Propane sultone → 3-{[(1r)-1-(Hydroxymethyl)-3-methylbutyl]amino}-1-propanesulfonic acid

To a solution of D-(−)-leucinol (2.0 g, 17.1 mmol) in THF (30 mL) was slowly added 1,3-propanesultone (1.94 g, 16.3 mmol). The solution was 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 50% water/EtOH (240 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 (50 mL), filtered and dried in the vacuum oven (50° C.), affording the title compound (2.55 g, (65%). 1H NMR (D2O, 500 MHz) δ ppm 3.74 (d, 1H, J=12.7 Hz), 3.56 (d, 1H, J=12.7 Hz), 3.20 (m, 1H), 3.10 (t, 2H, J=7.3 Hz), 2.87 (t, 2H, J=7.3 Hz), 2.00 (m, 2H), 1.49 (m, 2H), 1.31 (m, 1H), 0.80 (d, 3H, J=6.3 Hz), 0.76 (d, 3H, J=6.3 Hz). 13C (D2O, 125 MHz) δ ppm 58.74, 58.01, 48.19, 43.56, 35.98, 24.34, 22.54, 21.63, 20.90. [α]D=−16.3° (c=0.0019 in water), ES-MS 238 (M−1).

1. temperatureat reflux for 2 hours
2. filtrationThe solid was collected by filtration
3. washwashed with acetone (2×20 mL)
4. dissolutionThe solid was dissolved in 50% water/EtOH (240 mL)
5. additionDowex Marathon C ion exchange resin (strongly acidic) was added to the solution
6. stirringThe suspension was stirred for 15 minutes before the resin
7. customwas removed by filtration
8. customThe filtrate was evaporated under reduced pressure
9. filtrationfiltered
10. customdried in the vacuum oven (50° C.)

ORD record

ord-575f33b13b874ae0ae5c53876cead489

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08642801B2