Triethylamine → Tert-butyl 3-(methoxy(methyl)amino)-3-oxopropyl(methyl)carbamate

Participants

Reaction Steps

To a stirred solution of 3-[(tert-butoxycarbonyl)(methyl)amino]-propanoic acid (5.0 g, 24.6 mmol), N,O-dimethylhydroxylamine hydrochloride (3.1 g, 32.0 mmol) and HBTU (11.2 g, 29.5 mmol) in DMF (50 mL) at 0° C. was added triethylamine (10.2 mL, 73.8 mmol). The mixture was stirred at room temperature over night and the solvent was removed under reduced pressure. The residue was taken up in ethyl acetate (300 mL), washed with water (100 mL) and 0.6 N NaOH solution (100 mL). The aqueous phases were back extracted with ethyl acetate (100 mL). The combined organic phases were dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography on silica gel (120 g column, 0% ethyl acetate in hexanes to 100% ethyl acetate in hexanes) to give product (6.0 g, 99%). 1H NMR (CDCl3) 3.69 (s, 3H), 3.52 (t, J=6.2 Hz, 2H), 3.18 (s, 3H), 2.88 (s, 3H), 2.66 (brs, 2H), 1.45 (s, 9H); MS EI m/z 269 (M+Na)+.

Provenance & Evidence