Process for the preparation of sterically hindered nitroxyl ethers

• US 8,471,031 B2
• Filed: 06/25/2007
• Issued: 06/25/2013
• Est. Priority Date: 07/05/2006
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Schning, Kai-Uwe, Fischer, Walter, Basbas, Abdel-Ilah, Dichtl, Alexander
• Primary Examiner(s): Balasubramanian, Venkataraman
• Application Number:
  US12/308,519
• Publication Number:
  US 20100249401A1
• Time in Patent Office: 2,192 Days
• Field of Search: 546/184, 546/188, 546/189, 544/19, 544/209, 544/198
• US Class Current: 546/184
• CPC Class Codes: C07B 43/00 Formation or introduction of functional groups containing nitrogen
• CPC Class Codes: C07D 211/94 Oxygen atom, e.g. piperidine N-oxide

Abstract

The present invention relates to a novel process for the preparation of a sterically hindered nitroxyl ether from the corresponding sterically hindered nitroxyl radical by reacting it with a carbonyl compound and a hydroperoxide. The compounds prepared by this process are effective stabilizers for polymers against harmful effects of light, oxygen and/or heat, as flame-retardants for polymers and as polymerization regulators.

Claims

1. A process for the preparation of a sterically hindered nitroxyl ether which comprises reacting a corresponding sterically hindered nitroxyl radical with a carbonyl compound in the presence of a hydroperoxide and a metal catalyst,

with the proviso that, if the sterically hindered nitroxyl radical is 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), the ketone is not acetone,

where the carbonyl compound is an aldehyde, diketone, dialdehvde, oligoketone or oligoaldehyde and

wherein the sterically hindered nitroxyl radical is selected from the group consisting of formulae (A)-(O)

2. A process according to claim 1 wherein the carbonyl compound is a ketone, aldehyde, diketone or dialdehyde of formula (Ia) or (Ib)

3. A process according to claim 2 wherein the carbonyl compound is a ketone or aldehyde of formula (Ia)

4. A process according to claim 3 wherein R₁₀₁ and R₁₀₂ are hydrogen or straight or branched chain C₁-C₁₂alkyl, which alkyl may be unsubstituted or substituted by 1 OH group.

5. A process according to claim 1 wherein the hydroperoxide is of formula (II)

6. A process according to claim 5 wherein the hydroperoxide is tert-butyl hydroperoxide, cumyl hydroperoxide or H₂O₂.

7. A process according to claim 1 wherein the metal catalyst is a salt or a complex of Ag, Mn, Fe, Cu, Zr, Na, Mg, Ca, Al, Pd, In, Bi or Ce in any oxidation state.

8. A process according to claim 7 wherein the metal catalyst is a salt or a complex of Fe, Cu, Mn, Na, Mg, Pd, In, Zr or Bi in any oxidation state.

9. A process according to claim 7 wherein the metal catalyst is a Fe²⁺ or Fe³⁺, a Cu⁺ or Cu²⁺, a Na⁺ or a Ca²⁺ salt.

10. A process according to claim 1 wherein G₁ and G₃ are ethyl and G₂, G₄ and G₅ are methyl or G₁ and G₂ are methyl, G₃ and G₄ are ethyl and G₅ is hydrogen or G₁, G₂, G₃ and G₄ are methyl and G₅ is hydrogen.

11. A process according to claim 1 wherein G₁, G₂, G₃ and G₄ are methyl and G₅ is hydrogen.

12. A process according to claim 1 wherein the sterically hindered nitroxyl radical is of formula (A), (B), (B′

), (C), (C′

), (G), (N) or (O).

13. A process according to claim 1 wherein the resulting sterically hindered nitroxyl ether contains a structural element of formula (XI)