1,1'-Carbonyldiimidazole → (S)-N-methyl-N-methoxy-2-(tert-butoxycarbonylamino)-4-methylpentanamide

Participants

Reaction Steps

To a solution of N-(tert-butoxycarbonyl)-L-leucine (3.00 g, 13.0 mmol) in THF (25.0 mL) was added 1,1′-carbonyldiimidazole (2.52 g, 15.6 mmol) portionwise over about 10 min. After stirring 1 h at RT, a solution of N,O-dimethylhydroxylamine hydrochloride (1.39 g, 14.3 mmol) and DIPEA (2.49 mL, 14.3 mmol) in DMF (6.0 mL) was added. The reaction mixture was stirred for 2.5 h at RT, followed by concentration in vacuo. The residue was diluted with EtOAc (50 mL) and washed with 1 M aq. HCl (2×20 mL), saturated aq. NaHCO3 (2×20 mL), and brine (20 mL). The organic layer was dried over Na2SO4, filtered, and concentrated in vacuo to afford the title compound (2.34 g, 66%) as a clear, colorless oil. LC-MS m/z 275 (M+H)+, 1.17 min (ret time).

Provenance & Evidence