METHOD OF PURIFYING HEXAMETHYLENEDIAMINE Russian patent published in 2013 - IPC C07C209/84 C07C211/12 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of purifying hexamethylenediamine (HMD) from tetrahydroazepine (THA) by distillation, in a distillation column, of a mixture containing hexamethylenediamine and tetrahydroazepine, with dwell time of the mixture in a portion of internal elements of the column, lying higher than the point of feeding the hexamethylenediamine to be purified, of 1-20 minutes. The dwell time is preferably 1-15 minutes. The number of theoretical plates of the distillation column is preferably 10-50; temperature in the bottom part of the distillation column is in the range from 120 to 170°C. Distillation is preferably carried out in a structured packing column. The purified hexamethylenediamine contains less than 8 moles THA per million moles HMD and can contain less than 4 moles THA per million moles HMD. For ordinary distillation, the hexamethylenediamine collected from the top part of the column contains 16.4 moles THA per million moles HMD.

EFFECT: method considerably reduces content of THA.

4 ex, 7 cl