Taurine → 2-Phthalimidoethanesulfonyl chloride

A suspension of taurine (8.0 g, 63.9 mmol) and potassium acetate (6.7 g, 68.3 mmol) in acetic acid was refluxed for 15 min. Phthalic anhydride (10.1 g, 68.4 mmol) was added and the solution was refluxed for 3 h. The reaction was cooled to room temperature and the solid was filtered off, washed with cold acetic acid and dried under vacuum at 100° C. to give a white solid. The solid (14.3 g, 54.7 mmol) was suspended in toluene (50 ml) and phosphorus pentachloride (8.12 g, 39.0 mmol) was added under nitrogen. The reaction mixture was heated under reflux for 1 h. Further phosphorus pentachloride (8.12 g, 39.0 mmol) was added and the reaction mixture was refluxed for 2.5 h. The brownish solution was decanted from the small amount of solid formed and then concentrated in vacuo, the residue was poured onto ice:water (50:50, 100 ml) and filtered. The solid was dried for 16 h in vacuo at 45° C. to give a pale brown solid (6.4 g, 34%).

1. temperaturewas refluxed for 15 min
2. temperaturethe solution was refluxed for 3 h
3. filtrationthe solid was filtered off
4. washwashed with cold acetic acid
5. customdried under vacuum at 100° C.
6. customto give a white solid
7. temperatureThe reaction mixture was heated
8. temperatureunder reflux for 1 h
9. temperaturethe reaction mixture was refluxed for 2.5 h
10. customThe brownish solution was decanted from the small amount of solid
11. customformed
12. concentrationconcentrated in vacuo
13. additionthe residue was poured onto ice:water (50:50, 100 ml)
14. filtrationfiltered
15. customThe solid was dried for 16 h in vacuo at 45° C.

ORD record

ord-6b6cfcdbc5d047528697902eb0fb7c30

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07049444B2