| 摘要 |
1399061 Purification of lactams BAYER AG 14 Sept 1973 [15 Sept 1972] 43196/73 Heading C2C Lactam distillation residues containing boric acid, e.g. from the cyclohexanone oxime rearrangement using boric acid as catalyst, are treated with a polyhydric alcohol and subjected to heating and distillation. The addition of the polyhydric alcohol prevents boric acid and its addition products from depositing in solid form on heating surfaces, and inhibits polymerization of lactam, thereby resulting in increased lactam yields. Exemplified polyhydric alcohols are propane-1,2-diol, glycerol, trimethylolpropane, hexane-1,3,5-triol, pentaerythritol and mannitol. |
