Dimethyl Sulfoxide → 1,3,6,8-tetrachlorodibenzo-p-dioxin

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Reaction Steps

This is a prophetic example. 2.5 gms. of the sodium salt of 2,4,6-trichlorophenol and 5 to 7 mls. of dimethylsulfoxide are stirred at 200-200° C. for 16-24 hours. The reaction mixture is adsorbed on 10 gms. of silica gel, the solvent is allowed to evaporate and the absorbed reaction mixture is placed on top of a silica gel column (60 gms. silica gel, 4×2 mm). The column is eluted with 500 mls. of petroleum spirit. The solvent is removed in vacuo and the residue is recrystallized from 4 mls. of anisole/methanol (1:9) to give a 1-10% yield of 1,3,6,8-tetrachlorodibenzo-p-dioxin. The minor product 1,3,7,9-tetrachlorodibenzo-p-dioxin (2,4,6,8-tetrachlorodibenzo-p-dioxin) can be recovered from the mother liquors and further purified by high pressure liquid chromatography or by recrystallization from anisole/methanol.

Provenance & Evidence