2 mmol) in DMA (100 mL) was added pyridine (13.4 mL, 166 mmol) and sulfamoyl chloride (7.64 g, 66.4 mmol) in small portions. The mixture was stirred at room temperature under nitrogen for 1 hour until the reaction was complete according to LCMS. Saturated NaHCO3 was added until the mixture was neutral and the solution was extracted with EtOAc (3×). The combined organics were dried over Na2SO4 and concentrated. The residue was diluted with EtOH (100 mL) and NaOH (66.4 mL, 132.8 mmol, 2M solution) was added and the solution was heated to 80° C. for 3 hours. The reaction mixture was then allowed to cool to room temperature. The solution was further cool to 0° C. and neutralized with 2N HCl. Water was added and the desired product crashed out. The product was then filtered off and dried to yield the title compound (7.0 g, 51.4%). (M+H)−Boc=311.
