Benzyl (3-{2-[methoxy(methyl)amino]-2-oxoethyl}phenyl)carbamate → Benzyl [3-(2-oxobut-3-en-1-yl)phenyl]carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of 15 g (45.7 mmol) of benzyl (3-{2-[methoxy(methyl)amino]-2-oxoethyl}phenyl)carbamate (from Step C) in 1000 mL anhydrous THF under nitrogen atmosphere cooled to 0° C. via ice/water bath was added dropwise via cannula a 1.0 M solution of vinyl magnesium bromide (100 mL in THF, 100 mmol) and the resulting solution stirred for 1 h at 0° C. The reaction was quenched by a slow addition of 500 mL 1 M HCl keeping the temperature below 5° C. and stirred for 30 min. The mixture was then extracted with ethyl acetate and the combined organics washed with water followed by brine. The organics were then dried over sodium sulfate, filtered, and concentrate under vacuum. The residue was purified by Biotage 75M flash eluting with 30% ethyl acetate in hexane to afford the title compound (11 g, 78%) as a light yellow solid. LC-MS: m/z (ES) 310 (MH)+, 332 (MNa)+. 1HNMR (500 MHz, CDCl3) δ: 7.44-7.36 (m, 7H), 7.18 (d, J=8.4 Hz, 2H), 6.70 (br s, 1H), 6.44 (dd, J=10.5, 17.6 Hz, 1H), 6.32 (dd, J=1.1, 17.6 Hz, 1H), 5.85 (dd, J=1.1, 10.5 Hz, 1H), 5.22 (s, 2H), 3.86 (s, 2H).

Provenance & Evidence