Compositions – Preservative agents – Anti-oxidants or chemical change inhibitants
Patent
1997-09-22
1999-07-13
Rotman, Alan L.
Compositions
Preservative agents
Anti-oxidants or chemical change inhibitants
546186, 546244, C09K 1520, C07D21158
Patent
active
059222441
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
4-Acylaminopiperidine N-oxides
The present invention relates to novel 4-acylaminopiperidine N-oxides of the general formula Ia the general formula IIa ##STR2## where
R.sup.1 -R.sup.4 are each C.sub.1 -C.sub.4 -alkyl and R.sup.1 and R.sup.2, on the one hand, and R.sup.3 and R.sup.4, on the other hand, may furthermore be bonded to form a 5-membered or 6-membered ring,
R.sup.5 is H or C.sub.1 -C.sub.4 -alkyl and
R.sup.6 is H or C.sub.1 -C.sub.18 -alkyl.
The present invention also relates to a process for the preparation of the compounds Ia, the use of the compounds for stabilizing organic materials against the harmful effect of free radicals, in particular of styrene during distillation, the joint use of the compounds Ia or Ib with aromatic nitro or nitroso compounds or substituted phenols, and liquid or solid organic materials which contain the compounds Ia.
Description of the Background
The stabilization of organic materials against damage by free radicals, as formed under the influence of light or heat, is generally known. Compounds from various classes of substances, including the N-oxides of various derivatives of 2,2,6,6-tetramethylated piperidines, have been proposed to date as stabilizers for this purpose.
One compound of this type, which is derived from 4-amino-2,2,6,6-tetramethylpiperidine N-oxide, is the bisamide of adipic acid ##STR3## which is described in SU-A 1 139 722. Similar known compounds contain the ester or carbamate group (EP-A 0 581 737 and SU-A 1 027 150, respectively) instead of the carboxamido group.
Furthermore, EP-A 0 581 737 discloses that the stabilizing effect of N-oxides is increased if they are used together with aromatic nitro compounds.
In addition, EP-B 0 316 582 discloses non-free radical piperidine derivatives having the structural unit ##STR4## which are suitable as stabilizers for organic material.
SUMMARY OF THE INVENTION
Since the N-oxides known to date have an unsatisfactory action, it is an object of the present invention to provide novel N-oxides having improved performance characteristics.
We have found that this object is achieved by the 4-acylaminopiperidine N-oxides defined at the outset.
We have also found a process for the preparation of the compounds Ia and Ib, the use of these compounds for stabilizing organic materials, their joint use with other stabilizers, and liquid or solid organic materials which contain the compounds Ia or Ib.
DETAILED DESCRIPTION OF THE INVENTION
The structural element of the compounds Ia which is essential for the stabilizing properties is the moiety B.sup.1 of the general formula IIa.
In this formula, R.sup.1 to R.sup.4 may be alkyl, such as methyl, ethyl, propyl or butyl, methyl being particularly preferred. Alicyclic radicals in which R.sup.1 and R.sup.2 or R.sup.3 and R.sup.4 together form a tetramethylene or a pentamethylene group are also suitable.
R.sup.5 may likewise be alkyl, such as methyl, ethyl, propyl or butyl, but is preferably hydrogen.
Suitable radicals R.sup.6 are lower alkyl, such as methyl, ethyl, propyl, butyl or longer-chain radicals of up to 18 carbon atoms. However, R.sup.6 is preferably hydrogen, so that in this case the amino group carries a formyl radical.
The moiety A.sup.1 serves in particular for adapting the chemical and physical properties of the compounds to the various intended uses. By varying the moiety A.sup.1, for example, the solubility in various organic materials, the volatility and the compatibility with other assistants can be influenced.
In addition to being hydrogen, A.sup.1 may be, for example, n-butyl, isobutyl, n-pentyl, isopentyl, hexyl, octyl, decyl, dodecyl, octadecyl, pivalyl, 3,3-dimethylbut-2-yl, neopentyl, 4-methylpent-2-yl or 2-ethylhexyl, cyclopentyl, cyclohexyl, methylcyclohexyl, cycloheptyl, cyclooctyl, cyclododecyl or bicycloheptyl, especially cyclopentyl or cyclohexyl, as cyanomethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, carbomethoxyethyl or carboethoxyethyl, or substituted by hydroxyl, such as --(CH.sub.2).sub.3 N(CH.sub.3).su
REFERENCES:
Database Crossfire, Beilstein Informationssyteme GmbH, Frankfurt DE, pp. 1446-1457.
Database Crossfire, Beilstein Informationssyteme GmbH, Frankfurt DE, pp. 207-213.
Database Crossfire, Beilstein Informationssyteme GmbH, Frankfurt DE, p. 2106.
Database Crossfire, Beilstein Informationssyteme GmbH, Frankfurt DE, p. 1100.
Chemical Abstracts, vol. 99, No. 26, Dec. 26, 1983. M.D. Goldfein et al. "Stabilization of Styrene or Methyl Methacrylate", p. 8.
Macromolecules, Bd 23, Nr. 3. Feb. 5, 1990. E.J. Vlietstra et al. Synthesis and Magnetic Properties of a Rigid High Spin Density Polymer with Piperidine-N-Oxyl Pending Groups, p. 946.
Investigative Radiology Bd. 21. Feb. 2, 1986. Richard L. Ehman et al. Diradical Nitroxyl Spin Label contrast Agents for magnetic Resonance Imaging. A Comparison of Relaxation Effectiveness, p. 126.
Journal of the American Chemical Society, Bd. 99. Mar. 2, 1977. Paul Rey et al. Clustering of Nitroxide Spin Labels in Lipid Bilayer Membranes, p. 1638.
Journal of Organic Chemistry, Bd. 56. Oct. 11, 1991. Zhenkun Ma et al. "Organic Oxoammonium Salts. 3.1 A New Convenient Method for the Oxidation of Alcohols to Aldehydes and Ketones", p. 6114.
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. Feb. 20, 1986. G. N. Bondarev et al. Synthesis of 2,2,6,6-Tetramethyl-4-Diaminoalkylpiperidin-1-Oxyls, p. 1701.
Bulletin of Academy of Sciences of the USSR Division of Chemical Science. Aug. 20, 1986. G. N. Bondarev et al. "Synthesis of 2,2,6,6-Tetramethyl-4-Amino-N-(Alkylmaleimido)-Piperidyl-1-Oxides", pp. 363 and 366.
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science. Jan. 20, 1989. "Synthesis of 2,2,6,6-Tetramethyl-4-Amino-N-(Alkylaminodichlortriazine)-1-Oxylpiperidine s" p. 1455.
Aumuller Alexander
Herbst Holger
Koch Andreas
Mitulla Konrad
Tremmel Gregor
Aulakh Charanjit S.
BASF - Aktiengesellschaft
Rotman Alan L.
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