CN110691767A

CN110691767A - Process for preparing compounds and mixtures having antidegradants and antifatigue effects

Info

Publication number: CN110691767A
Application number: CN201880038136.8A
Authority: CN
Inventors: M.A.布恩; D.L.小菲尔兹; F.伊纳茨-胡佛
Original assignee: Eastman Chemical Co
Current assignee: Eastman Chemical Co
Priority date: 2017-06-09
Filing date: 2018-05-17
Publication date: 2020-01-14
Also published as: EP3634938A1; WO2018226375A1

Abstract

Disclosed is a process for preparing an antidegradant compound of formula I wherein a p-phenylenediamine of formula IV is reacted with a diol of formula II to obtain a mixture comprising the antidegradant compound.

Description

Process for preparing compounds and mixtures having antidegradants and antifatigue effects

Technical Field

The present invention relates generally to a process for preparing compounds and mixtures having antidegradants and antifatigue efficacy useful as additives to vulcanized rubber articles, vulcanizable elastomeric formulations, lubricants, fuels, fuel additives and other compositions requiring such efficacy or in compositions that may themselves be used as compositions to impart such efficacy.

Background

Many materials, such as plastics, elastomers, lubricants, cosmetics, and petroleum products (e.g., hydraulic fluids, oils, fuels, and oil/fuel additives for automotive and aerospace applications) are susceptible to degradation upon prolonged exposure to light, heat, oxygen, ozone, repeated mechanical action, and the like. Thus, compounds and compositions that exhibit efficacy as antidegradants are well known in the art. For example, U.S. patent No. 8,987,515 discloses aromatic polyamines that can be used to inhibit oxidative degradation, particularly in lubricant compositions. U.S. patent application publication No. 2014/0316163 discloses antioxidant macromolecules purportedly having improved solubility in many commercially available oils and lubricants.

Antidegradants that can be used to make articles formed from elastomers, plastics, etc., require very specific combinations of qualities that can be difficult to achieve. While antidegradants must have a significant commercially acceptable efficacy, they must also exhibit this efficacy over long periods of time associated with the use of the article, particularly at the exposed surfaces of the article where degradation by environmental factors such as light, oxygen and ozone occurs primarily. Just as it is important to protect surface exposed components, the efficacy of protecting the embedded components of the composite material from oxidative aging and repeated mechanical action is also of critical importance. Antidegradants must achieve these effects without negatively impacting the efficacy or desirable characteristics of other additives in the final article. Furthermore, antidegradants that provide or improve mechanical fatigue life after an article has been put into service, aged by oxidative aging, or aged by exposure to ozone are highly appreciated, as these antidegradants will inherently improve the useful mechanical service life of the article. Thus, elastomeric articles that undergo repeated mechanical bending, stretching, or compression during use would greatly benefit from this discovery.

Articles, particularly tires, formed from general purpose elastomers such as natural rubber are particularly susceptible to degradation by oxygen and ozone. As discussed in U.S. patent No. 2,905,654, the effect of oxygen degradation on rubber is different from the effect of ozone degradation on rubber; however, both of these effects can be detrimental to tire performance, appearance, and life expectancy. Fatigue and crack growth are also of particular concern, particularly for steel belt edge regions and tire sidewalls that are subject to significant stresses and tensile forces when bent, whether inflated, partially inflated, and over the life of the tire. U.S. patent No. 8,833,417 describes an antioxidant system which is said to increase long term resistance to fatigue and crack growth compared to known antioxidants as discussed immediately below.

Materials having efficacy as antidegradants are well known in the art for tire applications and are commercially available. For example, N, N' -disubstituted-p-phenylenediamines (e.g., Santoflex, tradename, available from Eastman Chemical Company)^®Those sold) are generally favored by many tire manufacturers for this purpose. EP patent application publication No. EP 3147321 a1 discloses a rubber composition, a tire, an amine compound and an anti-aging agent, and particularly a rubber composition purportedly suitable for tread rubber or sidewall rubber of a tire. As government regulations, market demands, and consumer expectations drive the rubber industry toward lighter weight tires to improve fuel efficiency and conserve natural resource feedstocks, there remains a continuing need for improved antidegradants, and methods of making the same, that exhibit (i) multiple efficacy against fatigue, crack growth, and various degradation mechanisms; (ii) increased efficacy, especially at lower concentrations; and (iii) a longer efficacy period when compared to current commercial materials.

Disclosure of Invention

In a first aspect, the present invention relates to compounds represented by formula I:

wherein each R is independently selected from (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive); (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkaryl groups; or wherein R is selected from substituted or unsubstituted alkyl having C =0 to 3 (inclusive);

wherein X¹、X²、X³And X⁴Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or wherein X¹、X²、X³And X⁴Each independently hydrogen or methyl;

wherein R is¹、R²、R³And R⁴Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or wherein R is¹、R²、R³And R⁴Each independently selected from butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R²With R³And R⁴One of which may optionally be bridged by a polymethylene group;

wherein when C =0 in R, the group R is combined¹R²With a combination radical R³R⁴The same; and is

Wherein when C = 1 in R, R¹、R²、R³And R⁴Each is hydrogen.

In a second aspect, the present invention relates to compositions comprising a compound represented by formula I as shown above, and methods of making the same. In a further aspect, the present invention relates to antidegradant compositions and mixtures comprising the antidegradant compounds of the present invention.

In a further aspect, the present invention relates to antidegradant compositions comprising the compounds of the invention.

In another aspect, the present invention relates to lubricant compositions comprising the compounds of the present invention.

In yet another aspect, the present invention relates to vulcanizable elastomer formulations comprising the compounds of the present invention.

In yet another aspect, the present invention relates to a vulcanized elastomeric rubber article having at least one component formed from the vulcanizable elastomeric formulation of the present invention.

In another aspect, the present invention relates to a process for preparing antidegradant compounds, corresponding to formula I as shown above and as further described herein, as well as mixtures containing them. In this aspect, a p-phenylenediamine is reacted with a diol to obtain a mixture comprising an antidegradant compound; wherein the p-phenylenediamine corresponds to formula IV:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is independently hydrogen or methyl;

the diol corresponds to formula II:

wherein each R is independently selected from: (a) (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive); (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkaryl groups; or (b) a substituted or unsubstituted alkyl having C =0 to 3 (inclusive); and is

Wherein R is¹And R³Each independently selected from: (a) alkyl, aryl, alkaryl groups and hydrogen; or (b) butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups to form cycloalkyl groups;

the antidegradant compound is according to formula I:

wherein each R is independently selected from: (a) (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive); (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkaryl groups; or (b) a substituted or unsubstituted alkyl having C =0 to 3 (inclusive);

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or wherein R is¹And R³Each independently selected from butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups;

wherein when C =0 in R, R¹And R³The same; and is

Wherein when C = 1 in R, R¹And R³Each is hydrogen.

The compounds of the present invention have surprisingly shown efficacy as antidegradants and antifatigue agents and are therefore particularly useful for imparting resistance to crack growth, degradation, and many manifestations thereof in a variety of applications. When used as a component in vulcanizable elastomer formulations forming vulcanized rubber articles, and more particularly in vehicle tires and components thereof, the compounds of the present invention have shown a particularly desirable and surprising combined efficacy against oxidative degradation, ozonated degradation, and resistance against fatigue and crack growth, which is superior to the combinations heretofore achieved by prior art materials. Further advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the spirit and scope of the present disclosure.

Detailed Description

As used herein, the following terms or phrases are defined as follows:

an "antidegradant" refers to a material that inhibits degradation (caused by, for example, heat, light, oxidation, and/or ozonation) or its manifestation of a composition, formulation, or article to which it is added or applied.

By "anti-fatigue agent" is meant a material that, after being applied in place for a period of time (whereby the composition, formulation or article is subjected to thermal, oxidative, ozone and mechanical degradation forces), improves the flex fatigue resistance of the composition, formulation or article to which it is added or applied.

"antioxidant" refers to a material that inhibits oxidative degradation of a composition, formulation or article to which it is added or applied.

By "antiozonant" is meant a material that inhibits ozone exposure degradation of a composition, formulation or article to which it is added or applied.

"elastomer" means any polymer that can be stretched to at least twice its original length under low stress after vulcanization (or crosslinking) and at room temperature, and will recover under force to about its original length upon immediate release of the stress, including but not limited to rubber.

"vulcanizable elastomer formulation" means a composition that comprises an elastomer and is capable of being vulcanized when subjected to vulcanization conditions.

In a first aspect, the present invention relates to a compound represented by the formula:

wherein each R is independently selected from (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive); (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkaryl groups;

wherein X¹、X²、X³And X⁴Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; wherein R is¹、R²、R³And R⁴Each independently selected fromAlkyl, aryl, alkylaryl groups and hydrogen, and R¹And R²With R³And R⁴One of which may optionally be bridged by a polymethylene group; wherein when C =0 in R, the group R is combined¹R²With a combination radical R³R⁴The same; and, wherein when C = 1 in R, R¹、R²、R³And R⁴Each is hydrogen.

In certain embodiments according to formula I, R may be selected from substituted or unsubstituted alkyl groups of C =0 to 3 (inclusive). R may thus be such that C =0, C = 1, C = 2, or C = 3. In embodiments, C may be equal to 0 to 3 carbons, or 1 to 2 carbons, or 1 to 3 carbons, inclusive.

Thus, when R is absent such that C =0, then the carbon atoms depicted on both sides of the R group are directly bonded to each other to form an ethylene group. Alternatively, R may be a single carbon where C = 1, i.e. R may be a methylene group, such that a propylene group is bonded to each adjacent nitrogen atom. R may also represent an alkyl group having two carbon atoms, wherein C = 2, i.e. an ethylene group, such that a butylene group is bonded to each adjacent nitrogen atom. In yet another embodiment, R may be such that C may be equal to 3, i.e., a propylene group, such that a pentylene group is bonded to each adjacent nitrogen atom, or may be branched such that adjacent carbons are bonded to the carbon adjacent to the R group depicted, while the third carbon is bonded to only one of the two carbons bonded to those adjacent to the R group, i.e., an isopropylene group.

For the R group, we note that when C =0 in R, the group R is combined¹R²With a combination radical R³R⁴The same is true. Furthermore, we note that when C = 1 in R, then R¹、R²、R³And R⁴Each is hydrogen.

We also note that, according to certain aspects of formula I, X¹、X²、X³And X⁴May each independently be hydrogen or methyl. Those skilled in the art will understand that when X is¹、X²、X³And X⁴The nitrogen molecule to which it is bonded, each being hydrogen, is thus a secondary amine, known to be desirable in certain known or proposed mechanisms of antioxidant action. Alternatively, certain advantages may be realized when the compounds of the present invention are methylated compounds (forming methylated derivatives as shown in example 14), such as improved cure characteristics and fatigue resistance properties.

According to certain embodiments of formula I, R¹、R²、R³And R⁴Each independently selected from butyl, propyl, ethyl, methyl or hydrogen. Thus, in various embodiments, R¹、R²、R³And R⁴May be all hydrogen, or may be all methyl, or may be all ethyl, propyl or butyl, or may be a mixture of any of these. For example, R¹And R²One of which may be methyl and the other hydrogen, and R³And R⁴One of which may be methyl and the other hydrogen.

In an alternative embodiment according to formula I, R¹And R²With R³And R⁴One of which may be optionally bridged by a polymethylene group to form a cycloalkyl group. Thus, in various embodiments, the compounds of the present invention may comprise a substituted or unsubstituted cycloalkyl group, such as cyclobutane, cyclopropane, or cyclohexane, or cycloheptane, or cyclooctane, wherein R is¹、R²、R³And R⁴Two of which may contain a methylene group attached to a cycloalkyl group, or may each constitute the carbon of the cyclic alkyl group itself. Non-limiting cycloalkyl groups that may be present in the compounds of formula II include cyclohexane and cyclohexanedimethanol. Diols useful in forming such compounds containing a cyclic alkyl group thus also include, but are not limited to, cyclohexanediol, cyclohexanedimethanol. Similarly, dicarbonyl compounds useful for obtaining such compounds include cyclohexanedione and cyclohexanedialdehyde.

Non-limiting examples of compounds of the present invention include N, N' - (ethane-1, 2-diyl) bis (N-phenyl-benzene-1, 4-diamine); n, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine); n, N' - (octane-1, 8-diyl) bis (N-phenyl-benzene-1, 4-diamine); n, N' - (1, 4-phenylenebis (methylene)) bis (N-phenyl-1, 4-diamine); n, N' - (1, 3-phenylenebis (methylene)) bis (N-phenyl-1, 4-diamine); n, N '- (1, 4-phenylenebis (ethane-1, 1-diyl)) bis (N-phenylphenyl-1, 4-diamine) and N, N' - (1, 3-phenylenebis (ethane-1, 1-diyl)) bis (N-phenylphenyl-1, 4-diamine). These are represented schematically as follows, each with reference to a respective written embodiment(s) of the manufacturing method described below:

preferred examples of compounds according to formula I of the present invention include N, N '- (ethane-1, 2-diyl) bis (N-phenyl-1, 4-diamine) and N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine) as depicted above.

In another aspect, the present invention relates to a process for preparing antidegradant compounds, corresponding to formula I as shown above and as further described herein, and mixtures containing them. In this aspect, a p-phenylenediamine is reacted with a diol to obtain a mixture comprising an antidegradant compound, wherein the p-phenylenediamine corresponds to formula IV:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein X is hydrogen or methyl;

the diol corresponds to formula II:

the antidegradant compound is according to formula I:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is hydrogen or methyl;

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or wherein R is¹And R³Each is selected from butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups;

wherein, when C =0 in R, R¹And R³Are the same as, and

wherein, when C = 1 in R, R¹And R³Is hydrogen.

The present invention therefore relates to a process for the preparation of a compound according to formula I according to the following reaction scheme:

wherein each R is independently selected from (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive); (ii) substituted or unsubstituted aryl; and (iii) substituted and unsubstituted alkaryl groups; or wherein each R is independently selected from substituted or unsubstituted alkyl having C =0 to 3 (inclusive);

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is hydrogen or methyl; r¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or wherein R is¹And R³Each independently selected from butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups;

wherein when C =0 in R, R¹And R³Are identical to each other

Wherein when C = 1 in R, R¹And R³Each is hydrogen.

Suitable p-phenylenediamines corresponding to formula IV useful in accordance with the present invention include those wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; particularly those in which X is independently hydrogen or methyl, and particularly 4-amino-p-phenylenediamine.

Suitable diols corresponding to formula II useful according to the present invention include those wherein each R is independently selected from alkyl groups having C =0 to 12 (inclusive) or 0 to 3 (inclusive); substituted or unsubstituted aryl; and substituted and unsubstituted alkaryl groups. Suitable diols also include those wherein R¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; or butyl, propyl, ethyl, methyl or hydrogen, and wherein R¹And R³Those bridged by polymethylene groups. Thus, specific diols suitable for use according to the present invention include ethylene glycol, propylene glycol, butylene glycol, 1, 8-octanediol, and the like.

According to the present invention, a p-phenylenediamine corresponding to formula IV is reacted with a diol corresponding to formula II to obtain the desired antidegradant compound represented by formula I. This reaction can be described as reductive amination by hydrogen (borne hydrogen reduction), which can be accomplished by contacting p-phenylenediamine and a diol in the presence of a homogeneous or heterogeneous metal catalyst. The reaction may be carried out in the presence or absence of a solvent. Examples of useful solvents include, but are not limited to, cyclohexane, toluene, xylene, mesitylene, ethylene glycol, t-butyl methyl ether, and tetrahydrofuran. These solvents may be used alone or in combination as a mixture.

The amount of solvent used, if any, may be based on the amount of diol such that the weight% of solvent is from about 1% to about 75%, or from 25% to 40%, relative to the weight of diol present.

Examples of useful metal catalysts include those based on ruthenium, iridium, platinum, palladium, tin, iron, Al₂O₃And TiO₂The ligand-functionalized homogeneous catalyst or solid-supported heterogeneous catalyst of (a). The amount of catalyst used can be based on the amount of diol of formula II such that the wt% of catalyst is from about 0.005 wt% to about 10 wt% of active catalyst, based on the weight of diol present, excluding water content. The temperature of the reaction may be, for example, 50 ℃ up to 300 ℃.

Each of the above parameters can affect reaction kinetics, conversion, and selectivity. It is therefore preferred to select the reaction conditions such that the time required for completion is from 0.5 hours to 12 hours, most preferably from 1 to 3 hours.

Thus, the compounds of the present invention can be prepared from polyol starting materials by a hydrogen self-transfer procedure using homogeneous or heterogeneous catalysts (for a general description of the mechanism, see for example Guillena et al,Chem. Rev.2010,110, 1611). The compounds of interest can also be prepared from polycarbonyl starting materials using heterogeneous transition metal catalysts in the presence of hydrogen.

Precursors of the compounds of the present invention, the compounds of the present invention and their methods of preparation are illustrated by the following examples, which are not intended to limit the spirit or scope of the invention in any way.

Example 1: preparation of the precursor (N, N ', N, N ') -N, N ' - (ethane-1, 2-diylidene) bis (N-phenylphenyl-1, 4-diamine)

4-ADPA (127 g, 689 mmol) was dissolved in EtOH (absolute ethanol) in a 1L three-necked round-bottomed flask with overhead stirrer(200 proof), 363 mL). Glyoxal (40% aqueous solution, 50g, 345 mmol) was added to a mixture of EtOH: water (1: 1, 100 mL) in a separate beaker. The glyoxal solution was then added dropwise to the reaction mixture over a period of 50 minutes, during which time red solids began to form. The mixture was stirred for an additional 20 minutes, after which time water (150 mL) was added all at once to further precipitate a dark red solid. The slurry was stirred overnight. After the solid was recovered by filtration and washed with additional water, the red solid was placed in a vacuum oven (with nitrogen purge) at 50 ℃ overnight (131.57 g, 98% yield).¹H NMR（300 MHz, DMSO-d6） δ 8.49（bs, 2H）, 8.47（s, 2H）, 7.38（m, 4H）, 7.31-7.28（m, 4H）, 7.16-7.11（m, 8H）, 6.92-6.89（m, 2H）。

Example 2: preparation of N, N' - (ethane-1, 2-diyl) bis (N-phenyl-1, 4-diamine)

DIBAL-H (122 g, 25 wt.% in toluene) was slowly transferred via cannula into a 1L round bottom flask containing THF (102 mL). Diimine 1 (20.0 g, 50.2 mmol) is then added carefully at ambient temperature. After the addition was complete, the mixture was heated to 60 ℃ and allowed to react for 19.25 hours. The reaction was then cooled to about 5-10 ℃ using an ice-water bath, at which point a saturated solution of sodium potassium tartrate was added dropwise until the reaction mixture formed a gel. At this point, 250mL of sodium potassium tartrate solution was added rapidly followed by 500mL of EtOAc. The biphasic mixture was stirred vigorously overnight. The mixture was then transferred to a 1-L separatory funnel and the layers were subsequently separated. With Na₂SO₄The organic was dried. The mixture was then filtered through a short plug of silica gel (short plug) and the filter cake was rinsed with a small amount of EtOAc and THF. The product was isolated as a light brown powder (17.3 g, 86% yield). ICP analysis: 86ppm of aluminum. T is_m= 167.09℃.¹H NMR（500 MHz, DMSO-d6） δ 7.50（bs, 2H）,7.10（m, 4H）, 6.91（m, 4H）, 6.79（m, 4H）, 6.62-6.58（m, 6H）, 5.35（bs, 2H）, 3.21（m, 4H）。

Example 3: alternative preparation of N, N' - (ethane-1, 2-diyl) bis (N-phenyl-1, 4-diamine)

The procedure is as follows: 20g of water-wet Raney nickel (Raney Ni) slurry was transferred to a Parr bottle. 400g of Dimethylformamide (DMF) and 200g of EtOH were then added. 200g of bisimine 1 are added to the catalyst/solvent mixture. The vial was placed in a Parr shaker apparatus and purged three times with nitrogen. By H₂The vessel was purged three times with gas and then pressurized to 40 psig. Stirring was started and the contents were heated to an internal set point of 48 ℃. Once the reaction reaches this temperature, H is reacted₂The pressure was adjusted to 50 psig. The reaction was stirred for 2.5 hours and then allowed to cool to ambient temperature over 1 hour. The catalyst was removed by passing the mixture through a column of celite, rinsing the bottle and filter cake with a minimum of DMF/EtOH (110 g DMF, 140g EtOH). The homogeneous mixture was transferred to a 1L round bottom flask with a magnetic stir bar. 750g of water are added via a constant pressure dropping funnel over a period of 40 minutes with vigorous stirring. The precipitated solid was filtered through a1 micron glass fiber disc and washed with 2.5L of water. The solid was transferred to a 1L Erlenmeyer flask and was in about 750mL H₂Stir with stir bar for 4 hours. The solid was filtered again and further H was added₂And O washing. Placing the brown solid with N₂Purged 60 ℃ vacuum oven and allowed to dry overnight. Separation yield: 179g, 90% yield, 99% selectivity. T is_m= 167.09℃.¹H NMR（500 MHz, DMSO-d6） δ 7.50（bs, 2H）, 7.10（m, 4H）, 6.91（m, 4H）, 6.79（m, 4H）, 6.62-6.58（m, 6H）, 5.35（bs, 2H）, 3.21（m,4H）。

Example 4: preparation of the precursor (N, N ') -N, N' - (butane-2, 3-divalenyl) bis (N-phenylphenyl-1, 4-diamine)

4-ADPA (128 g, 689 mmol) was dissolved in EtOH (anhydrous ethanol (200 proof), 375 mL) in a 1L three-necked round bottom flask with overhead stirrer. Diacetyl (30.0 g, 348 mmol) was added dropwise over a period of 20 minutes via a constant pressure addition funnel. After 13 hours, heptane (375 mL) was added in about 50mL portions over a 40 minute period (slow heptane addition helped to reduce caking). The mixture was stirred vigorously for 15 minutes and then filtered. The solid was washed with additional heptane and then dried in a 50 ℃ vacuum oven with a nitrogen purge (67.45 g, 46% yield).¹H NMR（500 MHz,DMSO-d6） δ 8.13（bs, 2H）, 7.24（m, 4H）, 7.12（m, 4H）, 7.06（m, 4H）, 6.82-6.79（m,6H） 2.17（s, 6H）。

Example 5: alternative preparation of 4,4- (((2E,3E) -butane-2, 3-divalenyl) bis (azepan-1-yl-1-ylidene)) bis (N-phenylaniline)

The procedure is as follows: 4-ADPA (690 g, 3.8 mol) was dissolved in 1800g EtOH and 780g heptane in a 3L three-necked round bottom flask with overhead stirrer. Then 5.02g phosphoric acid (85%) was added. Diacetyl (150 g, 1.7 mol) was added dropwise over a period of 5 minutes via a constant pressure addition funnel. The mixture was heated to 50 ℃. After 24 hours, the reaction was allowed to cool to ambient temperature. The yellow-green solid was filtered and washed with 1L of saturated NaHCO₃Wash, then twice with water (1L). The filter cake is washed with 1L of isopropanol and subsequently with 1L of heptane. The solid was dried in a 50 ℃ vacuum oven with a nitrogen purge (569 g, 78% yield).¹H NMR（500 MHz, DMSO-d6） δ 8.13（bs, 2H）, 7.24（m, 4H）, 7.12（m, 4H）, 7.06（m, 4H）,6.82-6.79（m, 6H） 2.17（s, 6H）。

Example 6: preparation of N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine)

In a 1L round bottom flask, LiAlH₄(7.40 g, 1995 mmol) was carefully added to THF (162 mL). Diimine 3 (20.4 g, 48.7 mmol) was added carefully to the solution. After the addition was complete, the reaction was refluxed for 4 hours. After this time, the mixture was cooled using an ice-water bath and then carefully quenched by dropwise addition of water (25 mL) followed by dropwise addition of 15% NaOH (50 mL). An additional 150mL of water was added to the mixture and then stirred overnight. After filtration, the brown liquid was concentrated under reduced pressure using a rotary evaporator. The resulting brown solid was washed with heptane and then dried in a vacuum oven at 45 ℃ with a nitrogen purge (16.5 g, 80% yield). (¹H NMR indicated a mixture of meso compound and the corresponding isomer). T is_m=175.02℃.¹H NMR（300 MHz, CDCl3） δ 7.24（m, 4H）, 7.00（m, 4H）, 6.85-6.75（m,6H）, 6.70-6.55（m, 4H）, 5.40（bs, 2H）, 3.75-3.50（m, 4H）, 1.25（m, 6H）。

Example 7: alternative preparation of N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine)

The procedure is as follows: 2.5g of 5% Pt-C (50% water wet) were transferred to a Parr bottle. Then 75g of EtOAc were added and 25g of bisimine 3 were added to the catalyst/solvent mixture. The vial was placed in a Parr shaker apparatus and purged three times with nitrogen. By H₂The vessel was purged three times with gas and then pressurized to 50 psig. Stirring was started. The reaction was stirred for 3 hours. The catalyst was removed by passing the mixture through a column of diatomaceous earth (celite). Volatiles were removed under reduced pressure using a rotary evaporator. The product was isolated as a viscous liquid which solidified upon cooling to ambient temperature. 22g was recovered with 86% yield and 99% selectivity. (¹H NMR indicated a mixture of meso compound and the corresponding isomer).¹H NMR (500 MHz, DMSO-d 6) delta 7.49 (bs, 4H, major isomer), 7.47 (bs, 2H, minor isomer), 7.10 (m, 4)H) 6.92-6.86 (m, 4H), 6.79 (m, 4H), 6.64-6.55 (m, 6H), 5.07 (d, 2H, major isomer), 4.92 (d, 2H, minor isomer), 3.51 (m, 4H), 1.15 (d, 6H, major isomer), 1.11 (d, 6H, minor isomer).

Example 8: alternative preparation of N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine)

The procedure is as follows: acetoin (5.0 g, 57 mmol) was transferred to a 250mL round bottom flask with a magnetic stir bar. 4-ADPA (21 g, 110 mmol) was then added to the flask followed by EtOH (75 g). Amberlyst 15 (dry, 500 mg) was added to the mixture, which was then stirred at 50 ℃ for 70 hours. The mixture was then allowed to cool to ambient temperature and stirred for an additional 5 hours. The yellow solid/catalyst was filtered and washed with some heptane. NMR analysis of the intermediate indicated the desired enediamine.¹HNMR (500 MHz, DMSO-d 6) delta 8.13 (bs, 2H), 7.24 (m, 4H), 7.12 (m, 4H), 7.07 (m, 4H), 6.81 (m, 6H), 2.17 (s, 6H). 3.5g of the enediamine/catalyst mixture and 500mg of 5% Pt-C (50% water-wet) were transferred to a Parr bottle. Then 50g EtOAc and 25g EtOH were added. The vial was placed in a Parr shaker apparatus and purged three times with nitrogen. By H₂The vessel was purged three times with air and then pressurized to 50 psig. Stirring was started and the reaction was stirred for 2.5 hours. The catalyst was removed by passing the mixture through a column of diatomaceous earth (celite). Volatiles were removed under reduced pressure using a rotary evaporator. (¹H NMR indicated a mixture of meso compound and the corresponding isomer).¹H NMR (500 MHz, DMSO-d 6) Δ 7.49 (bs, 4H, major isomer), 7.47 (bs, 2H, minor isomer), 7.10 (m, 4H), 6.92-6.86 (m, 4H), 6.79 (m, 4H), 6.64-6.55 (m, 6H), 5.07 (d, 2H, major isomer), 4.92 (d, 2H, minor isomer), 3.51 (m, 4H), 1.15 (d, 6H, major isomer), 1.11 (d, 6H, minor isomer).

Example 9: preparation of a mixture of the N, N '- (ethane-1, 2-diyl) bis (N-phenylphenyl-1, 4-diamine) Compound 2 and N-1, 3-dimethylbutyl-N' -phenyl-p-phenylenediamine (6 PPD)

A mixture of 3.0g of bisimine 1, 75mL of methyl isobutyl ketone (MIBK), and 0.10g of 3% Pt-C (sulfided) catalyst was charged to a 300mL Parr autoclave. The system was purged three times with nitrogen by pressurizing to 100psig and releasing. After nitrogen purge, the system was pressurized to 400psig with hydrogen and heated to 125 ℃ at an agitation rate of 1800 rpm. The hydrogen pressure was maintained at 400psig throughout the reaction. The system was allowed to react for 5.5 hours at which point no further hydrogen consumption was detected. The autoclave was cooled to room temperature. HPLC-MS analysis showed that the product mixture contained approximately equal amounts of diamine product (Compound 2) and 6 PPD.

Example 10: preparation of N, N' - (octane-1, 8-diyl) bis (N-phenyl-1, 4-diamine)

1, 8-octanediol (10.0 g, 68.4 mmol), 4-ADPA (25.2 g, 137 mmol) and RuCl₂(PPh₃)₃(3.28 g, 3.42 mmol) was transferred to a 250mL thick walled round bottom flask with Teflon screw cap. Add a magnetic stir bar. The flask was sealed and then heated to 135 ℃. After 2.5 hours at this temperature, the reaction was subsequently cooled to ambient temperature. The resulting monoclinic blue solid was dissolved in THF (150 mL). The solution was then filtered through a silica gel column and rinsed with heptane: EtOAc (1: 1). Volatiles were stripped off under reduced pressure. The solid was rinsed with a little toluene and dried in a vacuum oven at 50 ℃ under nitrogen purge. XRF analysis of the solid showed 1,000ppm ruthenium contamination. After multiple passes over a silica column and activated carbon, compound 5 was isolated as a light gray solid (1.81 g, 2.65% yield). XRF analysis = 95ppm ruthenium. T is_m= 129.13℃.¹HNMR（500 MHz, CDCl3） δ 7.46（bs, 2H）, 7.09（m, 4H）, 6.88（m, 4H）, 6.77（m, 4H）,6.60（m, 2H）, 6.53（m, 4H）, 5.23（at, J = 5.5 Hz, 2H）, 2.97（m, 4H）, 1.56（m, 4H）,1.43-1.28（m, 8H）。

Example 11: preparation of the precursor (N, N, N, N) -N, N' - (1, 4-phenylenebis (methane-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine)

Terephthalaldehyde (10.0 g, 74.6 mmol), 4-ADPA (32.9 g, 178 mmol) and p-TSA (709 mg, 3.73 mmol) were transferred to a 500mL three-necked round bottom flask equipped with a magnetic stir bar and thermocouple. Toluene (298 mL) was added. A Dean-Stark apparatus with a condenser was placed on the flask and the mixture was heated to reflux. After 10 hours, about 3mL of water was collected. The mixture was allowed to cool to ambient temperature. The resulting green solid was filtered and then washed with a little toluene followed by heptane. After drying in a 50 ℃ vacuum oven with a nitrogen purge, compound 6 (34.8 g, Quant.) was isolated as a crystalline green solid.¹H NMR（500 MHz, DMSO-d6） δ 8.74（s, 2H）, 8.35（bs, 2H）,8.03（s, 4H）, 7.35（m, 4H）, 7.27（m, 4H）, 7.13（m, 8H）, 6.87（m, 2H）。

Example 12: preparation of N, N' - (1, 4-phenylenebis (methylene)) bis (N-phenylbenzene-1, 4-diamine)

DIBAL-H (101 g, 25 wt.% in toluene) was slowly transferred via cannula into a 1L round bottom flask containing THF (86 mL). Diimine 6 (20.0 g, 42.9 mmol) is then carefully added at ambient temperature. After the addition was complete, the mixture was heated to 60 ℃ and the reaction was allowed to proceed for 19 hours (after 3 hours of reaction time, additional DIBAL-H (20.0 g, 25% by weight in toluene) was added then the reaction was cooled to about 5 ℃ to 10 ℃ using an ice water bath at which point a saturated solution of sodium potassium tartrate was added dropwise until the reaction mixture formed a gel at which point 275mL of sodium potassium tartrate solution was added rapidly followed by 500mL of EtOAc. The biphasic mixture was stirred vigorously overnight. The mixture was then transferred to a 1-L separatory funnel and the layers were subsequently separated. The organics (and some suspended solids) were then washed with 10% NaOH (250 mL). The combined aqueous components were extracted with EtOAc (400 mL). The organics were combined and washed with water (200 mL). With Na₂SO₄The organic was dried. The mixture was then filtered and the volatiles were removed under reduced pressure. The solid was washed with 10% NaOH (125 mL) followed by water. The solid was then placed in a flask with a stir bar and stirred vigorously in the presence of additional water. After filtration, the solid was then stirred vigorously in heptane (200 mL). The solid was filtered and washed with some additional heptane. The light gray solid was placed in a vacuum oven at 45 ℃ with a nitrogen purge (17.45 g of isolated product). ICP analysis: 397ppm of aluminum. The solid was redissolved in EtOAc: THF (1: 1). The mixture was passed through a short column of silica gel. The column was washed with additional EtOAc, THF. The volatiles were then removed under reduced pressure. The solid was collected by filtration and removed from the flask with heptane assistance. After drying in a vacuum oven overnight (15.2 g, 75% yield), the solid was re-analyzed using ICP. ICP analysis: 13ppm of aluminum. T is_m= 165.34℃.¹H NMR（500 MHz, DMSO-d6） δ7.47（bs, 2H）, 7.33（s, 4H）, 7.08（m, 4H）, 6.85（m, 4H）, 6.79（m, 4H）, 6.77（m,4H）, 6.59（m, 2H）, 6.55（m, 4H）, 5.91（at, J = 5.0 Hz, 2H）, 4.21（d, J = 6.0 Hz,4H）。

Example 13: preparation of the precursor (N, N ') -N, N' - (1, 3-phenylenebis (methane-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine)

Isophthalaldehyde (10.0 g, 74.6 mmol), 4-ADPA (27.5 g, 149 mmol) and p-TSA (709 mg, 3.73 mmol) were transferred to a 500mL three-necked round bottom flask equipped with a magnetic stir bar and a thermocouple. Toluene (149 mL) was added. The Dean-Stark apparatus with condenser was placed on the flask and the mixture was heated to reflux (during warming, there was a green solid)Precipitated but re-dissolved upon further heating). After 2 hours, about 3mL of water was collected. The mixture was allowed to cool to ambient temperature. Heptane (300 mL) was added to the flask and the contents stirred for an additional 45 minutes. The solid was collected by filtration and then washed with NaHCO₃The solid was washed with saturated solution, EtOH, water and then final EtOH wash. After drying, the solid was triturated with toluene (400 mL) and then filtered again. The resulting residue was rinsed with a little EtOAc. The filtrate was concentrated under reduced pressure to give a yellow solid, which was dried in a 50 ℃ vacuum oven with a nitrogen purge (24.7 g, 70.9% yield).¹H NMR（500 MHz, DMSO-d6） δ 8.77（s, 2H）, 8.47（t, J = 1.7 Hz, 1H）, 8.32（s, 2H）, 8.02（dd, J = 1.6,7.6 Hz, 2H）, 7.64（t, J = 7.6 Hz, 1H）, 7.34（m, 4H）, 7.27（m, 4H）, 7.13（m, 8H）,6.86（m, 2H）。

Example 14: preparation of N, N' - (1, 3-phenylenebis (methylene)) bis (N-phenylbenzene-1, 4-diamine)

DIBAL-H (98.0 g, 25 wt.% in toluene) was slowly transferred via cannula into a 1L round bottom flask containing THF (106 mL). Diimine 8 (24.7 g, 52.8 mmol) is then added carefully at ambient temperature. After the addition was complete, the mixture was heated to 60 ℃ and allowed to react for 17.5 hours. The reaction was then cooled to about 5-10 ℃ using an ice-water bath, at which point a saturated solution of sodium potassium tartrate was added dropwise until the reaction mixture formed a gel. At this point, 650mL of sodium potassium tartrate solution was added quickly followed by 500mL of EtOAc. The biphasic mixture was stirred vigorously overnight. The mixture was then transferred to a 1-L separatory funnel and the layers were subsequently separated. With Na₂SO₄The organic was dried. The mixture was then filtered through a short column of silica gel and the filter cake was rinsed with a small amount of EtOAc and THF. The product was isolated as a light brown powder (21.5 g, 86% yield). T is_m= 103.92℃.¹H NMR（500 MHz, DMSO-d6） δ 7.47（bs, 2H）, 7.41（t, J = 1.6 Hz, 1H）, 7.27（m,4H）, 7.08（m, 4H）, 6.87（m, 4H）, 6.78（m, 4H）, 6.62-6.56（m, 6H）, 5.92（t, J = 6.0Hz, 2H）, 4.22（d, J = 6.0 Hz, 4H）。

Example 15: preparation of the precursor (N, N ', N, N ') -N, N ' - (1, 4-phenylenebis (ethan-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine)

1, 4-diacetylbenzene (50.0 g, 310 mmol), 4-ADPA (128 g, 690 mmol) and p-TSA (4.37 g, 23.1 mmol) were transferred to a 3L four-necked round bottom flask equipped with an overhead stirrer and thermocouple. Toluene (750 mL) was added. A Dean-Stark apparatus with a condenser was placed on the flask and the mixture was heated to reflux (a green solid precipitated during warming but redissolved upon further heating). After 7 hours, about 10mL of water was collected. The mixture was allowed to cool to ambient temperature. The solid was collected by filtration and then washed with NaHCO₃The solid was washed with saturated solution, water and then EtOH. After drying in a 50 ℃ vacuum oven with a nitrogen purge, the product was isolated as a green crystalline solid (139.1 g, 91% yield).¹H NMR（500 MHz, CDCl3） δ 8.08（bs, 6H）, 7.23（m, 4H）, 7.12（m, 4H）, 7.06（m, 4H）, 6.80（m, 6H）, 2.33（s, 6H）。

Example 16: preparation of N, N' - (1, 4-phenylenebis (ethane-1, 1-diyl)) bis (N-phenylphenyl-1, 4-diamine)

DIBAL-H (134 g, 25 wt.% in toluene) was slowly transferred via cannula into a 1L round bottom flask. THF (81 mL) was then added slowly. Diimine 10 (20.0 g, 40.4 mmol) is then added carefully at ambient temperature. After the addition was complete, the mixture was heated to 60 ℃ and allowed to react for 25 hours. The reaction was then cooled to about 5-10 ℃ using an ice-water bath, at which point sodium potassium tartrate was added dropwise to saturate the reactionSolution until the reaction mixture formed a gel. At this point, 500mL of potassium sodium tartrate solution was added rapidly followed by 500mL of EtOAc. The biphasic mixture was stirred vigorously overnight. The mixture was then transferred to a 1-L separatory funnel and the layers were subsequently separated. The organics were washed with 10% NaOH solution (110 mL) and then water (200 mL. times.2). With Na₂SO₄The organic was dried. The mixture was then filtered. The solid was suspended in heptane (about 250 mL) and stirred vigorously. The solid was collected by filtration and subsequently dried in a 50 ℃ vacuum oven with a nitrogen purge. The product was isolated as a tan powder (17.8 g, 88% yield). ICP analysis: 11ppm of aluminum.¹H NMR（500 MHz, DMSO-d6） δ7.41（d, J = 4.0 Hz, 2H）, 7.32（bs, 4H）, 7.06（m, 4H）, 6.80（m, 4H）, 6.74（m, 4H）,6.58（m, 2H）, 6.48（m, 4H）, 5.81（m, 2H）, 4.39（m, 2H）, 1.39（d, J = 6.5 Hz, 6H）。

Example 17: preparation of the precursor (N, N ', N, N ') -N, N ' - (1, 3-phenylenebis (ethan-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine)

1, 3-diacetylbenzene (30.0 g, 185 mmol), 4-ADPA (77.0 g, 184 mmol) and p-TSA (2.62 g, 13.9 mmol) were transferred to a 3L four-necked round bottom flask equipped with an overhead stirrer and thermocouple. Toluene (450 mL) was added. A Dean-Stark apparatus with a condenser was placed on the flask and the mixture was heated to reflux. After 8 hours, about 6.1mL of water was collected. The mixture was allowed to cool to ambient temperature. The solid was collected by filtration and then washed with NaHCO₃The solid was washed with saturated solution, water and then EtOH. After drying in a 50 ℃ vacuum oven with a nitrogen purge, 12 was isolated as a green crystalline solid (41.0 g, 45% yield).¹H NMR（500 MHz, DMSO-d6） δ 8.59（m, 2H）, 8.10（dd, J =1.8, 7.8 Hz, 2H）, 8.07（bs, 2H）, 7.12（m, 4H）, 7.59（t, J = 8.0 Hz, 1H）, 7.22（m,4H）, 7.12（m, 4H）, 7.05（m, 4H）, 6.79（m, 6H）, 2.34（s, 6H）。

Example 18: n, N' - (1, 3-phenylenebis (ethane-1, 1-diyl)) bis (N-phenyl-1, 4-diamine)

DIBAL-H (99.0 g, 25 wt.% in toluene) was slowly transferred via cannula into a 1L round bottom flask containing THF (99.0 mL) cooled using an ice-water bath. Diimine 12 (24.5 g, 49.4 mmol) is then added carefully at ambient temperature. After the addition was complete, the mixture was heated to 60 ℃ and allowed to react for 17.5 hours. The reaction was then cooled to about 5-10 ℃ using an ice-water bath, at which point a saturated solution of sodium potassium tartrate was added dropwise until the reaction mixture formed a gel. At this point, 300mL of sodium potassium tartrate solution was added rapidly followed by 300mL of EtOAc. The biphasic mixture was stirred vigorously overnight. The mixture was then transferred to a 1-L separatory funnel and the layers were subsequently separated. The aqueous layer was extracted with additional EtOAc (250 mL). Combine the organics and use Na₂SO₄And (5) drying. After filtration, the volatiles were removed under reduced pressure. The solid was then dried in a 50 ℃ vacuum oven with a nitrogen purge. The product was isolated as a tan powder (18.7 g, 76% yield).¹H NMR（500 MHz,DMSO-d6） δ 7.41（m, 2H）, 7.37（bs, 1H）, 7.21（m, 3H）, 7.05（m, 4H）, 6.79（m, 4H）,6.73（m, 4H）, 6.58（m, 2H）, 6.48（m, 4H）, 5.80（m, 2H）, 1.39（at, J = 6.5 Hz, 6H）。

Example 19: n-methylated mixtures of N-phenyl-N- (1- (4- (1- ((4- (phenylamino) phenyl) amino) ethyl) phenyl) ethyl) benzene-1, 4-diamine

As part of the test to confirm that the methylated derivative of Compound 11 is also an effective antidegradant within the scope of the present invention, Compound 11 (51.2 g, 103 mmol) was placed in a 1L two-necked round bottom flask with an overhead stirrer,and then dissolved in acetone (0.50M, 206 mL). Dimethyl sulfate (26.0 g, 206 mmol) was added all at once to the mixture. NaOH (10.34 g, 258 mmol) was dissolved in H₂O (10.6 g) and then added all at once. The reaction was stirred for 24 hours and volatiles were removed under reduced pressure. The brown residue was dissolved in EtOAc (250 mL) and water (250 mL). The layers were separated. The aqueous component was extracted with additional EtOAc (100 mL). Combine organics and use MgSO₄And (5) drying. After filtration, the volatiles were removed under reduced pressure, showing the product as a light brown solid (50.3 g recovered).¹H NMR indicated a mixture of compounds of the invention, wherein each compound is represented by the formula identified above as "14".

The compounds of the present invention can also be synthesized from polycarbonyl starting materials by catalytic reductive alkylation processes and involve heterogeneous transition metal catalysts in the presence of hydrogen. Examples of the method are provided below.

Example 20: preparation of N, N' - (1, 4-phenylenebis (ethane-1, 1-diyl)) bis (N-phenylphenyl-1, 4-diamine)

A mixture of 6.8g of 4-aminodiphenylamine (4-ADPA), 3.0g of 1, 4-diacetylbenzene, 75mL of anhydrous ethanol, 0.6g of sulfided 3% Pt/C catalyst, and 1g of 1% phosphoric acid was charged to a 300mL Parr autoclave. The system was purged three times with nitrogen by pressurizing to 100psig and releasing. After nitrogen purge, the system was heated to 150 ℃ and then pressurized with hydrogen at an agitation rate of 1800rpm and maintained at 400 psig. The system was allowed to react for 120 minutes at which time no further hydrogen consumption could be detected.

The autoclave was cooled to room temperature and the mixture containing the dark white solid was analyzed. HPLC-MS analysis indicated complete conversion of 4-ADPA. The same analysis indicated a white solid as the desired product N, N' - (1, 4-phenylenebis (ethane-1, 1-diyl)) bis (N-phenyl-1, 4-diamine).

Example 21: preparation of N, N' - (1, 3-phenylenebis (ethane-1, 1-diyl)) bis (N-phenylphenyl-1, 4-diamine)

A mixture of 6.8g of 4-aminodiphenylamine (4-ADPA), 3.0g of 1, 3-diacetylbenzene, 75mL of anhydrous ethanol, 0.6g of sulfided 3% Pt/C catalyst, and 1g of 1% phosphoric acid was charged to a 300mL Parr autoclave. The system was purged three times with nitrogen by pressurizing to 100psig and releasing. After nitrogen purge, the system was heated to 150 ℃ and then pressurized with hydrogen at an agitation rate of 1800rpm and maintained at 400 psig. The system was allowed to react for 120 minutes at which time no further hydrogen consumption could be detected.

The autoclave was cooled to room temperature and the light brown solution was analyzed. HPLC-MS analysis of the solution showed that the desired product N, N' - (1, 3-phenylenebis (ethane-1, 1-diyl)) bis (N-phenyl-1, 4-diamine) was the major product and a small amount of by-product was generated due to the incorporation of only one 4-ADPA molecule into 1, 3-diacetylbenzene.

To demonstrate the multiple efficacy of the compounds of the present invention, an analytical procedure was performed to measure oxygen degradation inhibition, ozone degradation inhibition, and fatigue and crack growth inhibition. To demonstrate antioxidant efficacy, the Oxidative Induction Time (OIT) of selected examples was evaluated. OIT is measured according to a procedure performed in a Differential Scanning Calorimeter (DSC), and one of ordinary skill in the art uses OIT to predict the thermal-oxidation properties of a material. In this procedure, the sample is fixed in a sample chamber and heated to a preselected temperature (150 ℃ for the present application) under a nitrogen atmosphere. Oxygen was then introduced into the sample chamber and the length of time before degradation began (as seen by the onset of the endothermic process in the DSC trace) was measured. N- (1, 3-dimethylbutyl) -N '-phenyl-p-phenylenediamine (6 PPD) and N- (1, 4-dimethylpentyl) -N' -phenyl-p-phenylenediamine (7 PPD) (known rubber antidegradant additives, available under the trademark Santoflex, were also tested as controls^®OIT available from Eastman Chemical Company). The results are listed in the following table:

table 1:

oxidation Induction Time (OIT) measured at 150 deg.C

Examples	OIT (minutes) at 150 ℃
		Without additives	4
6-PPD (control)	37
		7-PPD (control)	66
2	212
		4	334
5	383
		7	475
9	470
		11	620
13	584
		14	535

As shown by the above data, the compounds of the present invention exhibit surprisingly superior antioxidant performance, which is in clear contrast to 6PPD and 7PPD, and demonstrate utility in fuels, lubricating oils, tires, and other applications that can benefit from highly active antioxidant compounds.

To demonstrate antiozonant efficacy, liquid nitrile rubbers of selected examples containing compounds of the present invention were subjected to thin film ozonolysis using modified infrared spectroscopy techniques. Liquid nitrile rubber was chosen as the substrate for the ozonolysis study because the nitrile group was 2237cm^-1Has an undisturbed infrared absorption which serves as a convenient internal reference for monitoring the extent of the ozonolysis reaction. The extent of the reaction was determined by measuring at 1725cm^-1The peak of carbonyl absorption at 2237cm^-1The increase in the ratio of the reference peak at (a) is followed.

To prepare the samples for this analysis, liquid nitrile rubber (1312 LV, Zeon Chemicals l.p., Louisville, KY) was dissolved in THF to make a 10% solution. For the samples in table 2 below, the antidegradants formed in example 2 and example 11 were each added to different amounts of liquid nitrile rubber solution so that the samples each contained 1 wt% concentration of the antidegradant based on the weight of the nitrile rubber. 600 microliters of each of the antidegradants-containing compositions was placed on a ZnSe-level attenuated total reflection crystal channel plate (HATR) and dried under a stream of nitrogen to produce a film of each of the compositions used for the test. A control sample using a commercial 6PPD antidegradant was also formed by the following procedure: (i) a composition was produced containing 6PPD of an antidegradant in a 10% solution of liquid nitrile rubber, wherein the amount of 6PPD was 1% by weight based on the weight of the nitrile rubber and (ii) a film of the control composition was formed as described above.

Each film sample was then ozonolysis in a Shell Lab Model CE5F oven (Shell Lab, Cornelius, OR.) polystyrene chamber maintained in thermal equilibrium at 40 ℃ with Ozone generated using an A2Z Ozone Inc. (Louisville, KY) Model MP-1000 Ozone generator. The ozonolysis reaction was allowed to proceed for 100 minutes at an ozone concentration of about 5 ppm. The IR spectra were recorded using a Perkin-Elmer Spectrum-2 spectrophotometer. The extent of ozonolysis reactions relative to 6PPD was determined to be 1725cm of test material^-1/2237 cm^-1The absorbance ratio was divided by 1725cm of 6PPD^-1/2237 cm^-1Ratio of absorbance ratios.

TABLE 2

	Compound (I)	Relative degree of ozonolysis
			Control	6PPD	1.00
1	Inventive example 2	0.43
			2	Inventive example 11	0.37

As shown by the above data, the antidegradants of the present invention reduced the relative degree of ozonolysis after 100 minutes by about 60% compared to 6 PPD. It is thus shown that the compounds of the present invention exhibit surprisingly superior antiozonant performance over current commercial antidegradants and use in applications that can benefit from highly active antiozonant compounds.

As noted above, improving the fatigue resistance of a rubber compound can significantly improve the in-service performance of the rubber compound (e.g., a tire rubber compound). Thus, the efficacy of the compounds of the present invention as anti-fatigue agents when used to make vulcanized articles formed from the vulcanizable elastomeric formulations of the present invention is determined according to the methods described below.

As a preliminary step in generating test samples, an antidegradant master batch of the composition listed in table 3 below was prepared, two of which contained the compound of the present invention as an antidegradant (particularly the compounds of example 2 and example 11 above), one control contained a conventional 6PPD antidegradant, and 4,4',4 ″ -tris (1, 3-dimethylbutylamino) triphenylamine (compound IV-a described in U.S. patent No. 8,833,417) as a second control for the antidegradant, a banbury-type mixer equipped with Kobelco inc. 1.6L with a 4-winged H-type rotor (rotor speed set at 25 rpm) was used to prepare the master batch, a Delta therm Delta T system Model AB431S temperature controller was used to control the mixer temperature to 80 ℃. the weight of the materials in the proportions given in table 3 was determined to fill 74% of the mixing chamber volume, and the rubber of carbon black, ZnO, stearic acid, antidegradant and the antidegradant was added to the mixer with a plunger 1/3 as a ram (ram) set to be in the closed position to adjust the plunger (ram) to about 30 seconds after the last mixing step was closed and the rubber was added to adjust the plunger (ram) to the mixing time after the last mixing step was closed and the mixing was started, the rubber was added to adjust the rubber to about 170 sec, and the mixing time after the plunger (ram) was added to adjust the mixing time of the mixing step was added to adjust the mixing time of the mixing to about 170 ℃ and was added to adjust the mixing time after the mixing step of the plunger) was added to adjust the mixing to about 170.5.

This "remill" step was performed in the same 1.6L mixer with the mixer control set at 80 ℃ and the rotor speed set at 65 rpm.

TABLE 3

	Example 2	Example 11	6 PPD	US 8833417 Compound (IV-a)
					Components	phr	phr	phr	phr
Natural rubber TSR-10	100	100	100	100
					N-330 carbon Black	50	50	50	50
Zinc oxide	4.0	4.0	4.0	4.0
					Stearic acid	2.5	2.5	2.5	2.5
Antidegradants	2.0	2.0	2.0	2.0
					Total of	158.5	158.5	158.5	158.5

To form test samples of the vulcanizable elastomer formulations of the invention (as well as control vulcanizable elastomer formulations), conventional vulcanizing agents (polymeric sulfur) and conventional vulcanization accelerators, N' -dicyclohexyl-2-benzothiazole sulfonamide (DCBS), were blended into each of the preformed antidegradant-containing rubber masterbatches listed in table 3 at the concentrations listed in table 4 below.

TABLE 4

	Example 2	Example 11	6-PPD	Compound No. 8,833,417 (IV-a)
					TABLE 1 Master batch	156.5	156.5	156.5	156.5
DCBS	1	1	1	1
					Polymeric sulfur	4.0	4.0	4.0	4.0
Total of	161.5	161.5	161.5	161.5

The same 1.6L laboratory mixer was used for mixing, the temperature controller was set to 80 ℃ and the rotor speed was set to 35rpm the composition was loaded into the mixer and the ram was set to off after which the batch was mixed for an additional 3 minutes after the ram was closed the total time required for the final mixing step was about three minutes forty five seconds the temperature of the vulcanizable elastomer formulation measured immediately after discharge was ~ 95 ℃.

To form samples of the vulcanized elastomer articles used for the tests, the vulcanizable elastomer formulations were subsequently sheeted on a two-roll mill to a thickness of 2 to 3 millimeters. The sheets were cut, pressed and vulcanized in a mold at 140 ℃ for 60 minutes according to ASTM D4482-11, to form 6 test specimens from each formulation. The vulcanized article was then aged for 25 days at 77 ℃ and 40% relative humidity. After aging, the samples were tested at 100% strain according to ASTM D4482-11. The relative post-aging fatigue properties as a ratio of the average of 6 inventive samples to the average of 6 control samples containing 6-PPD material are reported in table 5 below.

TABLE 5

Item numbering	Example 2	Example 11	6-PPD	Compound No. 8,833,417 (IV-a)
					Fatigue after relative aging	1.85	2.05	1.00	0.59

As shown by the above data, articles formed from the vulcanizable elastomer formulations of the present invention exhibit surprisingly superior resistance to fatigue and crack growth, which is significantly superior to articles formed using conventional 6PPD antidegradants. Thus, the compounds of the present invention impart a highly desirable level of fatigue resistance and are therefore effective anti-fatigue agents.

In another aspect briefly mentioned above, the present invention relates to a composition comprising at least one compound of the invention as described above. The specific amount of the compound of the present invention included in the composition may vary widely depending on the intended use application of the composition. One of ordinary skill in the art will appreciate that the compositions of the present invention may comprise one or more compounds of the present invention such that the concentration of each individual compound necessary to achieve the desired efficacy of the antidegradant is lower. In addition, other known antidegradant additives may be included in the composition so that reduced amounts of the compounds of the invention may be required to achieve the overall desired antidegradant efficacy.

In one embodiment, exemplified in detail hereinabove, the compositions of the present invention are vulcanizable elastomeric formulations. The vulcanizable elastomer formulation of the present invention comprises at least one elastomer and the compound of the present invention. Preferably, the compounds of the present invention are present in the vulcanizable elastomer formulation in an amount of from 0.1 to 20.0 parts, preferably from 0.1 to 5.0 parts, per 100 parts of elastomer.

The elastomer in the vulcanizable elastomer formulation may be any vulcanizable unsaturated hydrocarbon elastomer known to those skilled in the art. These elastomers may include, but are not limited to, natural rubber or any synthetic rubber, for example diene-containing elastomers such as those made from butadiene; isoprene; or a polymer of styrene and butadiene, or styrene and isoprene, or a combination of styrene, butadiene and isoprene; or polymers formed from ethylene, propylene and diene monomers such as ethylene norbornadiene or 1, 5-hexadiene. The vulcanizable elastomer formulation may also optionally include other additives conventionally used in rubber processing, such as processing/flow aids, extenders, plasticizers, resins, adhesion promoters, binders, buffers, fillers, pigments, activators, prevulcanization inhibitors, acid scorch retarders, accelerators, fatty acids, zinc oxide, or other compounding ingredients or additives to further enhance the properties and/or improve the performance of the vulcanizable elastomer formulation or the vulcanizable elastomeric articles formed therefrom. Suitable accelerators may include, but are not limited to, guanidines, thiazoles, sulfenamides, sulfimides, dithiocarbamates, xanthates, thiurams, and combinations or mixtures thereof.

The vulcanizable elastomeric formulations of the present invention are useful in the manufacture of vulcanized elastomeric articles such as rubber belts and hoses, windshield wiper blades, vehicle tires and components thereof such as treads, shoulders, sidewalls, and innerliners. Thus, in another aspect, the present invention relates to a vulcanized elastomeric article having at least one component formed from the vulcanizable elastomeric formulation of the present invention. In a particular embodiment, the vulcanized elastomeric article is a vehicle tire and the tire component is a sidewall.

Although the above aspects of the invention have been described with a focus primarily on the use in the field of compositions for the manufacture of vulcanized elastomeric articles, it will be appreciated that the compounds of the invention may also be used in compositions for other uses where antioxidant and/or antiozonant efficacy is desired. In accordance with the foregoing and as noted above, the present invention relates in a general aspect to compositions comprising a compound of the invention. In one embodiment, the composition is an antidegradant composition having the use and efficacy of inhibiting degradation of the composition, formulation or article to which it is added or applied. Thus, the antidegradant composition of the invention comprises a compound of the invention and optionally a carrier for the compound. Suitable carriers are substantially inert with respect to the compound and include waxes, oils, or solids, such as carbon black or silica.

In a separate embodiment, the composition of the invention has a separate primary use or function (e.g., a coating, lubricant, oil, fuel additive, or fuel composition) and comprises a functional ingredient and a compound of the invention as a component. The functional ingredient is typically a degradable material such as a hydrocarbon, but may also comprise other degradable materials. Thus, the present embodiments encompass, for example, lubricant compositions comprising a lubricant as a functional ingredient in combination with a compound of the present invention. The present embodiments further encompass combustible fuel compositions comprising a combustible fuel as a functional ingredient in combination with the compounds of the present invention. The present embodiments further encompass fuel additive compositions comprising a fuel additive as a functional ingredient in combination with the compounds of the present invention.

One skilled in the art will recognize that the measurements described herein are standard measurements, which may be obtained by a variety of different test methods. The described test method represents only one available method of obtaining the various required measurements.

The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.

Claims

1. A method of making an antidegradant compound, the method comprising:

reacting p-phenylenediamine with a diol to thereby obtain a mixture comprising an antidegradant compound;

wherein the p-phenylenediamine corresponds to formula IV:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen;

the diol corresponds to formula II:

wherein each R is independently selected from (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive), (ii) a substituted or unsubstituted aryl group, and (iii) a substituted and unsubstituted alkaryl group; and

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen,

the antidegradant compound is according to formula I:

wherein each R is independently selected from (i) a substituted or unsubstituted alkyl group having C =0 to 12 (inclusive), (ii) a substituted or unsubstituted aryl group, and (iii) a substituted and unsubstituted alkaryl group;

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; and is

Wherein R is¹And R³Optionally bridged by polymethylene groups to form cycloalkyl groups;

wherein when C =0 in R, R¹And R³The same; and is

Wherein when C = 1 in R, R¹And R³Each is hydrogen.

2. The process of claim 1, wherein the step of reacting the p-phenylenediamine with the diol is conducted in the presence of a metal catalyst.

3. The method of claim 2, wherein the metal catalyst comprises one or more of homogeneous and heterogeneous metal catalysts.

4. The method of claim 2, wherein the metal catalyst comprises a catalyst based on ruthenium, iridium, platinum, palladium, tin, iron, Al₂O₃And TiO₂Ligand function of one or more ofA homogeneous catalyst or a solid supported heterogeneous catalyst.

5. The method of claim 1, wherein the para-phenylenediamine comprises 4-amino-para-phenylenediamine.

6. The method of claim 1, wherein the diol comprises one or more of ethylene glycol, propylene glycol, butylene glycol, or 1, 8-octanediol.

7. The method of claim 1, wherein the antidegradant compound comprises N, N' - (octane-1, 8-diyl) bis (N-phenyl-benzene-1, 4-diamine).

8. The method of claim 1, wherein the antidegradant compound comprises N, N' - (ethane-1, 2-diyl) bis (N-phenyl-benzene-1, 4-diamine).

9. The method of claim 1, wherein the antidegradant compound comprises N, N' - (1, 4-phenylenebis (ethane-1, 1-diyl)) bis (N-phenyl-1, 4-diamine).

10. The method of claim 1, wherein the antidegradant compound comprises N, N' - (1, 3-phenylenebis (ethane-1, 1-diyl)) bis (N-phenyl-1, 4-diamine).

11. The method of claim 1, wherein the antidegradant compound comprises (N, N ', N ') -N, N ' - (1, 4-phenylenebis (ethan-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine).

12. The method of claim 1, wherein the antidegradant compound comprises (N, N ', N ') -N, N ' - (1, 3-phenylenebis (ethan-1-yl-1-ylidene)) bis (N-phenylphenyl-1, 4-diamine).