摘要 |
In the purification of thionyl chloride by addition of sulphur and distillation in the presence of a catalyst, the improvement which comprises effecting the distillation in the presence of an aluminum compound as the catalyst. Advantageously the aluminum compound is aluminum chloride, the sulphur is added in about 2.5 to 7% by weight based on thionyl chloride, the aluminum chloride is in admixture with sulphur monochloride in about 0.01 to 5% by weight calculated as aluminum and based on thionyl chloride, and prior to distillation the mixture of crude thionyl chloride, sulphur and aluminum chloride is heated to between about 50 DEG and 60 DEG C. for about 10 to 60 minutes. The resulting thionyl chloride is of extremely high purity.
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