| 摘要 |
The present invention contemplates a process for the removal of impurities comprising amides, but which may include other impurities such as amines, from a solution of the nitrites and impurities. A reaction mixture is first formed and to that reaction mixture, 0.5 to 3wt% of approximately 60% H2SO4 is stirred in at room temperature and atmospheric pressure for a time effective for the removal of the amide impurities. Typically, after about 30 minutes, the amide impurity is removed into the lower, dark acid layer, probably as a salt. The remaining nitrile, after decantation or filtration, is still colored but is substantially free of amide. In a to second step, at room temperature or at a temperature of up to ~80°C, color can be removed from the nitrile by stirring the acid-washed nitrile with 0.5-5 wt% of clay (bentonite), charcoal, zeolitic type materials, mixtures thereof and the like.
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