Taurine → 2-Phthalimidoethanesulfonyl chloride

Participants

Reaction Steps

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%).

Provenance & Evidence