A solution of hydroxylamine hydrochloride (17.0 mg, 0.24 mmol) in methanol (0.5 mL) and 2,6-lutidine (0.5 mL) was treated with 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-N-(5-methyl-pyrazin-2-yl)-3-(4-oxo-cyclohexyl)-propionamide (prepared as in Example 62, 34 mg, 0.066 mmol). The reaction mixture was stirred at 25° C. for 30 min and was then concentrated in vacuo to remove methanol. The resulting residue was suspended in ethyl acetate (10 mL), washed with water 1×5 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 12M, Silica, 65/35 hexanes/ethyl acetate to ethyl acetate) afforded 2(R)-(3-chloro-4-methanesulfonyl-phenyl)-3-(4-hydroxyimino-cyclohexyl)-N-(5-methyl-pyrazin-2-yl)-propionamide (75 mg, 100%) was a white foam: [α]23589=−30.0° (c=0.32 chloroform); EI-HRMS m/e calcd for C21H25ClN4O4S (M+H)+ 465.1358. found 465.1365.
