Method for separating an azepine derivative out of a mixture containing an amine an azepine derivative

• US 7,147,757 B2
• Filed: 03/06/2001
• Issued: 12/12/2006
• Est. Priority Date: 03/08/2000
• Status: Expired due to Fees

• Current Assignee: BASF AG (BASF SE)
• Original Assignee: BASF AG (BASF SE)
• Inventors: Luyken, Hermann, Ohlbach, Frank
• Primary Examiner(s): Manoharan, Virginia
• Application Number:
  US10/204,966
• Publication Number:
  US 20030023083A1
• Time in Patent Office: 2,107 Days
• Field of Search: 203/2, 203/49, 203/73, 203/78, 203/80, 203/28, 203/77, 203/DIG.25, 540/605, 540/612, 540/540, 564/439, 564/437, 564/497, 558/452
• US Class Current: 203/2
• CPC Class Codes: C07C 209/86 Separation
• CPC Class Codes: C07C 253/34 Separation; Purification
• CPC Class Codes: C07D 223/04 with only hydrogen atoms, halogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
• CPC Class Codes: C07D 223/12 Nitrogen atoms not forming part of a nitro radical
• CPC Class Codes: Y10S 203/90 Particular type of heating

Abstract

The invention relates to a method for separating by distillation a portion or the entirety of an azeptine derivative (III), which is selected from the group consisting of aminohexylidene imine, tetrahydroazepine, hexylhexahydroazepine and of aminohexylhexahydroazepine, out of a mixture (II) containing an azepine derivative (III) and an amine (I). The inventive method is characterized in that the distillation is carried out with a maximum bottom temperature of 150° C.

Claims

1. A process for distillative removal of part or all of an azepine derivative (III) selected from the group consisting of tetrahydroazepine, 2-aminoazepan, N-(2-azepano)-1,6-diaminohexane and N-(2-azepano)-6-aminocapronitrile from a mixture (II) comprising an azepine derivative (III) and an amine (I), which comprises conducting the distillation at a pot temperature of not more than 120°

C., and wherein the distillation provides said azepine derivative (III) predominantly as bottom product (VI) and said bottom product (VI) is subjected to a hydrogenation.

2. A process as claimed in claim 1, wherein said bottom product (VI) is used in a hydrogenation to prepare an amine (I).

3. The process of claim 1, wherein the amine (I) is 6-aminocapronitrile or hexamethylenediamine.

4. A process for distillative removal of part or all of an azepine derivative (III) selected from the group consisting of tetrahydroazepine, 2-aminoazepan, N-(2-azepano)-1,6-diaminohexane and N-(2-azepano)-6-aminocapronitrile from a mixture (II) comprising an azepine derivative (III) and an amine (I), which comprises conducting the distillation at a pot temperature of not more than 120°

C., and wherein the distillation is carried out in two stages, the pressure in the first stage, measured in the pot, is at least 1.5 times the pressure in the second stage, measured in the pot, not less than 20% by weight of the amount fed into the first stage per unit time is removed from the pot of the first stage and fed to the second stage; and

the overhead product of the second stage is recycled into the first stage.

5. The process of claim 4, wherein the amine (I) is 6-aminocapronitrile or hexamethylenediamine.

6. A process of distillative removal, of part or all of an azepine derivative (III) selected from the group consisting of tetrahydroazepine, 2-aminoazepan, N-(2-azepano)-1,6-diaminohexane and N-(2-azepano)-6-aminocapronitrile from a mixture (II) comprising an azepine derivative (III) and an amine (I), which comprises conducting the distillation at a pot temperature of not more than 120°

C.,and wherein the distillation is carried out in the presence of carbon dioxide.

7. The process of claim 6, wherein the amine (I) is 6-aminocapronitrile or hexamethylenediamine.