Process for producing pentenenitriles

• US 9,932,298 B2
• Filed: 12/05/2013
• Issued: 04/03/2018
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: INV Nylon Chemicals Americas LLC
• Original Assignee: Invista North America Sarl (Invista)
• Inventors: Vos, Thomas E.
• Primary Examiner(s): Kosack, Joseph R
• Application Number:
  US14/649,593
• Publication Number:
  US 20150314279A1
• Time in Patent Office: 1,580 Days
• CPC Class Codes: B01J 2231/322 Hydrocyanation
• CPC Class Codes: B01J 2531/847 Nickel
• CPC Class Codes: B01J 2531/90 Catalytic systems characterized by the solvent or solvent system used
• CPC Class Codes: B01J 31/185 Phosphites ((RO)3P) , their isomeric phosphonates (R(RO)2P=O) and RO-substitution derivatives thereof
• CPC Class Codes: B01J 37/00 Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
• CPC Class Codes: C07C 253/10 to compounds containing carbon-to-carbon double bonds
• CPC Class Codes: C07C 253/30 by reactions not involving the formation of cyano groups
• CPC Class Codes: C07C 253/34 Separation; Purification
• CPC Class Codes: C07C 255/04 containing two cyano groups bound to the carbon skeleton

Abstract

The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.

Claims

1. A process for hydrocyanation of butadiene to adiponitrile, the process comprising:

hydrocyanating butadiene to form adiponitrile, the hydrocyanating comprising contacting 2-methyl-3-butenenitrile and a hydrocyanation catalyst system in a solvent system consisting essentially of cis-2-pentenenitrile, trans-2-pentenenitrile, or a mixture thereof, in the absence of a Lewis acid promoter, wherein an unwanted byproduct of the hydrocyanating of the 2-methyl-3-butenenitrile is converted in situ to a process intermediate pentenenitrile that undergoes further hydrocyanation to provide the adiponitrile, the hydrocyanation catalyst system comprising a soluble complex of nickel and a bidentate ligand of formula (III),

2. The process of claim 1, wherein the solvent system consists essentially of cis-2-pentenenitrile.

3. The process of claim 1, wherein the bidentate ligand is present in a ratio of 1:

4 by weight relative to the solvent system.

4. The process of claim 1 wherein the bidentate ligand is of formula (XII)

5. The process of claim 4 wherein R¹², R¹³, R²², and R²³ are each independently phenyl substituted at a respective single ortho-position with a (C1-C10)alkyl or (C1-C10)alkoxy, wherein respective meta- and para-positions of the R¹², R¹³, R²², and R²³ phenyls can each independently be unsubstituted or be independently substituted with (C1-C10)alkyl, (C3-C10)cycloalkyl, (C1-C10)alkoxy, (C3-C10)cycloalkoxy, (C3-C10)cycloalkyl(C1-C10)alkyl, (C3-C10)cycloalkoxy(C1-C10)alkyl, (C3-C10)cycloalkyl(C1-C10)alkoxy, or (C3-C10)cyclo alkoxy(C1-C10)alkoxy;

R^Y6 and R^Y10 are independently (C1-C10)alkyl or (C1-C10)alkoxy, and R^Y3, R^Y4, R^Y5, R^Y7, R^Y8, and R^Y9, are independently H, (C1-C10)alkyl, or (C1-C10)alkoxy, provided that at least one of R^Y3, R^Y4, or R^Y5, and at least one of R^Y7, R^Y8, or R^Y9, is (C1-C10)alkyl or (C1-C10)alkoxy.

6. The process of claim 1, wherein the bidentate ligand is of formula (V):

7. The process of claim 1, wherein the catalyst system is free of ZnCl₂.

8. The process of claim 1, wherein the solvent system consists essentially of cis-2-pentenenitrile.

9. The process of claim 1, wherein the bidentate ligand is present in a ratio of 1:

4 by weight relative to the solvent system.

10. The process of claim 1, wherein the contacting is performed in the presence of hydrogen cyanide.

11. The process of claim 1, wherein the contacting is performed at a temperature of 80°

C. to 140°

C.

12. The process of claim 1, wherein the contacting is performed at a temperature of 100°

C. to 130°

C.

13. The process of claim 1, further comprising preparing the hydrocyanation catalyst system, comprising:

contacting nickel metal and the bidentate ligand of formula (III) in an organic solvent system consisting essentially of cis-2-pentenenitrile, trans-2-pentenenitrile, or a mixture thereof, under conditions suitable to bring about reaction of the bidentate ligand and the nickel metal to provide an effective concentration of the nickel-ligand complex dissolved in the organic solvent system.

14. The process of claim 13, wherein the conditions to bring about reaction of the bidentate ligand and the nickel metal comprise a temperature of 25-75°

C.

15. The process of claim 14, wherein the conditions to bring about reaction of the bidentate ligand and the nickel metal comprise a temperature of 65°

C.