Saccharin → Pseudosaccharin chloride

Participants

Reaction Steps

Following the procedure of Stephen et al., J. Chem. Soc., 1957, 490-92, 1 mol of saccharin (1,2-benzisothiazol-3(2H)-one 1,1-dioxide) is heated with 1.1 mol phosphorus pentachloride at 170° C. for 1.5 hours. Phosphorus oxychloride is removed at 60°/30 mm and the yellow crystalline residue of ψ-saccharin chloride and o-cyanobenzene sulfonyl chloride is treated with ether in which the latter is soluble. The sparingly soluble ψ-saccharin chloride in a yield of 28% is collected and crystallized from ether as white needles, m.p. 132°-137° C.

Provenance & Evidence