Tetrahydrofuran → 3-(Cyclobutylamino)propane-1-sulfonic acid

A mixture of cyclobutylamine (1.11 g, 15.6 mmol) and 1,3-propane sultone (2 g, 17 mmol) in acetonitrile (18 mL) was heated at reflux. The mixture turned to a lump within 15 minutes. THF (10 mL) was added. The reflux was maintained for 1 hour. The mixture was cooled to room temperature. The solid was collected by filtration, rinsed with acetonitrile (2×4 mL), air-dried for 60 minutes (2.41 g). The solid was suspended in methanol (20 mL) and the suspension was heated at reflux until all the solid material was dissolved. The mixture was then cooled to room temperature. The solid thus formed was collected by suction filtration, rinsed with methanol (2×4 mL), air-dried for 20 minutes, and further dried in a vacuum oven at 40° C. for 18 hours. Compound EC was obtained as a white solid (1.81 g, 60% yield). 1H NMR (500 MHz, D2O) δ 1.70-1.77 (m, 2H), 1.94-2.03 (m, 4H), 2.18 (br s, 2H), 2.85 (t, J=6.8 Hz, 1H), 2.95 (t, J=7.3 Hz, 1H), 3.63-3.66 (m, 1H). 13C NMR (125 MHz, D2O) δ 14.5, 21.5, 26.1, 43.6, 48.0, 51.8. ES-MS 194 (M+1).

1. temperaturewas heated
2. temperatureat reflux
3. temperatureThe reflux was maintained for 1 hour
4. filtrationThe solid was collected by filtration
5. washrinsed with acetonitrile (2×4 mL)
6. customair-dried for 60 minutes (2.41 g)
7. temperaturethe suspension was heated
8. temperatureat reflux until all the solid material
9. dissolutionwas dissolved
10. temperatureThe mixture was then cooled to room temperature
11. customThe solid thus formed
12. filtrationwas collected by suction filtration
13. washrinsed with methanol (2×4 mL)
14. customair-dried for 20 minutes
15. customfurther dried in a vacuum oven at 40° C. for 18 hours

ORD record

ord-891f548053204af48cd80d62c0ee5c00

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08642801B2