Triethylamine → tert-Butyl N-allyl-N-[2-(methoxy(methyl)amino)-2-oxo-ethyl]carbamate

Participants

Reaction Conditions

Reaction Steps

2-(Allyl(tert-butoxycarbonyl)amino)acetic acid (49.6 g, 156 mmol), tetrahydrofuran (600 mL), and triethylamine (36.3 g, 359 mmol) is added to an Erlenmeyer flask and the mixture is cooled to 0° C. Pivaloyl chloride (31 g, 253 mmol) is added drop wise and the reaction is stirred at room temperature for 3 hours and then cooled to 0° C. N,O-dimethylhydroxylamine hydrochloride (28 g, 283 mmol), triethylamine (33 mL, 237 mmol) and tetrahydrofuran (400 mL) are then added. The ice bath is removed and the reaction is stirred at room temperature for 3 hours. The mixture is concentrated under reduced pressure. The resulting residue is dissolved in water (300 mL) and extracted with ethyl acetate (2×300 mL). The organic phases are combined, dried over magnesium sulfate, filtered, and concentrated under reduced pressure to give a residue. The residue is purified by silica gel flash chromatography, eluting with hexane/acetone (1:0) to hexane/acetone (1:1) to give the title compound (32 g, 54%). 1H NMR (CDCl3) mixture of two rotamers (60:40) δ 1.42, 1.44 (s, 9H), 3.16, 3.17 (s, 3H), 3.66, 3.69 (s, 3H), 3.88-3.98 (m, 2H), 4.01, 4.11 (s, 2H), 5.10-5.18 (m, 2H), 5.73-5.85 (m, 1H).

Provenance & Evidence