Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (2R)-4-(5-fluoro-2-oxo-4-phenylpyridin-1(2H)-yl)-N-hydroxy-2-methyl-2-(methylsulfonyl)butanamide

Pyridinium p-toluenesulfonate (22 mg, 0.088 mmol) was added to a solution of (2R)-4-(5-fluoro-2-oxo-4-phenylpyridin-1(2H)-yl)-2-methyl-2-(methylsulfonyl)-N-(tetrahydro-2H-pyran-2-yloxy)butanamide (197 mg, 0.422 mmol). The solution was heated to reflux in ethanol (10 ml) and stirred at this temperature until complete. The solution was cooled to RT, and the volatiles were removed in vacuo. The solid was triturated in ethanol (5 mL), collected via filtration, then washed with ethanol (3×5 mL), hexanes (10 mL), and ether (3×10 mL). The solid was dried under vacuum to afford a white solid (85.1 g, 76.4%). LC-MS m/z 383.1 (M+1). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.58 (s, 3H) 2.11-2.23 (m, 0H) 2.41-2.55 (m, 1H) 3.12 (s, 3H) 3.73-3.84 (m, 1H) 3.99-4.11 (m, 1H) 6.53 (d, J=7.61 Hz, 1H) 7.41-7.73 (m, 5H) 8.04 (d, J=6.44 Hz, 1H) 9.24 (s, 1H) 11.10 (s, 1H).