Patent Application
20050104042
The instant invention pertains to a process for preparing amine ethers, e.g. N-hydrocarbyloxy substituted hindered amine compounds, by the reaction of the corresponding N-oxyl intermediate with a hydrocarbon in presence of an organic hydroperoxide and an iodide catalyst.
4-Hydroxy-1-oxyl-2,2,6,6-tetramethylpiperidine and 4-oxo-1-oxyl-2,2,6,6-tetramethylpiperidine are described as scavengers for some carbon centered radicals (S. Nigam et al., J. Chem. Soc., Trans. Faraday Soc., 1976, (72), 2324 and by K.-D. Asmus et al., Int. J. Radiat. Biol., 1976, (29), 211).
D. H. R. Barton et al., Tetrahedron, 1996, (52), 10301 describe the formation of some N-alkoxy-2,2,6,6-tetramethylpiperidine derivatives in the reaction of hydrocarbons with iron(II) and iron(III) species, hydrogen peroxide and various coadditives in the presence of N-oxyl-2,2,6,6-tetramethylpiperidine (TEMPO).
U.S. Pat. No. 5,374,729 describes a process for the preparation of N-methoxy derivatives of hindered amines from the reaction of the corresponding N-oxyl compound with methyl radicals produced from dimethyl sulfoxide by decomposing aqueous hydrogen peroxide in presence of a metal salt or by thermal decomposition of di-tert.butyl peroxide.
U.S. Pat. No. 4,921,962 describes a process for the formation of N-hydrocarbyloxy derivatives of sterically hindered amines in which a hindered amine or N-oxyl substituted hindered amine is reacted with a hydrocarbon solvent in the presence of a hydroperoxide and a molybdenum catalyst.
It has now been found that N-hydrocarbyloxy substituted sterically hindered amines can most suitably be prepared from the N-oxyl intermediate and a hydrocarbon in presence of an organic hydroperoxide and an iodide catalyst. The process of the invention uses only catalytic quantities of iodide and does not require high temperatures.
Thus, present invention pertains to a process for the preparation of an amine ether of a sterically hindered amine by reacting a corresponding sterically hindered aminoxide with an aliphatic hydrocarbon compound, characterized in that the reaction is carried out in the presence of an organic hydroperoxide and an iodide, which is preferably used in a catalytic amount.
The aliphatic hydrocarbon compound may be any compound selected from alkane, alkene, alkyne, or cyclic or polycyclic analogues thereof, and optionally may be substituted, e.g. by aryl, halogen, alkoxy etc., provided that an aliphatic CH (or CH2, CH3) moiety is contained.
Advantageously, the process of the invention is carried out in the absence of a copper or a copper compound, preferably in the absence of any heavy metal or heavy metal compound. Heavy metal is to be understood as transition metal or any metal of higher molecular weight than calcium. Metal compounds, the presence of which is advantageously to be avoided in the present process, include any form like salts, complexes, solutions and dispersions thereof. The amounts of these compounds to be tolerated within the process of the invention are preferably well below the catalytic level, e.g. below 0.0001 molar equivalent per mole of nitroxyl moiety, more preferably within or below the ppm-level (up to 1000 parts by weight of heavy metal per 1 million parts by weight of total reaction mixture).
Preferred is a process for the preparation of an amine ether of the formula A
wherein
E′ is C1-C36 alkyl; C3-C18 alkenyl; C2-C18 alkinyl; C5-C18 cycloalkyl; C5-C18 cycloalkenyl; a radical of a saturated or unsaturated aliphatic bicyclic or tricyclic hydrocarbon of 7 to 12 carbon atoms; C2-C7alkyl or C3-C7alkenyl substituted by halogen, C1-C8alkoxy or phenoxy; C4-C12heterocycloalkyl; C4-C12heterocycloalkenyl; C7-C15 aralkyl or C4-C12heteroaralkyl, each of which is unsubstituted or substituted by C1-C4 alkyl or phenyl; or E′ is a radical of formula (VII) or (VIII)
reacting a N-oxyl amine of formula B
with a compound of formula IV or V
E′-H (IV)
H-L-H (V)
in the presence of an organic hydroperoxide and a catalytic amount of an iodide.
More specifically, present invention pertains to a process for the preparation of an amine ether of the formula A
wherein
reacting a N-oxyl amine of formula B
with a hydrocarbon of formula IV or V
E′-H (IV)
H-L-H (V)
in the presence of an organic hydroperoxide and a catalytic amount of an iodide.
In particular, present invention pertains to a process for the synthesis of a hindered amine of formula I or II
wherein
In the context of the description of the present invention, the term alkyl comprises, for example, methyl, ethyl and the isomers of propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. Examples of aryl-substituted alkyl (aralkyl) are benzyl, α-methylbenzyl or cumyl. Examples of alkoxy are methoxy, ethoxy, propoxy, butoxy, octyloxy etc. Examples of alkenyl are vinyl and especially allyl. Examples of alkylene including alkylidene are ethylene, n-propylene or 1,2-propylene.
Some examples of cycloalkyl are cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, dimethylcyclopentyl and methylcyclohexyl.
Examples of aryl are phenyl and naphthyl. Examples of substituted aryl are methyl-, dimethyl-, trimethyl-, methoxy- or phenyl-substituted phenyl.
Some examples of an aliphatic carboxylic acid are acetic, propionic, butyric, stearic acid. An example of a cycloaliphatic carboxylic acid is cyclohexanoic acid. An example of an aromatic carboxylic acid is benzoic acid. An example of a phosphorus-containing acid is methylphosphonic acid. An example of an aliphatic dicarboxylic acid is malonyl, maleoyl or succinyl, or sebacic acid. An example of a residue of an aromatic dicarboxylic acid is phthaloyl.
A group heterocycloalkyl or heterocycloalkenyl embraces one or two heteroatoms, and a group heteroaryl from one to four heteroatoms, the heteroatoms being preferably selected from the group consisting of nitrogen, sulfur and oxygen. Some examples of heterocycloalkyl are tetrahydrofuryl, pyrrolidinyl, piperazinyl and tetrahydrothienyl. Some examples of heteroaryl are furyl, thienyl, pyrrolyl, pyridyl and pyrimidinyl. C2-C12heterocycloalkyl is typically oxirane, 1,4-dioxane, tetrahydrofuran, γ-butyrolactone, ε-caprolactam, oxirane, aziridine, diaziridine, pyrrole, pyrrolidine, thiophen, furan, pyrazole, imidazole, oxazole, oxazolidine, thiazole, pyran, thiopyran, piperidine or morpholine.
An example of a monovalent silyl radical is trimethylsilyl.
Polycyclic alkyl radicals which may also be interrupted by at least one oxygen or nitrogen atom are for example adamantane, cubane, twistane, norbornane, bycyclo[2.2.2]octane bycyclo[3.2.1]octane, hexamethylentetramine (urotropine) or a group
Acyl radicals of monocarboxylic acids are, within the definitions, a residue of the formula —CO—R″, wherein R″ may stand inter alia for an alkyl, alkenyl, cycloalkyl or aryl radical as defined. Preferred acyl radicals include acetyl, benzoyl, acryloyl, methacryloyl, propionyl, butyryl, valeroyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, undecanoyl, dodecanoyl, pentadecanoyl, stearoyl. Polyacyl radicals of polyvalent acids are of the formula (—CO)n—R″, wherein n is the valency, e.g. 2, 3, 4, 5 or 6. Some preferred examples for such residues are given elsewhere.
In preferred products of the instant process, E′ is selected from the group consisting of
(C5-C6cycloalkyl)2CCN, (C1-C12alkyl)2CCN, —CH2CH═CH2, (C1-C12)alkyl-CR30—C(O)—(C1-C12)alkyl, (C1-C12)alkyl-CR30—C(O)—(C6-C10)aryl, (C1-C12)alkyl-CR30—C(O)—(C1-C12)alkoxy, (C1-C12)alkyl-CR30—C(O)-phenoxy, (C1-C12)alkyl-CR30—C(O)—N-di(C1-C12)alkyl, (C1-C12)alkyl-CR30—CO—NH(C1-C12)alkyl, (C1-C12)alkyl-CR30—CO—NH2, —CH2CH═CH—CH3, —CH2—C(CH3)═CH2, —CH2—CH═CH-phenyl,
(C1-C12)alkyl-CR30—CN,
wherein
G1 and G2 and/or G3 and G4 forming, together with the linking carbon atom, a C3-C12cycloalkyl radical, preferably form a C5-C12cycloalkyl radical, especially cyclopentylene, cyclohexylene or cycloheptylene.
G1, G2, G3 and G4 independently are preferably alkyl of 1 to 4 carbon atoms, or the adjacent radicals G1 and G2 and/or G3 and G4 together are pentamethylene. More preferably, G1, G2, G3 and G4 independently are methyl or ethyl or propyl, especially methyl or ethyl. In the products most preferred, G1 and G3 are each methyl while G2 and G4 independently are methyl, ethyl or propyl.
T usually is an organic linking group containing 2-500 carbon atoms and forming, together with the carbon atoms it is directly connected to and the nitrogen atom, a substituted, 5-, 6 or 7-membered cyclic ring structure; T is preferably a C2-C500hydrocarbon optionally containing 1-200 hetero atoms selected from nitrogen, oxygen, phosphorus, sulfur, silicon and halogen, T therein can be part of a 6-membered cyclic ring structure. More preferably, T is an organic linking group of the formula
wherein
The product of formula A most preferably corresponds to one of the formulae
wherein
The sterically hindered aminoxides, also referred to as N-oxyl educts for the instant process which include compounds of formulae B, III or IIIa, are largely known in the art; they may be prepared by oxidation of the corresponding N—H hindered amine with a suitable oxygen donor, e.g. by the reaction of the corresponding N—H hindered amine with hydrogen peroxide and sodium tungstate as described by E. G. Rozantsev et al., in Synthesis, 1971, 192; or with tert-butyl hydroperoxide and molybdenum (VI) as taught in U.S. Pat. No. 4,691,015, or obtained in analogous manner.
The preferred amount of hydrocarbon for the instant process depends to some extent on the relative number of reactive hydrogens on the hydrocarbon reactant and the hindered amine nitroxyl compound. The reaction is typically carried out with a ratio of 1 to 100 moles of hydrocarbon per mole of nitroxyl moiety with the preferred ratio being 1 to 50 moles per mole of nitroxyl moiety, and the most preferred ratio being 1 to 30 moles of hydrocarbon per mole of nitroxyl moiety.
The preferred amount of organic hydroperoxide is 1 to 20 moles per mole of nitroxyl moiety, with the more preferred amount being 1 to 5 moles of peroxide per mole of nitroxyl moiety and the most preferred amount being 1 to 3 moles of peroxide per mole of nitroxyl moiety.
The organic hydroperoxide used in the process of present invention can be of the formula R—OOH, wherein R usually is a hydrocarbon containing 1-18 carbon atoms. The organic hydroperoxide preferably is a peroxoalcohol containing 3-18 carbon atoms. R is often aliphatic, preferably C1-C12alkyl. Most preferred organic hydroperoxide is tert.butyl hydroperoxide.
The preferred amount of iodide catalyst is from about 0.0001 to 0.5, especially 0.0005 to 0.1 molar equivalent per mole of nitroxyl moiety, with a ratio of 0.001 to 0.05 moles of iodide per mole of nitroxyl moiety being the most preferred.
The reaction is preferably run at 0° to 100° C.; more preferably at 20° to 100° C., especially in the range 20-80° C.
More specifically, the instant process involves the reaction of a mixture of 1 to 100 moles of the hydrocarbon, e.g. of formula IV or V, 1 to 20 moles of organic hydroperoxide, and 0.001 mmoles to 0.5 moles of iodide catalyst per mole of N-oxyl compound, such as the compound of formula B (1 mmol is 0.001 mol). Preferably, the molar ratio of iodide catalyst per mole of N-oxyl compound is in the range from 1:100 to 1:100000, especially 1:300 to 1:100000.
E is preferably a carbon centered radical formed from a C7-C11phenylalkane or a C6-C10pyridylalkane; or C5-C12cycloalkane; or C5-C12cycloalkene; or an oxacyclohexane or oxycyclohexene; or C3-C8alkene; or C3-C8alkene substituted by phenoxy; or a benzene which is substituted by C1-C4alkyl and a further substituent selected from C1-C4alkoxy, glycidyl or glycidyloxy; or E is a radical of formula (VIII)
wherein
Important are those educts, which are pure hydrocarbons.
The educt hydrocarbon, such as compound of formula IV or V, may serve two functions both as reactant and as solvent for the reaction. The reaction can also be carried out using an inert organic or inorganic solvent. A mixture of products may result if the hydrocarbon contains non-equivalent carbon-hydrogen bonds which are reactive in the instant process. For example, cyclohexane can give only one product whereas isopentane can give three distinct reaction products.
Usually the hydrocarbon reactand, e.g. compound of formula IV or V, reacts with its most active aliphatic carbon-hydrogen bond.
A solvent may be used, especially if the hydrocarbon, such as the compound of of formula IV or V, is a solid at the temperature of the reaction or if the catalyst is not very soluble in the hydrocarbon. Inert solvents should have less active carbon-hydrogen bonds; typical inert solvents are acetonitrile, aromatic hydrocarbons like benzene, chlorobenzene, CCl4, alcohols (e.g. methanol, ethanol, ethylene glycol, ethylene glycol monomethyl ether), or, especially for reactions with activated hydrocarbons like alkylated aromats or alkenes, also alkanes like hexane, decane etc., or mixtures thereof. Inorganic solvents such as water are possible as well. The reaction can be carried out in one liquid phase or in separate phases.
Good results can be achieved when phase transfer catalysts such as quaternary ammonium or phosphonium salts are used. For example, quaternary ammonium or phosphonium halogenides such as chlorides or bromides may be employed for this purpose. The structure of the ammonium or phosphonium cation is less important; usually, quaternary ammonium or phosphonium cations contain 4 hydrocarbon residues bonded to the central nitrogen or phosphorus atom, which may be, for example, alkyl, phenylalkyl or phenyl groups. Some readily available materials are tetra-C1-C12alkylated.
The iodide catalyst may be selected from any iodide compound, including organic and inorganic iodide compounds. Examples are alkaline or alkaline earth metal iodides, or onium iodides such as ammonium or phosphonium or sulfonium iodides. Suitable metal iodides are, inter alia, those of lithium, sodium, potassium, magnesium or calcium.
Especially good results can be achieved when onium iodides are used which are soluble in organic solvents. Suitable onium iodides embrace quaternary ammonium, phosphonium or sulfonium iodides. The structure of the onium cation is less important provided the solubility in organic solvents is high enough; the latter can be increased by increasing the hydrophobicity of the hydrocarbon residues attached to the onium cation. Some readily available materials are tetra-C1-C12alkylated ammonium iodides and/or the following compounds:
In a preferred embodiment, the iodide catalyst functions the same time as a phase transfer catalyst, e.g. when a quaternary ammonium or phosphonium iodide such as tetrabutylammoniumiodide is used as catalyst. These compounds are known, many are commercially available.
The onium iodides can be generated from any other onium salt (e.g., hydroxide, sulfate, hydrogensulfate, fluoride, acetate, chloride, cyanide, bromide, nitrate, nitrite, perchlorate etc.) via insitu anion exchange using a watersoluble inorganic iodide such as alkaline or alkaline earth metal iodides, other iodine containing salts or elemental iodine. For example, commercial onium chlorides of the ALIQUAT® series may conveniently be brought into the above iodide form by in situ anion exchange.
The onium iodides can be bound to an organic or inorganic polymer backbone, rendering a homogeneous or heterogenous catalytic system.
Preferably, the pH of the aqueous phase, if present, is held between 7 and 11, especially between 9 and 10, most preferably at 9 during the reaction.
Preferred are quaternary ammonium or phosphonium iodides, especially tetraalkyl ammonium iodides.
The instant process can be run in air or in an inert atmosphere such a nitrogen or argon. The instant process can be run under atmospheric pressure as well as under reduced or elevated pressure. Elevated pressure can especially be useful in reactions with a hydrocarbon, which is gaseous under atmospheric pressure and the reaction temperature; in this case, pressure/temperature conditions are advantageous where the hydrocarbon forms a liquid phase or is at least partially dissolved in a suitable solvent.
There are several variations of the instant process. One variation involves the addition of a solution of organic hydroperoxide to a mixture of the N-oxyl hindered amine, the hydrocarbon and cosolvent (if used), and catalyst which has been brought to the desired temperature for reaction. The proper temperature may be maintained by controlling the rate of peroxide addition and/or by using a heating or cooling bath. After the hydroperoxide is added, the reaction mixture is conveniently stirred till the starting N-oxyl, e.g. compound of formula III, has disappeared or is no longer being converted to the desired product, e.g. compound of formula I and/or II. The reaction can be monitored by methods known in the art such as UV-Vis spectroscopy, thin layer chromatography, gas chromatography or liquid chromatography. Additional portions of catalyst can be added while the reaction is in progress. After the initial hydroperoxide charge has been added to the reaction mixture, more hydroperoxide can be added dropwise to bring the reaction to completion.
A second variation of the instant process is to simultaneously add separate solutions of the hydroperoxide and the nitroxyl compound to a mixture of the hydrocarbon, cosolvent (if used) and catalyst. The nitroxyl compound may be dissolved in water or the alcohol solvent used in the reaction. Some of the nitroxyl compound may be introduced into the reaction mixture prior to starting the peroxide addition, and all of the nitroxyl compound should be added prior to completing the peroxide addition.
Another variation of the instant process involves the simultaneous addition of separate solutions of the hydroperoxide and of the aqueous or alcohol solution of the catalyst to a mixture of the nitroxyl compound, hydrocarbon, and cosolvent (if used). Some of the metal may be introduced into the reaction mixture prior to starting the peroxide addition.
Still another variation of the instant process is the simultaneous addition of separate solutions of the hydroperoxide, of the aqueous or alcohol solution of the nitroxyl compound, and of an aqueous or alcohol solution of the catalyst to the hydrocarbon and cosolvent (if used). A portion of the nitroxyl compound and/or catalyst may be introduced into the reaction mixture prior to starting the hydroperoxide addition. All of the nitroxyl compound should be added prior to completing the hydroperoxide addition.
At the end of the reaction, the residual hydroperoxide should be carefully decomposed prior to the isolation of any products.
Examples for compounds which can be obtained advantageously with the process of present invention are those of formulae 1-28:
wherein in formulas (1) to (15):
Preferably, the reaction site in the compound E-H or H-L-H is an activated carbon-hydrogen bond, whose carbon, for example, is linked to an electron pushing functional group or a functional group able to stabilize the radical formed after cleavage of the carbon-hydrogen bond. Electron withdrawing groups, if present in E-H or H-L-H, are preferably not directly linked to the reactive site.
Products of the present process can be employed with advantage for stabilizing organic material against the damaging effect of light, oxygen and/or heat, especially for stabilizing synthetic organic polymers or compositions containing them. They are notable for high thermal stability, substrate compatibility and good persistence in the substrate.
The compounds made by the instant process are particularly effective in the stabilization of polymer compositions against harmful effects of light, oxygen and/or heat; they are also useful as initiators or regulators for radical polymerization processes which provide homopolymers, random copolymers, block copolymers, multiblock copolymers, graft copolymers and the like, at enhanced rates of polymerization and enhanced monomer to polymer conversions.
Of particular interest is the use of products of the present process as stabilizers in synthetic organic polymers, for example a coating or a bulk polymer or article formed therefrom, especially in thermoplastic polymers and corresponding compositions as well as in coating compositions. Thermoplastic polymers of most importance in present compositions are polyolefines and their copolymers, thermoplastic polyolefin (TPO), thermoplastic polyurethan (TPU), thermoplastic rubber (TPR), polycarbonate, such as in item 19 above, and blends, such as in item 28 above. Of utmost importance are polyethylene (PE), polypropylene (PP), polycarbonate (PC) and polycarbonate blends such as PC/ABS blends, as well as in acid or metal catalyzed coating compositions.
In general the products of present invention may be added to the material to be stabilized in amounts of from 0.1 to 10%, preferably from 0.01 to 5%, in particular from 0.01 to 2% (based on the material to be stabilized). Particular preference is given to the use of the novel compounds in amounts of from 0.05 to 1.5%, especially from 0.1 to 0.5%. Where compounds of present invention are used as flame retardants, dosages are usually higher, e.g. 0.1 to 25% by weight, mainly 0.1 to 10% by weight of the organic material to be stabilized and protected against inflammation.
Used in polymerizable compositions as a polymerization regulator or initiator, preferably the regulator/initiator compound is present in an amount of from 0.01 mol-% to 30 mol-%, more preferably in an amount of from 0.1 mol-% to 20 mol-% and most preferred in an amount of from 0.5 mol-% to 10 mol-% based on the monomer or monomer mixture.
The following examples are for illustrative purposes only and are not to be construed to limit the instant invention in any manner whatsoever. Percentages given are usually percent by weight if not otherwise indicated. Abbreviations used:
To a stirred mixture of 5 g (32 mmol) 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO), 34 g (320 mmol) of ethylbenzene and 0.12 g (0.32 mmol) of tetrabutylammoniumiodide, 6.2 g (48 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 30 minutes. The temperature is maintained at 60° C. for 25 minutes until all of the TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 61 g of an aqueous solution of Na2SO3 (10%) until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with ethylbenzene. The combined organic phases are washed with brine, dried over MgSO4, filtered, and the solvent is distilled off on a rotary-evaporator. The crude product is purified by flash-chromatography (silica gel, hexane:ethylacetate 9:1), yielding 5 g (60% of theory) of a yellow oil. Analysis required for C17H27NO (261.41): C, 78.11%, H, 10.41%, N, 5.36%; found: C, 78.04%, H, 10.46%, N, 5.26%. 1H-NMR (CDCl3), δ (ppm): 0.66 (broad s, 3H), 1.03-1.52 (m, 15H), 1.48 (d, J=8 Hz, 3H), 4.78 (q, J=8 Hz, 1H), 7.21-7.33 (m, 5H).
Example 1 is repeated except that 32 mmol of 2,2,6,6-Tetramethylpiperidine-N-oxide are replaced by the equivalent amount of 2,2,6,6-Tetramethylpiperidine-4-one-N-oxide, yielding a compound of formula
A stirred mixture of 0.5 g (3.2 mmol) TEMPO, 1.14 g (6.4 mmol) of 2-(4-ethyl-phenoxymethyl)-oxirane, 0.0118 g (0.032 mmol) of tetrabutylammoniumiodide and 0.62 g (4.8 mmol) of t-butylhydroperoxid (70% aqueous solution) is brought to 60° C. The temperature is maintained at 60° C. for 4 hours until all of the TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 20 g of a 10% aqueous Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with ethylbenzene. The combined organic phases are passed through a plug of silica gel, washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 0.9 g of a colorless oil. Quantitative HPLC-analysis reveals a product-concentration of 65% w/w, corresponding to an overall yield of 54.8%. 1H-NMR (CDCl3), δ (ppm; 2-(4-Ethyl-phenoxymethyl)-oxirane not shown): 0.63 (broad s, 3H), 1.01-1.56 (m, 15H), 1.45 (d, J=8 Hz, 3H), 2.75-2.76 (m, 1H), 2.89-2.91 (m, 1H), 3.34-3.36 (m, 1H), 3.95-3.99 (m, 1H), 4.17-4.21 (m, 1H), 4.73 (q, J=8 Hz, 1H), 6.84-6.88 (m, 2H), 7.21-7.26 (m, 2H).
To a stirred mixture of 5 g (32 mmol) TEMPO, 39.1 g (320 mmol) of phenetole and 0.12 g (0.32 mmol) of tetrabutylammoniumiodide, 12.37 g (96 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 60 minutes. The temperature is maintained at 60° C. for 21 hours until all TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 121 g of a 10% aqueous Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered. and the solvent is distilled off on a rotary-evaporator. The crude product is purified by flash-chromatography (silica gel, Hexane/Ethylacetate 9/1), yielding 4.6 g (51.8% of theory) of a slightly yellow oil. Analysis required for C17H27NO2 (277.41): C, 73.61%, H, 9.81%, N, 5.05%; found: C, 73.15%, H, 9.89%, N, 4.95%. 1H-NMR (CDCl3), δ (ppm): 1.13 (s, 3H), 1.16 (s, 3H), 1.19 (s, 6H), 1.30-1.69 (m, 6H), 1.47 (d, J=8 Hz, 3H), 5.58 (q, J=8 Hz, 1H), 6.92-6.96 (m, 1H), 7.01-7.03 (m, 2H), 7.24-7.28 (m, 2H).
To a stirred mixture of 50 mmol 4-propoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 41.1 g (500 mmol) of cyclohexene and 0.18 g (0.5 mmol) of tetrabutylammoniumiodide, 7.4 g (58 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 55° C. within 30 minutes. The reaction mixture is cooled down to 25° C. and stirred with 63 g of an aqueous 20% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are passed through a plug of silica gel and washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator. The crude product is purified by distillation, yielding the title product.
by Hydrogenation of the Product of Example 5
A mixture of 4 mmol) of the product of Example 5 and 0.2 g Pd on charcoal (10%) in 10 ml of methanol is hydrogenated at 25° C. and 4 bar of hydrogen. Filtration and evaporation of the solvent yields the title product as a slightly orange oil.
To a stirred mixture of 5.5 g (35 mmol) TEMPO, 10.5 g (70 mmol) of phenylacetic acid methyl ester and 0.13 g (0.35 mmol) of tetrabutylammoniumiodide, 6.75 g (52.5 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 25 minutes. The temperature is maintained at 60° C. for 46 hours. The reaction mixture is cooled down to 25° C. and stirred with 66 g of a 10% aqueous Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with ethylbenzene. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator. The crude product is purified by flash-chromatography (silica gel, hexane:ethylacetate 9:1), yielding 6 g (56% of theory) of the title product as a white crystalline solid, mp 85° C.-87° C. Analysis required for C18H27NO3 (305.42): C, 70.79%, H, 8.91%, N, 4.59%; found: C, 70.60%, H, 9.13%, N, 4.53%. 1H-NMR (CDCl3), δ (ppm): 0.72 (s, 3H), 1.07 (s, 3H), 1.14 (s, 3H), 1.23 (s, 3H), 1.28-1.58 (m, 6H), 3.65 (s, 3H), 5.21 (s, 1H), 7.27-7.35 (m, 3H), 7.43-7.45 (d-like, 2H).
To a stirred mixture of 6.8 g (32 mmol) of 2,6-diethyl-2,3,6-trimethyl-piperidin-4-one-N-oxide, 34 g (320 mmol) of ethylbenzene and 0.12 g (0.32 mmol) of tetrabutylammoniumiodide, 6.2 g (48 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 30 minutes. The temperature is maintained at 60° C. for 13 hours, after which another 6.2 g of t-butylhydroperoxid and 0.12 g of tetrabutylammoniumiodide are added. The temperature is maintained at 60° C. for another 24 hours, cooled down to 25° C. and stirred with 120 g of a 10% aqueous Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with ethylbenzene. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator. The crude product is purified by flash-chromatography (silica gel, hexane:Ethylacetate 9:1), yielding the title product as a yellow oil. Analysis required for C20H31NO2 (317.48): C, 75.67%, H, 9.84%, N, 4.41%; found: C, 74.01%, H, 9.76%, N, 4.30%. 1H-NMR (CDCl3), δ (ppm, O—CH only): 4.83 (p-like, 1H).
To a stirred mixture of 6.4 g (25 mmol) of 3,3,8,8,10,10-hexamethyl-1,5-dioxa-9-aza-spiro[5.5]undecane-N-oxide, 8.9 g (50 mmol) of 2-(4-ethyl-phenoxymethyl)-oxirane and 0.09 g (0.25 mmol) of tetrabutylammoniumiodide, 3.4 g (37.5 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 30 minutes. The temperature is maintained at 60° C. for 17.6 hours. The reaction mixture is cooled down to 25° C. and stirred with 47 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 12.2 g of a brownish oil partially crystallizing at low temperature. The title product is obtained as an off-white solid, mp 106° C.-110° C. Analysis required for C25H39NO5 (433.59): C, 69.25%, H, 9.07%, N, 3.23%; found: C, 68.24%, H, 9.04%, N, 2.87%. 1H-NMR (CDCl3), δ (ppm): 0.63 (br s, 3H), 0.93 (br s, 3H), 0.95 (br s, 3H), 1.14 (br s, 3H), 1.30 (br s, 6H), 1.45-1.48 (m, 4H), 1.53-1.60 (m, 1H), 2.05-2.09 (d-like, 1H), 2.16-2.20 (d-like, 1H), 2.75-2.76 (m, 1H), 2.89-2.91 (m, 1H), 3.34-3.36 (m, 1H), 3.45 (s, 4H), 3.94-3.99 (m, 1H), 4.18-4.21 (m, 1H), 4.74 (q, J=8 Hz, 1H), 6.84-6.87 (d-like, 2H), 7.22-7.25 (d-like, 2H).
A stirred mixture of 1.42 g (2.5 mmol) of N,N′-dibutyl-6-chloro-N,N′-bis-(2,2,6,6-tetramethyl-piperidin-4-yl-N-oxide)-[1,3,5]-triazine-2,4-diamine, 4.2 g (50 mmol) cyclohexane, 0.018 g (0.05 mmol) tetrabutylammoniumiodide and 1.93 g (15 mmol) t-butylhydroperoxid (70% aqueous solution) is brought to 68° C. The temperature is maintained at 68° C. for 22 hours. The reaction mixture is cooled down to 25° C. and stirred with 18.9 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 1.1 g g of a reddish solid. Purification by flash-chromatography (silica gel, hexane:ethylacetate 9:1) yields the title product as a white solid, mp 86° C.-90° C. Analysis required for C41H74ClN7O2 (732.55): C, 67.23%, H, 10.18%, Cl, 4.84%, N, 13.38%; found: C, 67.16%, H, 10.08%, Cl, 4.91%, N, 12.86%. 1H-NMR (CDCl3), δ (ppm): 0.88-0.96 (m, 6H), 1.05-1.4 (m, 42H), 1.45-1.60 (m, 6H), 1.63-1.80 (m, 8H), 2.0-2.1 (m, 4H), 3.25-3.35 (m, 4H), 3.55-3.65 (m, 2H), 4.9-5.1 (m, 2H).
To a stirred mixture of 8 g (35 mmol) of propionic acid-2,2,6,6-tetramethylpiperidin-4-yl-N-oxide ester, 29.5 g (350 mmol) cyclohexane and 0.13 g (0.35 mmol) of tetrabutylammoniumiodide, 13.5 g (105 mmol) of t-butylhydroperoxid (70% aqueous solution) are added at 60° C. within 20 minutes. The temperature is maintained at 60° C. for 2.8 hours. The reaction mixture is cooled down to 25° C. and stirred with 132 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 10 g of a reddish oil. Purification by flash-chromatography (silica gel, hexane:ethylacetate 9:1) yields the title product as a yellowish oil. Analysis required for C18H33NO3 (311.47): C, 69.41%, H, 10.68%, N, 4.50%; found: C, 69.32%, H, 10.57%, N, 4.40%. 1H-NMR (CDCl3), δ (ppm): 1.09 (t, J=8 Hz, 3H), 1.10-1.26 (m, 17H), 1.52-1.57 (m, 3H), 1.74-1.84 (m, 4H), 2.03-2.05 (m, 2H), 2.28 (q, J=8 Hz, 2H), 3.56-3.62 (m, 1H), 4.98-5.06 (m, 1H).
To a stirred mixture of 8.95 g (30 mmol) 8,10-diethyl-3,3,7,8,10-pentamethyl-1,5-dioxa-9-aza-spiro[5.5]undecane-N-oxide, 24.6 g (300 mmol) cyclohexene and 0.11 g (0.3 mmol) tetrabutylammoniumiodide are added at 65° C. within 20 minutes 5.8 g (45 mmol) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 65° C. for 15 minutes until all of the N-oxide has reacted. The reaction mixture is cooled down to 25° C. and stirred with 57 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 10.5 g (92% of theory) of a slightly orange oil. Purification by Flash-Chromatography (silica gel, Hexane/Ethylacetate 8/2) affords 9.7 g (85% of theory) the title compound as a viscous, colourless oil. Analysis required for C23H41NO3 (379.58): C, 72.78%, H, 10.89%, N, 3.69%; found: C, 72.61%, H, 10.65%, N, 3.66%.
To a stirred mixture of 9.1 g (30 mmol) 8,10-Diethyl-3,3,7,8,10-pentamethyl-1,5-dioxa-9-aza-spiro[5.5]undecane-N-oxide, 31.9 g (300 mmol) Ethylbenzene and 0.11 g (0.3 mmol) Tetrabutylammoniumiodide are added at 60° C. within 25 minutes 5.8 g (45 mmol) t-Butylhydroperoxid (70% aqueous solution). The temperature is maintained at 65° C. for 15 minutes until all of the N-oxide has reacted. The reaction mixture is cooled down to 25° C. and stirred with 57 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-Butylhydroperoxide. The aqueous phase is then separated and washed with Ethylbenzene. The combined organic phases are washed with Brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 12.4 g (102% of theory) of a slightly yellow oil. Purification by Flash-Chromatography (silica gel, Hexane/Ethylacetate 9.5/0.5) affords 10 g (82.6% of theory) of the title compound as a viscous, colourless oil. Analysis required for C25H41NO3 (403.61): C, 74.40%, H, 10.24%, N, 3.47%; found: C, 74.29%, H, 10.47%, N, 3.36%.
Preparation of the compound of Example 1 with the catalyst Bu4Nl generated in situ from Bu4NCl/Nal; yield determination by HPLC.
To a stirred mixture of 0.5 g (3.2 mmol) 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO), 3.8 g (35.6 mmol) ethylbenzene, 0.0092 g (0.032 mmol) tetrabutylammoniumchloride and 0.0048 g (0.032 mmol) sodium iodide dissolved in 1 ml water are added at 50° C. 0.62 g (4.8 mmol) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 50° C. for 80 minutes, after which a sample is withdrawn and analyzed by quantitative HPLC. The yield is 78%.
Preparation of the compound of Example 12 using immobilized onium iodide. This allows the catalyst be filtered off after the reaction.
To a stirred mixture of 8.95 g (30 mmol) 8,10-diethyl-3,3,7,8,10-pentamethyl-1,5-dioxa-9-aza-spiro[5.5]undecane-N-oxide, 24.6 g (300 mmol) cyclohexene and 0.3 g (0.3 mmol) tributylmethylammonium iodide bound to polystyrene (1 meq iodide/g) are added at 70° C. within 35 minutes 5.8 g (45 mmol) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 70° C. for 18.5 hours until all of the nitroxide has reacted. The reaction mixture is cooled down to 25° C. and the catalyst filtered off. The filtrate is stirred with 57 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 10.7 g (94% of theory) of the title product as a slightly orange oil.
To a stirred mixture of 0.769 g (3 mmol) 3,3,8,8,10,10-hexamethyl-1,5-dioxa-9-aza-spiro[5.5]undecane-N-oxide, 1.6 g (9 mmol, 3 eq) 2-(4-ethyl-phenoxymethyl)-oxirane, 0.046 g (0.3 mmol, 0.1 eq) biphenyl (internal standard) and 0.03 mmol (0.01 eq) onium iodide are added at 60° C. 0.579 g (4.5 mmol, 1.5 eq) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 60° C. Samples are withdrawn and analyzed by quantitative HPLC.
Using Bu4Nl as onium iodide yields 82% of theory after 22 h (nitroxide conversion: 97%). Good results are also achieved when the amount of 2-(4-ethyl-phenoxymethyl)-oxirane is reduced to 2, 1.5 or 1 eq.; or when using 1 eq. of 2-(4-ethyl-phenoxymethyl)-oxirane, the catalyst is replaced by the equivalent amount of Ph4Pl or Oct3MeNl, or the amount of Bu4Nl is increased to 0.15 mmol (0.05 eq.).
To a stirred mixture of 0.829 g (3 mmol) benzoic acid-2,2,6,6-tetramethyl-piperidin-4-yl-N-oxid ester, 2.53 g (30 mmol, 10 eq) cyclohexane, 0.046 g (0.3 mmol, 0.1 eq) biphenyl (internal standard) and 0.03 mmol (0.01 eq) onium iodide are added at 60° C. 0.579 g (4.5 mmol, 1.5 eq) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained constant. Samples are withdrawn after 22 h and analyzed by quantitative HPLC. Results are given in the tables below:
Good results are also achieved when the amount onium iodide catalyst or the amount of tert.butyl hydroperoxide is doubled.
Abbreviations:
Me methyl, Et ethyl, Pr n-propyl, iPr iso-propyl, Bu n-butyl, Hex n-hexyl, Oct n-octyl, Ph phenyl, Bz benzyl, Py 1-pyridinium
Using a wide variety of catalysts, the present process effectively converts the N-oxide into the desired product, yielding only low levels of by-products.
To a stirred mixture of 8.3 g (30 mmol) benzoic acid-2,2,6,6-tetramethyl-piperidin-4-yl-N-oxid ester, 25.4 g (300 mmol) cyclohexane and 0.14 g (0.3 mmol) tetraphenylphosphonium iodide are added at 80° C. within 30 minutes 11.6 g (90 mmol) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 80° C. for 19.3 hours. The reaction mixture is cooled down to 25° C. and stirred with aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is then separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 9 g of a red oil. Purification by flash-chromatography (silica gel, hexane/ethylacetate 9/1) affords 6.8 g (63% of theory) of the product as a viscous, colorless oil. Analysis required for C22H33NO3 (359.51): C, 73.50%, H, 9.25%, N, 3.90%; found: C, 72.68%, H, 9.39%, N, 3.85%.
To a stirred mixture of 7.7 g (45 mmol) triacetoneamine-N-oxide, 37.3 g (450 mmol) cyclohexene and 0.17 g (0.45 mmol) tetrabutylammonium iodide are added at 60° C. within 1 hour 17.4 g (135 mmol) t-butylhydroperoxid (70% aqueous solution). The temperature is maintained at 60° C. for 21.7 hours. After further addition of catalyst (0.24 g, 0.45 mmol trioctylmethylammonium iodide) and t-butylhydroperoxide (17.4 g, 135 mmol) the temperature is maintained another 24 hours. The reaction mixture is then cooled down to 25° C. and stirred with aqueous 10% Na2SO3 solution until the disappearance of excess t-butylhydroperoxide. The aqueous phase is separated and washed with cyclohexane. The combined organic phases are washed with brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 11.7 g of an orange oil. Purification by flash-chromatography (silica gel, hexane/ethylacetate 9/1) affords the title product as a colorless oil. Analysis required for C15H25NO2 (251.37): C, 71.67%, H, 10.02%, N, 5.57%; found: C, 71.33%, H, 10.03%, N, 5.78%.
To a stirred mixture of 5 g (32 mmol) TEMPO, 52.5 g (320 mmol) 2-Phenylethylacetate and 0.12 g (0.32 mmol) Tetrabutylammoniumiodide are added at 60° C. within 25 minutes 12.37 g (96 mmol) t-Butylhydroperoxid (70% aqueous solution). The temperature is maintained at 60° C. for 18.67 hours until all of the TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 121 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-Butylhydroperoxide. The aqueous phase is then separated and washed with Ethylbenzene. The combined organic phases are washed with Brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator. The crude product is purified by flash-chromatography (silica gel, Hexane/Ethylacetate 9/1), yielding the title product as a colorless oil. Analysis for C19H29NO3 (319.45): C, 71.44%, H, 9.15%, N, 4.38%; found: C, 71.36%, H, 9.20%, N, 4.21%. 1H-NMR (CDCl13), δ (ppm): 0.66 (broad s, 3H), 1.08-1.60 (m, 15H), 1.95 (s, 3H), 4.23-4.30 (m, 1H), 4.57-4.61 (m, 1H), 4.91 (t, J=8 Hz, 1H), 7.28-7.37 (m, 5H).
To a stirred mixture of 7.8 g (50 mmol) TEMPO, 41.1 g (500 mmol) Cyclohexene and 0.18 g (0.5 mmol) Tetrabutylammoniumiodide are added at 55° C. within 30 minutes 7.4 g (58 mmol) t-Butylhydroperoxid (70% aqueous solution). The reaction mixture is cooled down to 25° C. and stirred with 63 g of an aqueous 20% Na2SO3 solution until the disappearance of excess t-Butylhydroperoxide. The aqueous phase is then separated and washed with Cyclohexane. The combined organic phases are passed through a plug of silica gel and washed with Brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator. The crude product is purified by distillation, yielding 8 g (67.4% of theory) of an orange oil (bp 62° C.-65° C./0.04 mbar). Analysis required for C15H27NO (237.39): C, 75.90%, H, 11.46%, N, 5.90%; found: C, 75.69%, H, 11.99%, N 5.75%. 1H-NMR (CDCl3), δ (ppm): 1.13-2.07 (m, 24H), 4.24 (br s, 1H), 5.77-5.81 (m, 1H), 5.91-5.95 (m, 1H).
A mixture of 0.95 g (4 mmol) 1-(Cyclohex-2-enyloxy)-2,2,6,6-tetramethyl-piperidine and 0.2 g Pd on charcoal (10%) in 10 ml Methanol is hydrogenated at 25° C. and 4 bar Hydrogen. Filtration and evaporation of the solvent yields the title product as a slightly orange oil. Analysis for C15H29NO (239.40): C, 75.26%, H, 12.21%, N, 5.85%; found: C, 74.53%, H, 12.07%, N, 5.90%. 1H-NMR (CDCl3), δ (ppm): 1.12-1.39 (m, 19H), 1.40-1.65 (m, 7H), 1.74 (br s, 1H), 2.04 (br s, 1H), 3.58 (m, 1H).
A mixture of the crude product from example 21 (10.87 g, 91.6% of theory) and 2.4 g Pd on charcoal (10%) in 120 ml Methanol is hydrogenated as described in example 22. Filtration and evaporation of the solvent yields 6.8 g of a slightly yellow oil. Analysis required for C15H29NO (239.40): C, 75.26%, H, 12.21%, N, 5.85%; found: C, 74.53%, H, 12.07%, N 5.90%. 1H-NMR (CDCl3), δ (ppm): 1.12-1.39 (m, 19H), 1.40-1.65 (m, 7H), 1.74 (br s, 1H), 2.04 (br s, 1H), 3.58 (m, 1H).
To a stirred mixture of 7.3 g (32 mmol) Propionic acid-2,2,6,6-tetramethylpiperidin-4-yl-N-oxide ester, 26.3 g (320 mmol) Cyclohexene and 0.12 g (0.32 mmol) Tetrabutylammoniumiodide are added at 55° C. within 25 minutes 6.2 g (48 mmol) t-Butylhydroperoxid (70% aqueous solution). The temperature is maintained at 55° C. for 5 minutes until all of the TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 61 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-Butylhydroperoxide. The aqueous phase is then separated and washed with Cyclohexane. The combined organic phases are passed through a plug of silica gel and washed with Brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 8.7 g (87.9% of theory) of the above product as a slightly orange oil. Analysis required for C18H31NO3 (309.45): C, 69.87%, H, 10.10%, N, 4.53%; found: C, 69.36%, H, 10.03%, N, 4.45%. 1H-NMR (CDCl3), δ (ppm): 1.12 (t, J=8 Hz, 3H), 1.20-1.26 (m, 12H), 1.52-1.58 (m, 4H), 1.73-2.1 (m, 6H), 2.29 (q, J=8 Hz, 2H), 4.23 (m, 1H), 5.05 (m, 1H), 5.79-5.82 (m, 1H), 5.90-5.94 (m, 1H).
A mixture of CG40-1201 (1 g, 3.19 mmol) and 0.17 g Pd on charcoal (10%) in 30 ml Hexane is hydrogenated as described in example 6. Filtration and evaporation of the solvent yields 0.9 g (90.6% of theory) of a slightly yellow oil. Analysis required for C18H33NO3 (311.47): C, 69.41%, H, 10.68%, N, 4.50%; found: C, 69.20%, H, 10.76%, N, 4.42%. 1H-NMR (CDCl3), δ (ppm): 1.09 (t, J=8 Hz, 3H), 1.10-1.26 (m, 17H), 1.52-1.57 (m, 3H), 1.74-1.84 (m, 4H), 2.03-2.05 (m, 2H), 2.28 (q, J=8 Hz, 2H), 3.56-3.62 (m, 1H), 4.98-5.06 (m, 1H).
To a stirred mixture of 14.2 g (25 mmol) of N,N′-Dibutyl-6-chloro-N,N′-bis-(2,2,6,6-tetramethyl-piperidin-4-yl-N-oxide)-[1,3,5]-triazine-2,4-diamine, 41 g (500 mmol) Cyclohexene and 0.18 g (0.5 mmol) Tetrabutylammoniumiodide are added at 57° C. within 30 minutes 9.7 g (75 mmol) t-Butylhydroperoxid (70% aqueous solution). The temperature is maintained at 57° C. for 5 minutes until all of the TEMPO has reacted. The reaction mixture is cooled down to 25° C. and stirred with 63 g of an aqueous 10% Na2SO3 solution until the disappearance of excess t-Butylhydroperoxide. The aqueous phase is then separated and washed with Cyclohexane. The combined organic phases are washed with Brine, dried over MgSO4, filtered and the solvent distilled off on a rotary-evaporator, yielding 14.5 g (79.6% of theory) of a slightly yellow solid. Crystallization from Acetone/Hexane yields 12.2 g (67%) of a white solid, mp 83° C.-87° C. Analysis required for C41H70ClN7O2 (728.51): C, 67.60%, H, 9.69%, Cl, 4.87%, N, 13.46%; found: C, 67.27%, H, 9.63%, Cl, 4.97%, N, 13.34%. 1H-NMR (CDCl3), δ (ppm): 0.89-0.96 (m, 6H), 1.22-1.32 (m, 26H), 1.49-1.56 (m, 12H), 1.73-1.78 (m, 8H), 1.89-2.04 (m, 6H), 3.31-3.32 (m, 4H), 4.24-4.26 (m, 2H), 4.99-5.06 (m, 2H), 5.80-5.83 (m, 2H), 5.92-6.02 (m, 2H).
| Number | Date | Country | Kind |
|---|---|---|---|
| 01811143.5 | Nov 2001 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP02/12957 | 11/19/2002 | WO |
