Propane sultone → 3-{[(1S)-1-benzyl-2-(benzyloxy)-2-oxoethyl]amino}propane-1-sulfonic acid

Participants

Reaction Steps

To a solution of L-Phenylalanine benzylester (1.8 g, 6.8 mmol) in 1,4-dioxane (10 mL) was added 1,3-propanesultone (708 mg, 6.5 mmol). The solution was stirred at reflux. After 1 hour, 20 mL of 1,4-dioxane was added to allow for good stiffing. The reaction was stirred at reflux for an additional 1 hour. It was cooled to room temperature. The solid was collected by filtration, washed with acetone (2×25 mL). The product was suspended 80% Acetone/EtOH. The suspension was stirred at reflux for 30 seconds. The solid was filtered and dried in the vacuum oven (50° C.) affording the title compound (1.14 g, 46%). 1H NMR (DMSO, 500 MHz) δ ppm 7.27 (m, 6H), 7.12 (m, 4H), 5.05 (dd, 2H, J=12.3 Hz), 4.49 (m, 1H). 3.29 (m, 1H), 3.00 (m, 1H), 2.98 (m, 1H), 2.61 (t, 2H, J=6.5 Hz), 1.97 (m, 2H). 13C (DMSO, 125 MHz) δ ppm 168.88, 135.21, 134.90, 130.00, 129.31, 129.07, 128.01, 67.98, 60.50, 49.77, 46.72, 35.87, 22.43. [α]D=+4.8° (c=0.00073 in water), ES-MS 378 (M+1).

Provenance & Evidence