Propane sultone → 3-{[(1S)-2-tert-butoxy-1-methyl-2-oxoethyl]amino}-1-propanesulfonic acid

Participants

Reaction Steps

To a solution of L-Alanine tert-butylester (1.53 g, 10.5 mmol) in tetrahydrofuran (20 mL) was added 1,3-propanesultone (1.16 g, 9.6 mmol). The solution stirred at reflux for 2 hours. The reaction was cooled to room temperature. The solid was collected by filtration and washed with acetone (2×20 mL). The solid was dissolved in water (80 mL). Dowex Marathon C ion exchange resin (strongly acidic) was added to the solution. The suspension was stirred for 15 minutes before the resin was removed by filtration. The filtrate was evaporated under reduced pressure. The solid was suspended in acetone (80 mL), filtered and dried in the vacuum oven (50° C.), affording the title compound (1.37 g, 54%). 1H NMR (D2O, 500 MHz) δ ppm 3.88 (m, 1H), 3.09 (m, 2H), 2.86 (t, 2H, J=7.3 Hz), 2.00 (m, 2H), 1.39 (d, 3H, J=7.3 Hz), 1.35 (s, 9H). 13C (D2O, 125 MHz) δ ppm 169.13, 86.12, 56.24, 47.94, 44.71, 27.11, 21.52, 14.17. [α]D=−1.1° (c=0.0027 in water), ES-MS 266 (M−1).

Provenance & Evidence