4-Methylmorpholine → (S)-2-(Boc-amino)-3-cyclohexyl-N-methoxy-N-methylpropanamide

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Reaction Steps

To a solution of dimethylhydroxylamine hydrochloride (3.98 g, 40.6 mmol) in DCM (50 mL) at 0° C. was added triethylamine (5.43 mL, 41.9 mmol). In a separate flask (S)-2-((tert-butoxycarbonyl)amino)-3-cyclohexylpropanoic acid (10.0 g, 36.9 mmol) in DCM (50 mL) and THF (50 mL) was cooled to 0° C. and isobutylchloroformate (4.83 mL, 36.9 mmol) was added followed by N-methylmorpholine (4.06 mL, 36.9 mmol). After 1 h it was added to the dimethylhydroxylamine mixture. The combined mixture was allowed to warm to ambient temperature over 16 h at which time it was quenched with water, washed with sodium bicarbonate (sat.), extracted with EtOAc (2×), washed with brine, dried with sodium sulfate, filtered, and concentrated. (S)-tert-Butyl (3-cyclohexyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate (12.2 g) was provided as a colorless oil that was carried forward without further purification. MS (EI) for C16H30N2O4, found 215.3 [M-Boc]+.

Provenance & Evidence