Phosphorus pentachloride → heptane-1-sulfonyl chloride
Reaction equation
P(Cl)(Cl)(Cl)(Cl)[Cl:2].[CH2:7]([S:14]([OH:17])(=O)=[O:15])[CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH3:13].[Na]>>[CH2:7]([S:14]([Cl:2])(=[O:17])=[O:15])[CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH3:13]Participants
4
Procedure
To phosphorous pentachloride (3.3 g, 16 mmol) was added solid heptanesulfonic acid, sodium salt monohydrate (1.75 g, 8 mmol) and the mixture was left to stir overnight under nitrogen. Phosphorous oxychloride was removed by distillation at 150° C. for 3 h. The residue was distilled under reduced pressure (ca. 5 mm Hg) at 135° C. to give ca. 1 g of material which was allowed to cool to room temperature. The precipitated free acid was removed by filtration to afford the title compound as an oil (500 mg, 31%) which was used without further purification.