WO2022048565A1 - Preparation method for asymmetric diaryl substituted p-phenylenediamine compound - Google Patents

Abstract

The present invention provides a preparation method for an asymmetric diaryl substituted p-phenylenediamine compound. The compound has the structure as shown in the following formula A. The method comprises: (1) reacting p-dihydroxybenzene with a compound of formula B in the presence of a supported F_eCl₃ catalyst, to obtain a compound of formula C; and (2) reacting the compound of formula C with a compound of formula D in the presence of an anhydrous F_eCl₃ catalyst, to obtain a compound of formula A. In formulas A-D, the groups are defined as described in the text. The method can efficiently and conveniently prepare the asymmetric diaryl substituted p-phenylenediamine compound.

Description

Preparation method of asymmetric diaryl substituted p-phenylenediamine compounds technical field

The invention belongs to the field of rubber antioxidants, in particular to asymmetric diaryl-substituted p-phenylenediamine compounds and a preparation method thereof.

Background technique

Existing literature studies have shown that diaryl-substituted p-phenylenediamine has a long-term anti-aging effect. Compared with the widely used antioxidant 4020, diaryl-p-phenylenediamine is less volatile, resistant to extraction, and has a more durable protective effect. For example, antioxidant H and antioxidant 3100 are typical after-effect long-acting antioxidants, which can supplement the shortcomings of 4010 and 4020 type antioxidants that have good anti-aging effects in the early stage and slightly worse in the later stage.

However, the anti-aging agent H is N,N'-diphenyl-p-phenylenediamine with a symmetrical structure, which has strong crystallinity and poor compatibility with rubber. , causing discoloration and pollution of the tread, and quickly losing the protection against rubber aging. Blooming is a phenomenon in which the liquid or solid compounding agent inside the rubber migrates to the surface and precipitates. Anti-aging agent 3100 is a mixture, of which about 45% is diaryl-p-phenylenediamine with symmetrical structure (23% N,N'-diphenyl-p-phenylenediamine and 22% N,N'-bis(methyl)p-phenylenediamine phenylenediamine), the other 45% is N-phenyl-N'-tolyl-p-phenylenediamine with asymmetric structure, so antioxidant 3100 is also prone to blooming phenomenon, and the dosage is generally not more than 1.5 parts.

U.S. Patent Document US3432460 introduces the synthetic method of diaryl-p-phenylenediamine antiaging agent, the preparation of antiaging agent H takes hydroquinone and aniline as reaction raw materials, takes Lewis acid such as anhydrous ferric chloride as catalyst, high temperature micro The positive pressure toluene is refluxed with water, and the amount of water brought out is used as a sign to measure the end of the reaction. After the reaction is completed, the temperature is lowered and a saturated aqueous sodium carbonate solution is added to quench the reaction. Inorganic solidification after cooling. If a mixture of aniline and o-toluidine is reacted with hydroquinone, a three-component mixture, namely antioxidant 3100, is obtained. According to the reaction principle, the one-component asymmetric diaryl-p-phenylenediamine cannot be obtained according to this process.

European patent document EP0588060A2 adopts the method of first synthesizing N-alkyl-substituted phenyl-p-phenylenediamine, and then condensing and dehydrogenating it with different alkyl-substituted cyclohexanone to generate asymmetric diaryl-substituted p-phenylenediamine. In the preparation method, the alkyl-substituted cyclohexanone is difficult to synthesize, the cost is relatively high, and the hydrogen acceptor needs to be consumed, and a large amount of by-products are easily generated.

The US patent document US4804783A adopts the first synthesis of N-alkyl-substituted phenyl-p-phenylenediamine, and then condensation with different alkyl-substituted phenols to prepare the target product. In the preparation method, cyclohexanone is required as a hydrogen transfer reagent, the reaction conditions are harsh, and it is not easy to carry out, especially the alkyl-substituted phenol is difficult to react, and the product can hardly be obtained.

Therefore, there is a need in the art for a preparation method of an asymmetric diaryl-substituted p-phenylenediamine compound with low cost, few side reactions, less severe reaction conditions and high yield.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a new method for preparing asymmetric diaryl-substituted p-phenylenediamine compounds. Asymmetric diaryl-substituted p-phenylenediamine compounds are usually used as anti-aging agents for rubber products, especially rubber tires, which can prevent rubber products or rubber tires from being damaged by light, heat, oxygen, fatigue, etc. during long-term use. Degradation. Compared with the existing method for preparing asymmetric diaryl-substituted p-phenylenediamine compounds, the method of the invention has the advantages of lower cost, less side reactions, less severe reaction conditions and higher yield.

Specifically, the present invention provides a method for preparing an asymmetric diaryl-substituted p-phenylenediamine compound, wherein the asymmetric diaryl-substituted p-phenylenediamine compound has the structure shown in the following formula A:

In formula A, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5, each R _b is independently selected from hydrogen and C1-C6 alkyl, and n is selected from 0-5 Integer; compounds of formula A do not include compounds in which (R _a ) _m substituted phenyl and (R _b ) _n substituted phenyl are the same;

The method includes:

(1) in the presence of supported FeCl catalyst, hydroquinone and _formula B compound are reacted to obtain formula C compound:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula C and the compound of formula D are reacted to obtain the compound of formula A:

Wherein, in the compound of formula B, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5; in the compound of formula D, each R _b is independently selected from hydrogen and C1-C6 alkyl, n is an integer selected from 0 to 5; the compound of formula B is not the same as the compound of formula D.

In one or more embodiments, the supported FeCl ₃ catalyst is a catalyst obtained by supporting FeCl ₃ on a carrier.

In one or more embodiments, the reaction of step (1) is carried out in a non-polar solvent.

In one or more embodiments, the reaction temperature of step (1) is 200-240°C.

In one or more embodiments, the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst added in step (1) to hydroquinone added in step (1) is (0.08-0.4):1.

In one or more embodiments, the molar ratio of the compound of formula B added in step (1) to the hydroquinone added in step (1) is (0.8-1.2):1.

In one or more embodiments, the reaction of step (1) is carried out in an inert gas atmosphere.

In one or more embodiments, the reaction of step (2) is carried out in a non-polar solvent.

In one or more embodiments, the reaction temperature of step (2) is 230-270°C.

In one or more embodiments, the molar ratio of the anhydrous FeCl ₃ added in step (2) to the hydroquinone added in step (1) is (0.1-0.5):1.

In one or more embodiments, the molar ratio of the compound of formula D added in step (2) to the hydroquinone added in step (1) is (1.0-1.8):1.

In one or more embodiments, the reaction of step (2) is carried out in an inert gas atmosphere.

In one or more embodiments, the carrier of the supported FeCl ₃ catalyst is selected from the group consisting of hydrogen-type molecular sieves, activated silica and activated alumina.

In one or more embodiments, in the supported FeCl ₃ catalyst, the mass ratio of FeCl ₃ to the carrier is 1:(5-10).

In one or more embodiments, the reaction of step (1) is performed in toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or in trimethylcyclohexane.

In one or more embodiments, the reaction temperature of step (1) is 220-230°C.

In one or more embodiments, the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst added in step (1) to hydroquinone added in step (1) is (0.1-0.25):1.

In one or more embodiments, the molar ratio of the compound of formula B added in step (1) to the hydroquinone added in step (1) is (0.9-1.1):1.

In one or more embodiments, the reaction of step (1) is carried out in a nitrogen atmosphere.

In one or more embodiments, the reaction of step (2) is performed in toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or in trimethylcyclohexane.

In one or more embodiments, the reaction temperature of step (2) is 240-260°C.

In one or more embodiments, the molar ratio of the anhydrous FeCl ₃ added in step (2) to the hydroquinone added in step (1) is (0.2-0.3):1.

In one or more embodiments, the molar ratio of the compound of formula D added in step (2) to the hydroquinone added in step (1) is (1.2-1.5):1.

In one or more embodiments, the reaction of step (2) is carried out in a nitrogen atmosphere.

In one or more embodiments, the carrier _of the supported FeCl catalyst is selected from hydrogen molecular sieves, activated silica and activated alumina; in the supported FeCl catalyst, the mass ratio _of FeCl to the carrier is ₁ : (5-10); the reaction of step (1) is in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylbenzene In the reaction system of step (1), the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst to hydroquinone is (0.1 -0.25): 1, the molar ratio of the compound of formula B to hydroquinone is (0.9-1.1): 1; the reaction of step (1) is carried out in a nitrogen atmosphere; the reaction of step (2) is carried out in toluene, xylene, Trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane; the reaction temperature of step (2) is 240～260℃ ; The mol ratio of the anhydrous FeCl added in the step ( ₂ ) and the hydroquinone added in the step (1) is (0.2-0.3): 1; The formula D compound added in the step (2) and the step (1) The molar ratio of hydroquinone added in ) is (1.2-1.5):1; and the reaction of step (2) is carried out in a nitrogen atmosphere.

The present invention also provides a method for preparing the compound of the following formula I:

In formula I, R ₁ and R ₃ are each independently hydrogen or C1-C6 alkyl; R ₂ is C1-C6 alkyl; the compound of formula I does not include R ₁ , R ₂ substituted phenyl and R ₃ substituted phenyl the same compound;

The method includes:

(1) in the presence of supported FeCl catalyst, hydroquinone and _formula II compound are reacted to obtain formula III compound:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula III and the compound of formula IV are reacted to obtain the compound of formula I:

Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different; or

The method includes:

(1) in the presence of supported FeCl catalyst, hydroquinone and _formula IV compound are reacted to obtain formula III' compound:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula III ' is reacted with the compound of formula II to obtain the compound of formula I:

Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different.

In one or more embodiments of the method for preparing the compound of formula I, the supported FeCl ₃ catalyst is a catalyst obtained by loading FeCl ₃ on a carrier.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (1) is carried out in a non-polar solvent.

In one or more embodiments of the method of preparing the compound of formula I, the reaction temperature of step (1) is 200-240°C.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of FeCl3 contained in the supported FeCl3 catalyst added in step ( ₁ ) to the hydroquinone added in step ( ₁ ) is ( 0.08-0.4):1.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the compound of formula II or compound of formula IV added in step (1) to the hydroquinone added in step (1) is (0.8-1.2 ): 1.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (1) is carried out under an inert gas atmosphere.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (2) is carried out in a non-polar solvent.

In one or more embodiments of the method of preparing the compound of formula I, the reaction temperature of step (2) is 230-270°C.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the anhydrous FeCl3 added in step ( ₂ ) to the hydroquinone added in step (1) is (0.1-0.5):1 .

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the compound of formula IV or the compound of formula II added in step (2) to the hydroquinone added in step (1) is (1.0- 1.8): 1.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (2) is carried out under an inert gas atmosphere.

In one or more embodiments of the method of preparing the compound of formula I, the support _of the supported FeCl3 catalyst is selected from the group consisting of hydrogen-type molecular sieves, activated silica, and activated alumina.

In one or more embodiments of the method for preparing the compound of formula I, in the supported FeCl ₃ catalyst, the mass ratio of FeCl ₃ to the support is 1:(5-10).

In one or more embodiments of the process for preparing the compound of formula I, the reaction of step (1) is performed in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylbenzene cyclohexane and/or trimethylcyclohexane.

In one or more embodiments of the method of preparing the compound of formula I, the reaction temperature of step (1) is 220-230°C.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of FeCl3 contained in the supported FeCl3 catalyst added in step ( ₁ ) to the hydroquinone added in step ( ₁ ) is ( 0.1-0.25):1.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the compound of formula II or compound of formula IV added in step (1) to the hydroquinone added in step (1) is (0.9-1.1 ): 1.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (1) is carried out under a nitrogen atmosphere.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (2) is performed in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylbenzene cyclohexane and/or trimethylcyclohexane.

In one or more embodiments of the method of preparing the compound of formula I, the reaction temperature of step (2) is 240-260°C.

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the anhydrous FeCl3 added in step ( ₂ ) to the hydroquinone added in step (1) is (0.2-0.3):1 .

In one or more embodiments of the method for preparing the compound of formula I, the molar ratio of the compound of formula IV or the compound of formula II added in step (2) to the hydroquinone added in step (1) is (1.2-1.5 ): 1.

In one or more embodiments of the method of preparing the compound of formula I, the reaction of step (2) is carried out under a nitrogen atmosphere.

In one or more embodiments of the method for preparing the compound of formula I, the carrier of the supported FeCl3 catalyst is selected from hydrogen molecular sieves, activated silica and activated alumina; in the supported FeCl3 catalyst, the FeCl3 and the carrier are The mass ratio is 1: (5-10); the reaction of step (1) is in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and / or in trimethylcyclohexane; the reaction temperature of step (1) is 220-230 ° C; in the reaction system of step (1), the molar ratio of FeCl3 contained in the supported FeCl3 catalyst to hydroquinone is (0.1-0.25): 1, the molar ratio of the compound of formula II or the compound of formula IV to hydroquinone is (0.9-1.1): 1; the reaction of step (1) is carried out in a nitrogen atmosphere; the reaction of step (2) In toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane; the reaction of step (2) The temperature is 240-260° C.; the molar ratio of the anhydrous FeCl added in the step (2) to the hydroquinone added in the step (1) is (0.2-0.3): 1; the formula IV added in the step (2) The molar ratio of the compound or the compound of formula II to the hydroquinone added in step (1) is (1.2-1.5):1; and the reaction of step (2) is carried out in a nitrogen atmosphere.

In one or more embodiments of the method for preparing the compound of formula I, in formula I, R ₁ is hydrogen, and R ₂ and R ₃ are each independently C1-C6 alkyl; or R ₃ is hydrogen, and R ₁ and R ₂ Each independently is a C1-C6 alkyl group; or R ₁ , R ₂ and R ₃ are each independently a C1-C6 alkyl group.

In one or more embodiments of the method of preparing a compound of formula I, the C1-C6 alkyl group is selected from the group consisting of methyl, ethyl, propyl and butyl.

In one or more embodiments of the method of preparing a compound of formula I, the C1-C6 alkyl group is selected from methyl and isobutyl.

In one or more embodiments of the method of making a compound of formula I, the compound of formula I is selected from:

The present invention also provides a supported FeCl ₃ catalyst, the carrier of the supported FeCl ₃ catalyst is selected from hydrogen type molecular sieves, activated silica and activated alumina, and in the supported FeCl ₃ catalyst, the FeCl ₃ and the carrier are The mass ratio is 1:(5-10).

In one or more embodiments, the carrier of the supported FeCl ₃ catalyst is prepared by heating reaction between anhydrous FeCl ₃ and the carrier in an alcohol solvent.

detailed description

In order for those skilled in the art to understand the features and effects of the present invention, general descriptions and definitions of terms and expressions mentioned in the specification and claims are hereunder. Unless otherwise specified, all technical and scientific terms used in the text have the ordinary meaning understood by those skilled in the art to the present invention, and in case of conflict, the definitions in this specification shall prevail.

The theory or mechanism described and disclosed herein, whether true or false, should not in any way limit the scope of the invention, ie, the present invention may be practiced without being limited by any particular theory or mechanism.

Herein, all features such as amounts, amounts, and concentrations defined in terms of numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible sub-ranges and individual numerical values (including integers and fractions) within the ranges.

Herein, unless otherwise specified, the ratio refers to the mass ratio, and the percentage refers to the mass percentage.

Herein, for the sake of brevity of description, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, each technical feature in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope of the description.

As used herein, the terms "comprising", "including" or "comprising" mean that the various ingredients are applicable together in the mixture or composition of the present invention. Thus, the terms "consisting essentially of" and "consisting of" are encompassed by the terms "comprising", "including" or "comprising".

Herein, alkyl refers to a linear or branched monovalent saturated hydrocarbon group, usually containing 1-16 carbon atoms (C1-C16 alkyl), for example, containing 3-16 carbon atoms (C3-C16 alkyl). Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 1,4-dimethylpentyl, and t-octyl.

Herein, the asymmetric diaryl-substituted p-phenylenediamine compound refers to a compound that can be regarded as a compound obtained by substituting two different aryl groups for hydrogen atoms on two amino groups of p-phenylenediamine, respectively. For example, an asymmetric diaryl-substituted p-phenylenediamine compound can have the structure shown in the following formula A:

In formula A, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5, each R _b is independently selected from hydrogen and C1-C6 alkyl, and n is selected from 0-5 Integer; and (R _a ) _m substituted phenyl and (R _b ) _n substituted phenyl are not the same.

Herein, the same substituted phenyl group means that the number of substituents on the phenyl group, the position of each substituent and the substituent groups on the corresponding positions are all the same.

In the present invention, C1-C6 alkyl groups as R _a or R _b include but are not limited to methyl, ethyl, propyl and butyl, wherein propyl includes n-propyl and isopropyl, and butyl includes n-butyl , isobutyl, and tert-butyl, ie, each of _Ra and _Rb can each be independently selected from hydrogen, methyl, ethyl, propyl, and butyl. In some embodiments, the C1-C6 alkyl group as _Ra or _Rb is methyl or tert-butyl, ie, each of _Ra and _Rb is independently selected from hydrogen, methyl, and tert-butyl.

In formula A, m is preferably an integer selected from 0-3, more preferably an integer selected from 0-2. In Formula A, n is preferably an integer selected from 0-3, and more preferably an integer selected from 0-2.

The inventors of the present invention found that the asymmetric diaryl-substituted p-phenylenediamine compound (referred to as compound I or compound of formula I) as shown in the following formula I can not only provide long-term effects similar to antioxidant H or antioxidant 3100 Anti-aging properties and can improve bloomability:

Wherein, R ₁ and R ₃ are each independently hydrogen or C1-C6 alkyl; R ₂ is C1-C6 alkyl; and the phenyl substituted by R ₁ and R ₂ is different from the phenyl substituted by R ₃ .

In the present invention, C1-C6 alkyl as R ₁ , R ₂ or R ₃ includes but is not limited to methyl, ethyl, propyl and butyl, wherein propyl includes n-propyl and isopropyl, and butyl Included are n-butyl, isobutyl and tert _- butyl, ie each R1, R2 and _R3 can each be independently selected from _hydrogen , methyl, ethyl, propyl and butyl. In some embodiments, the C1-C6 alkyl as R ₁ , R ₂ or R ₃ is methyl or tert-butyl, ie each R ₁ , R ₂ and R ₃ are each independently selected from hydrogen, methyl and tert-butyl base.

In some embodiments, in Formula I, when R ₁ is hydrogen, R ₂ and R ₃ represent different groups, or R ₂ and R ₃ represent the same groups but on respective substituted phenyl groups location is not the same.

In some embodiments, in Formula I, when R ₁ is hydrogen, R ₂ and R ₃ represent different groups.

In some embodiments, in Formula I, R ₁ and R ₃ are not both hydrogen.

In some embodiments, in formula I, R ₁ is hydrogen, R ₂ and R ₃ are each independently a C1-C6 alkyl group, and R ₂ and R ₃ are different.

In some embodiments, in formula I, R ₃ is hydrogen, and R ₁ and R ₂ are each independently C1-C6 alkyl.

In some embodiments, in Formula I, R ₁ , R ₂ , and R ₃ are each independently C1-C6 alkyl.

In some embodiments, Compound 1 has the structure shown in any one of Formulas 1-1 to 1-6 below:

The present invention provides a method for an asymmetric diaryl-substituted p-phenylenediamine compound (referred to as a compound of formula A) having the structure shown in the following formula A:

In formula A, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5, each R _b is independently selected from hydrogen and C1-C6 alkyl, and n is selected from 0-5 Integer; compounds of formula A do not include compounds in which (R _a ) _m substituted phenyl and (R _b ) _n substituted phenyl are the same;

The method includes the following steps:

(1) in the presence of a supported FeCl ₃ catalyst (FeCl ₃ /support), hydroquinone and the compound of formula B are reacted to obtain the compound of formula C:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula C and the compound of formula D are reacted to obtain the compound of formula A:

Wherein, in the compound of formula B, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5; in the compound of formula D, each R _b is independently selected from hydrogen and C1-C6 alkyl, n is an integer selected from 0 to 5; the compound of formula B is not the same as the compound of formula D.

In the preparation method of the compound of formula A of the present invention, the preferred R _a , the preferred m in the compound B, the preferred R _b , and the preferred n in the compound D can be as described in any of the embodiments herein.

The methods for the preparation of compounds of formula A are also applicable to the preparation of compounds of formula I described in any of the embodiments herein.

The method of preparing the compound of formula I may comprise the following steps:

(1) in the presence of supported FeCl catalyst, hydroquinone and _formula II compound are reacted to obtain formula III compound:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula III and the compound of formula IV are reacted to obtain the compound of formula I:

Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different.

The method of preparing the compound of formula I may also comprise the steps of:

(1) in the presence of supported FeCl catalyst, hydroquinone and _formula IV compound are reacted to obtain formula III' compound:

( ₂ ) in the presence of anhydrous FeCl , the compound of formula III ' is reacted with the compound of formula II to obtain the compound of formula I:

Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different.

In the preparation method of the compound of formula I of the present invention, the preferred R ₁ and R ₂ in compound II and the preferred R ₃ in compound IV can be as described in any of the embodiments herein.

The present invention adopts a two-step method to prepare asymmetric diaryl-substituted p-phenylenediamine. In the first step, supported FeCl ₃ is used as a catalyst. Since ferric iron is stably bonded to the surface of the carrier, its catalytic activity is weaker than that of free FeCl ₃ . Therefore, the target product arylaminophenol is restricted from further reacting with aromatic amines to generate symmetrical diaryl-p-phenylenediamine; in addition, the pore structure of the carrier further limits the generation of diaryl-p-phenylenediamine from space.

The reaction of step (1) is carried out in a non-polar solvent; for example, the non-polar solvent can be toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane Hexane, trimethylcyclohexane, etc., preferably toluene or xylene. The reaction of step (1) is carried out under the conditions of raising the temperature to reflux for azeotropy and dehydration. The reaction temperature of the step (1) is preferably 200 to 240°C, more preferably 220 to 230°C. The way of dehydration can be conventional in the art, for example, dehydration can be done by using a water separator. The reaction of step (1) is preferably carried out in an inert gas (eg nitrogen) atmosphere.

It is found in the present invention that in the first step reaction of preparing asymmetric diaryl-substituted p-phenylenediamine, supported FeCl ₃ is used as a catalyst to prepare arylaminophenol, and the further reaction of arylaminophenol with arylamine is restricted to generate Symmetrical diaryl-p-phenylenediamine. In the present invention, the supported FeCl ₃ catalyst refers to a catalyst obtained by supporting FeCl ₃ on a carrier. In the supported FeCl ₃ catalyst, ferric iron is stably bonded to the carrier, and the mass ratio of FeCl ₃ to the carrier is preferably 1:(5-10). The carrier of the supported FeCl ₃ catalyst can be hydrogen molecular sieve, activated silica or activated alumina. Herein, activated alumina and activated silica refer to solid silica and solid alumina that contain hydroxyl groups on the inner and outer surfaces and are porous. The hydrogen type molecular sieve can be, for example, GENERAL-REAGENT, 4A of Shanghai Titan Chemical Co., Ltd. The active silica can be, for example, GENERAL-REAGENT, G72651A from Shanghai Titan Chemical Co., Ltd. The activated alumina can be, for example, GENERAL-REAGENT, G21116K from Shanghai Titan Chemical Co., Ltd.

The supported FeCl ₃ catalyst used in the present invention can be prepared by heating reaction between anhydrous FeCl ₃ and a carrier in a solvent. The solvent used in preparing the supported FeCl ₃ catalyst can be an alcohol solvent, preferably a C1-C3 monohydric alcohol, such as methanol. The mass ratio of FeCl ₃ and solvent in the reaction system is usually 1:5 to 1:20, for example, 1:9 to 1:19. The mass ratio of FeCl ₃ and carrier in the reaction system is usually 1:(5-10). The reaction is usually carried out under stirring and refluxing conditions. The reaction time is usually 5 to 10 hours, preferably 7 to 8 hours. After the reaction is completed, the solvent is removed to obtain a supported FeCl ₃ catalyst. The method of removing the solvent can be, for example, distilling off the solvent under heating and vacuum conditions.

_In some embodiments, the supported FeCl catalyst is prepared by the following method:

Weigh a certain amount of anhydrous FeCl ₃ , prepare a solution with a concentration of 5-10 wt % with methanol, add it into a four-necked flask equipped with mechanical stirring, a thermometer and a reflux condenser, add a certain amount of dried carrier, FeCl ₃ and FeCl 3 The mass ratio of the carrier is 1:(5～10), start the mechanical stirring, gradually heat up to methanol reflux, keep refluxing for 7～8h, then steam out methanol, heat up to 140～150℃ and vacuum to about 10kPa absolute pressure, keep 5~6h, after cooling, quickly pour it into a clean and dry reagent bottle, and store it in a desiccator.

In step (1), the molar ratio of FeCl ₃ contained in the added supported FeCl ₃ catalyst to the added hydroquinone is preferably (0.08-0.4):1, more preferably (0.1-0.25):1. In step (1), the molar ratio of the added compound of formula B (for example, the compound of formula II or the compound of formula IV) to the added hydroquinone is preferably (0.8-1.2): 1, more preferably (0.9-1.1): 1.

Whether the reaction in step (1) is completed can be determined by detecting whether water is generated, and the reaction is completed when no more water is generated. After the reaction of step (1) is completed, the catalyst is filtered out while hot, and the solvent and unreacted compound of formula B (for example, compound of formula II or compound of formula IV) are distilled off under reduced pressure to obtain compound of formula C (for example, compound of formula III or compound of formula III) ' compound); filtration and vacuum distillation are preferably carried out at the reaction temperature of step (1); the vacuum degree of vacuum distillation is preferably lower than 5 mmHg.

The reaction of step (2) is carried out in a non-polar solvent; for example, the non-polar solvent can be toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane Hexane, trimethylcyclohexane, etc., preferably toluene or xylene. The reaction of step (2) is carried out under the conditions of raising the temperature to reflux for azeotropy and dehydration. The reaction temperature of step (2) is preferably 230-270°C, preferably 240-260°C. The way of dehydration can be conventional in the art, for example, dehydration can be done by using a water separator. The reaction of step (2) is preferably carried out in an inert gas (eg nitrogen) atmosphere.

The molar ratio of the anhydrous FeCl ₃ added in step (2) to the hydroquinone added in step (1) is preferably (0.1-0.5):1, more preferably (0.2-0.3):1. The molar ratio of the compound of formula D (for example, the compound of formula IV or the compound of formula II) added in step (2) to the hydroquinone added in step (1) is preferably (1.0-1.8): 1, more preferably (1.2 -1.5): 1.

Whether the reaction in step (2) is completed can be determined by detecting whether water is generated, and the reaction is completed when no more water is generated. After the reaction of step (2) is completed, the temperature is lowered to about 80～100° C., an appropriate amount of lye is added to neutralize, the temperature is increased and the pressure is reduced to distill out water, solvent and unreacted compound of formula D (for example, compound of formula IV or compound of formula II), Filter while hot, and the filtrate is cooled and solidified to obtain a compound of formula A (for example, a compound of formula I); the neutralization time is preferably 0.5-1.5h; the lye can be, for example, an aqueous solution of a weakly basic salt; the weakly basic salt can be sodium carbonate, Potassium carbonate, sodium phosphate, potassium phosphate, etc.; the vacuum degree of vacuum distillation is preferably lower than 5mmHg; the temperature of vacuum distillation is preferably 250-300°C; the temperature of filtration is preferably 130-160°C.

The method of the present invention has the following advantages:

(1) the method of the present invention can prepare a single-component asymmetric diaryl-substituted p-phenylenediamine compound, and the prior art is difficult to prepare a single-component asymmetric diaryl-p-phenylenediamine;

(2) the cost is lower: it is not necessary to use the substituted cyclohexanone with higher cost as the reaction raw material;

(3) Fewer side reactions and high yield: the reaction does not need to add hydrogen acceptors, the side reactions are few, the yield can reach more than 80%, and the product purity can reach more than 85%;

(4) The reaction conditions are not harsh: the reaction can be carried out under the catalysis of heating and supported FeCl ₃ catalyst or anhydrous FeCl ₃ .

Compound I of the present invention can be used as a rubber antioxidant, providing longer lasting protection than conventional antioxidants without blooming. Accordingly, the present invention provides rubber compositions containing one or more of the compounds I of the present invention. Raw materials for rubber compositions generally include diene elastomers, reinforcing fillers, antioxidants, and cross-linking agents. The amount of diene elastomer, reinforcing filler, anti-aging agent and cross-linking agent may be the conventional amount in the art. Based on 100 parts by mass of diene elastomer, the amount of Compound I in the rubber composition may be 0.1-5 parts by mass, for example, 0.5-5 parts by mass, 1-3 parts by mass, and 1-2 parts by mass. Herein, the rubber composition includes unvulcanized rubber and vulcanized rubber. Vulcanized rubber can be obtained by vulcanizing (curing) the unvulcanized rubber.

Diene elastomers refer to elastomers whose monomers comprise a diene (eg, butadiene, isoprene). Diene elastomers suitable for use in the present invention may be various diene elastomers known in the art, including but not limited to those selected from natural rubber (NR), cis-butadiene rubber (BR), isoprene rubber, styrene-butadiene rubber ( SBR), neoprene (CR), nitrile rubber (NBR), isoprene/butadiene copolymers, isoprene/styrene copolymers and isoprene/butadiene/styrene copolymers one or more of these. In certain embodiments, in the rubber composition of the present invention, the diene elastomer is composed of natural rubber (such as SCR5) and cis-butadiene rubber (such as BR9000); the mass ratio of natural rubber and cis-butadiene rubber is not particularly limited, for example, 1:9 to 9:1, 2:8 to 8:2, 3:7 to 7:3, 4:6 to 6:4, or about 1:1.

The reinforcing filler may be one conventionally used in rubber, including but not limited to one or more selected from the group consisting of carbon black, titanium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, clay, and talc kind. The amount of the reinforcing filler may be 40-60 parts by mass per 100 parts by mass of the diene elastomer.

The crosslinking agent can be sulfur. The cross-linking agent may be used in an amount of 1-3 parts by mass per 100 parts by mass of the diene elastomer.

The amount of the antioxidant may be 0.1-5 parts by mass, 0.5-5 parts by mass, 1-3 parts by mass or 1-2 parts by mass of the antioxidant per 100 parts by mass of the diene elastomer. In the rubber composition of the present invention, the anti-aging agent may be Compound I or a combination of Compound I and a conventional anti-aging agent.

The raw materials of the rubber composition may also include other components commonly used in rubber, including but not limited to auxiliary agents and accelerators. The amount of adjuvant and accelerator can be the conventional amount in the art.

Adjuvants may include softeners used to improve processability. The softener can be a petroleum-based softener such as aromatic oil, processing oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt and petrolatum, etc., or a fatty oil-based softener such as castor oil, linseed oil, rapeseed oil, coconut Oils, waxes (such as beeswax, carnauba wax and lanolin), tall oil, linoleic acid, palmitic acid, stearic acid and lauric acid, etc. Auxiliaries can also include active agents, such as zinc oxide, which can accelerate the vulcanization speed, improve the thermal conductivity, wear resistance, tear resistance and the like of the rubber. Usually, a total of 5-20 parts by mass of adjuvants is used per 100 parts by mass of diene elastomer, for example, 2-8 parts by mass of aromatic oil, 2-8 parts by mass of zinc oxide and 1-4 parts by mass of hardener can be used fatty acid.

Accelerators are usually vulcanization accelerators, which can be sulfonamides, thiazoles, thiurams, thioureas, guanidines, dithiocarbamates, aldehyde amines, aldehyde ammonia, imidazoline and xanthogen At least one of acid-based vulcanization accelerators. For example, the accelerator may be the accelerator NS (N-tert-butyl-2-benzothiazole sulfenamide). Typically, 0.5-1.5 parts by mass of the accelerator is used per 100 parts by mass of the diene elastomer.

In addition, if necessary, plasticizers such as DMP (dimethyl phthalate), DEP (diethyl phthalate), DBP (dibutyl phthalate) can also be used in the rubber composition , DHP (diheptyl phthalate), DOP (dioctyl phthalate), DINP (diisononyl phthalate), DIDP (diisodecyl phthalate), BBP (o- butyl benzyl phthalate), DWP (dilauryl phthalate) and DCHP (dicyclohexyl phthalate) and the like. The amount of the plasticizer is the conventional amount in the art.

The unvulcanized rubber of the present invention can be prepared by a conventional rubber mixing method, for example, a two-stage mixing method is used to prepare: one-stage internal mixer mixing, mixing diene elastomer, reinforcing filler, auxiliary agent and anti-aging agent, and degumming The temperature is above 110 °C; the two-stage open mill is mixed, and the glue obtained in the first stage is mixed with the cross-linking agent and accelerator. Usually, the diene elastomer is first added to a thermomechanical mixer (such as an internal mixer), and after kneading for a certain period of time, the reinforcing filler, auxiliary agent, and anti-aging agent are added, and the kneading is continued until the mixing is uniform, and the reinforcing filler, auxiliary agent, and anti-aging agent are added. It can be added in batches, and the temperature during kneading is controlled between 110°C and 190°C, preferably between 150°C and 160°C; then, the mixture is cooled to below 100°C, crosslinking agent and accelerator are added, kneaded again, and kneaded During the period, the temperature is controlled below 110°C, such as about 70°C, to obtain unvulcanized rubber.

The unvulcanized rubber of the present invention can be vulcanized by a conventional vulcanization method to obtain a vulcanized rubber; the vulcanization temperature is usually 130 ℃-200 ℃, such as about 145 ℃; the vulcanization time depends on the vulcanization temperature, vulcanization system and vulcanization kinetics, usually 15 -60 minutes, like 30 minutes or so. The unvulcanized rubber obtained by kneading can be subjected to conventional tableting prior to vulcanization.

When the compound I and the rubber composition of the present invention are used in rubber products, especially rubber tires, they can impart longer-lasting anti-aging properties to the rubber products or rubber tires without blooming. Therefore, the present invention also provides a rubber product having the rubber composition of the present invention as its rubber component. Rubber products can be tires, rubber shoes, weather strips, sound insulation boards, shock pads, etc. In certain embodiments, the rubber article is a tire, such as a tire tread, belt, and sidewall. The belt layer of the tire, in addition to the rubber composition of the present invention, may also contain reinforcing materials conventionally used in the art.

The asymmetric diaryl-substituted p-phenylenediamine compound of the present invention can prevent the rubber product from blooming during use. The present invention also provides the use of the compound I of the present invention for improving the anti-aging properties and/or blooming properties of rubber or rubber products.

Hereinafter, the present invention will be described by way of specific examples in order to better understand the content of the present invention. It should be understood that these examples are merely illustrative and not restrictive. The raw materials and reagents used in the examples, unless otherwise specified, are conventionally purchased from the market. The experimental methods, preparation methods and detection methods used in the examples are all conventional methods unless otherwise specified. The instruments and equipment used in the examples, unless otherwise specified, are conventional instruments and equipment in the art. In the embodiment, unless otherwise specified, the percentage refers to the mass percentage.

_The supported FeCl catalyst used in the embodiment is prepared by the following method:

Weigh a certain amount of anhydrous FeCl ₃ , prepare a methanol solution of FeCl ₃ with a concentration of 8wt% with methanol, add it into a four-necked flask equipped with a mechanical stirring, a thermometer and a reflux condenser, add a certain amount of dried carrier, FeCl 3 The mass ratio of ₃ and the carrier is 1:8, start the mechanical stirring, gradually heat up to methanol reflux, keep refluxing for 8h, then evaporate the methanol, heat up to 150 ° C and evacuate to the absolute pressure of 10kPa, keep it for 6h, quickly pour it after cooling Store in clean and dry reagent bottles in a desiccator. In Example 1-11, the supported FeCl catalyst prepared by using hydrogen-type molecular sieve (Shanghai Titan Chemical Co., Ltd., GENERAL-REAGENT, 4A) as a carrier, and active silica (Shanghai Titan Chemical Co., Ltd. ₎ was used in Example 12. , GENERAL-REAGENT, _G72651A ) as the supported FeCl catalyst prepared by the carrier, in Example ₁₃ , the supported FeCl catalyst prepared by using activated alumina (Shanghai Titan Chemical Co., Ltd., GENERAL-REAGENT, G21116K) as the carrier .

Example 1: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) 96.8g (0.8mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 12.96g (0.08mol) of 2,3-dimethylaniline, 12.96g (0.08mol) of ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 200 ℃ of reaction to no water in the water separator, filter out the catalyst while hot, at this temperature, decompression distill out toluene and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 16.2g (0.1mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 230 ℃ and react until there is no water in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, then filter while hot, the filtrate is cooled and solidified into a block product 212g (yield 81.0%) ), the content measured by sampling GC analysis was 88%, and the molecular weight measured by mass spectrometry was 288.

Example 2: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 121g (1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 12.96g (0.08mol) of FeCl to the 1L stainless steel reactor equipped with condenser and water separator ₃ of the supported FeCl catalyst, then add ₂₀ ml of toluene, turn on stirring after nitrogen replacement, heat up to 220 ° C and react until no water comes out in the water separator, filter out the catalyst while it is hot, and distill out toluene and toluene under reduced pressure at this temperature. The 2,3-dimethylaniline of the reaction completes the first step reaction;

( ₂ ) add 32.4g (0.2mol) anhydrous FeCl , 93g (1mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 230 ℃ and react until there is no water out in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, then filter while hot, and the filtrate is cooled and solidified into a block product 277g (yield 85.6%) ), the content measured by sampling GC analysis was 89%, and the molecular weight measured by mass spectrometry was 288.

Example 3: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 121g (1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 16.2g (0.1mol) of FeCl to the 1L stainless steel reactor equipped with condenser and water separator ₃ of the supported FeCl catalyst, then add ₂₀ ml of toluene, start stirring after nitrogen replacement, heat up to 230 ° C and react until no water comes out in the water separator, filter out the catalyst while it is hot, and distill out toluene and toluene under reduced pressure at this temperature. The 2,3-dimethylaniline of the reaction completes the first step reaction;

( ₂ ) add 48.6g (0.3mol) anhydrous FeCl , 93g (1mol) aniline and 20mL xylene, after nitrogen replacement, start stirring, be warming up to 240 ℃ of reaction until there is no water in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, then filter while hot, and the filtrate is cooled and solidified into a block product 278 g (yield 89.8%) ), the content measured by sampling GC analysis was 93%, and the molecular weight measured by mass spectrometer was 288.

Example 4: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) 133.1g (1.1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 16.2g (0.1mol) of hydroquinone were added to the 1L stainless steel reactor equipped with a condenser and a water separator. ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 48.6g (0.3mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 250 ℃ and react until no water comes out in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, then filter while hot, and the filtrate is cooled and solidified into a block product 280g (yield 91.4%) ), the content measured by sampling GC analysis was 94%, and the molecular weight measured by mass spectrometry was 288.

Example 5: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 133.1g (1.1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 32.4g (0.2mol) of 2,3-dimethylaniline to the 1L stainless steel reactor equipped with a condenser and a water separator ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 220 ℃ of reaction to no water come out in the water separator, filter out the catalyst while hot, at this temperature, decompression distill out toluene and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 48.6g (0.3mol) anhydrous FeCl ₃ , 139.5g (1.5mol) aniline and 20mL xylene, start stirring after nitrogen replacement, be warming up to 250 ℃ and react until no water comes out in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light components by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 281 g (yield 91.7%) after cooling. ), the content measured by sampling GC analysis was 94%, and the molecular weight measured by mass spectrometry was 288.

Example 6: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 133.1g (1.1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 64.8g (0.4mol) of 2,3-dimethylaniline to the 1L stainless steel reactor equipped with a condenser and a water separator ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 64.8g (0.4mol) anhydrous FeCl ₃ , 139.5g (1.5mol) aniline and 20mL xylene, start stirring after nitrogen replacement, be warming up to 250 ℃ of reaction until there is no water out in the water separator, the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 280 g (yield 88.5% after cooling) ), the content measured by sampling GC analysis was 91%, and the molecular weight measured by mass spectrometry was 288.

Example 7: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 145.2g (1.2mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 64.8g (0.4mol) ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 81g (0.5mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 260 ℃ and react until there is no water out in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light components by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 289 g (yield 85.3% after cooling) ), the content measured by sampling GC analysis was 85%, and its molecular weight was 288 measured by mass spectrometry.

Example 8: Preparation of N-phenyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-1)

(1) Add 145.2g (1.2mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 32.4g (0.2mol) of 2,3-dimethylaniline to the 1L stainless steel reactor equipped with a condenser and a water separator ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 64.8g (0.4mol) anhydrous FeCl ₃ , 167.4g (1.8mol) aniline and 20mL xylene, start stirring after nitrogen replacement, be warming up to 250 ℃ and react until no water comes out in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light components by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 276 g (yield 83.3%) after cooling. ), the content measured by sampling GC analysis was 87%, and its molecular weight was 288 measured by mass spectrometry.

In Examples 1-8, the feeding amount of hydroquinone is all 1 mol, and the difference of other conditions and the experimental results are shown in Table 1.

Table 1: Experimental conditions and experimental results of Examples 1-8

Example 9: N-phenyl-N'-(2,6-dimethyl)phenyl-p-phenylenediamine (Compound I-2)

(1) 133.1g (1.1mol) of 2,6-dimethylaniline, 110.0g (1mol) of hydroquinone, 16.2g (0.1mol) of hydroquinone, 16.2g (0.1mol) of ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,6-dimethylaniline to complete the first step reaction;

(2) add 48.6g (0.1mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 250 ℃ and react until there is no water in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 hour, evaporate the light component by distillation under reduced pressure, then filter while hot, and the filtrate is cooled and solidified into a block product 275g (yield 90.7%) ), the content measured by sampling GC analysis was 95%, and the molecular weight measured by mass spectrometer was 288.

Preparation Example 10: N-phenyl-N'-(2-tert-butyl-4-methyl)phenyl-p-phenylenediamine (Compound I-3)

(1) 179.3g (1.1mol) of 2-tert-butyl-4-methylaniline, 110.0g (1mol) of hydroquinone, 16.2g containing 16.2g were added to the 1L stainless steel reactor equipped with condenser and water separator (0.1mol) FeCl ₃ supported FeCl ₃ catalyst, then add 20 ml of toluene, start stirring after nitrogen replacement, heat up to 240 ° C and react until no water comes out in the water separator, filter out the catalyst while hot, and reduce the pressure at this temperature Distill out toluene and unreacted 2-tert-butyl-4-methylaniline to complete the first step reaction;

(2) add 48.6g (0.1mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 250 ℃ and react until there is no water in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, then filter while hot, and the filtrate is cooled and solidified into a block product 311g (yield 87.6%) ), the content measured by sampling HPLC analysis was 93%, and the molecular weight measured by mass spectrometer was 330.

Preparation Example 11: N-o-tolyl-N'-(2,3-dimethyl)phenyl-p-phenylenediamine (Compound I-4)

(1) 133.1g (1.1mol) of 2,3-dimethylaniline, 110.0g (1mol) of hydroquinone, 16.2g (0.1mol) of hydroquinone were added to the 1L stainless steel reactor equipped with a condenser and a water separator. ) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 230 DEG C and react to no water in the water separator, filter out the catalyst while hot, and distill out toluene under reduced pressure at this temperature and unreacted 2,3-dimethylaniline to complete the first step reaction;

(2) add 48.6g (0.1mol) of anhydrous FeCl ₃ , 128.4g (1.2mol) of o-toluidine and 20mL of xylene, start stirring after nitrogen replacement, be heated to 250 ° C and react until there is no water in the water separator, the reaction end;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 290 g (yield 90.3%) after cooling. ), the content measured by sampling GC analysis was 94%, and the molecular weight detected by mass spectrometry was 302.

Preparation Example 12: N-o-tolyl-N'-(4-tert-butyl)phenyl-p-phenylenediamine (Compound I-5)

(1) Add 163.9g (1.1mol) of 4-tert-butylaniline, 110.0g (1mol) of hydroquinone, 16.2g (0.1mol) of FeCl to the 1L stainless steel reactor equipped with a condenser and a water separator ₃ of the supported FeCl catalyst, then add ₂₀ ml of toluene, turn on stirring after nitrogen replacement, heat up to 240 ° C and react until no water comes out in the water separator, filter out the catalyst while it is still hot, and distill out toluene and toluene under reduced pressure at this temperature. The 4-tert-butylaniline of the reaction completes the first step reaction;

(2) add 48.6g (0.1mol) of anhydrous FeCl ₃ , 128.4g (1.2mol) of o-toluidine and 20mL of xylene, start stirring after nitrogen replacement, be heated to 250 ° C and react until there is no water in the water separator, the reaction end;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 hour, evaporate the light component by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 308 g (yield 87.8%) after cooling. ), the content measured by sampling HPLC analysis was 94%, and the molecular weight measured by mass spectrometry was 330.

Preparation Example 13: N-phenyl-N'-(2,4-di-tert-butyl)phenyl-p-phenylenediamine (Compound I-6)

(1) Add 225.5g (1.1mol) of 2,4-di-tert-butylaniline, 110.0g (1mol) of hydroquinone, 32.4g (0.2 mol) FeCl ₃ load type FeCl ₃ catalyst, add 20ml toluene again, open stirring after nitrogen replacement, be warming up to 240 ℃ of reaction until no water comes out in the water separator, filter out the catalyst while hot, and distill out under reduced pressure at this temperature. Toluene and unreacted 2,4-di-tert-butylaniline complete the first step reaction;

(2) add 48.6g (0.1mol) anhydrous FeCl ₃ , 111.6g (1.2mol) aniline and 20mL xylene, turn on stirring after nitrogen replacement, be warming up to 250 ℃ and react until there is no water in the water separator, and the reaction ends;

(3) Cool down to 90°C, add an aqueous solution containing 0.3 mol of sodium carbonate, keep stirring for 1 h, evaporate the light component by distillation under reduced pressure, filter while hot, and solidify the filtrate into a block product 330 g (yield 82.5% after cooling) ), the content measured by sampling HPLC analysis was 93%, and the molecular weight measured by mass spectrometry was 372.

Test case:

The rubber compositions of Test Examples 1-4 were prepared according to the formula shown in Table 2, which specifically included the following steps:

1. Add natural rubber SCR5 and synthetic rubber BR to the mixer, after kneading for a period of time, add carbon black N550, aromatic oil, zinc oxide, stearic acid and antioxidant (anti-aging agent H, compound I-1, anti-aging agent 3100, compound I-6), continue to knead until the mixing is uniform; the temperature is controlled between 150 ℃ and 160 ℃ during the kneading;

2. Cool the whole mixture to below 100°C, then add the crosslinking system (sulfur S and accelerator NS), and knead the whole mixture; control the temperature during kneading not to exceed 110°C;

3. The obtained rubber composition is calendered into a sheet shape (with a thickness of 2-3 mm), and then vulcanized. The vulcanization temperature is 145° C. and the time is 30 minutes.

The sources of the ingredients in Table 2 are as follows:

SCR5: Xishuangbanna Sinochem Rubber Co., Ltd., natural rubber SCR5;

BR: Nanjing Yangzi Petrochemical Rubber Co., Ltd., synthetic rubber BR9000;

N550: Cabot Corporation, carbon black N550;

Aromatic oil: Shanghai Titan Technology Co., Ltd., general reagent;

Stearic acid: Shanghai Titan Technology Co., Ltd., general reagent, stearic acid (AR);

Zinc oxide: Shanghai Titan Technology Co., Ltd., general reagent, zinc oxide (AR);

NS: Sennics Technology Co., Ltd., vulcanization accelerator NS;

S: Sinopharm Chemical Reagent Company, sublimated sulfur (AR);

Antioxidant H: Sennics Technology Co., Ltd.;

Compound I-1: the compound synthesized in Example 4;

Anti-aging agent 3100: India Acmechem Limited (Acmechem Limited, India);

Compound 1-6: The compound synthesized in Example 13.

Table 2: Formula of rubber composition (unit: part by mass)

formula	Test Example 1	Test case 2	Test case 3	Test Example 4
SCR5	50.0	50.0	50.0	50.0
BR	50.0	50.0	50.0	50.0
N550	50.0	50.0	50.0	50.0
Aromatic oil	5.0	5.0	5.0	5.0
Zinc oxide	5.0	5.0	5.0	5.0
Stearic acid	2.0	2.0	2.0	2.0
Anti-aging agent H	1.5
Compound I-1		1.5
Anti-aging agent 3100			1.5
Compound I-6				1.5
NS	0.8	0.8	0.8	0.8
S	1.5	1.5	1.5	1.5
total	165.8	165.8	165.8	165.8

Anti-ozone aging performance evaluation:

Test pieces of various rubber compositions were subjected to an ozone deterioration test under the conditions of a temperature of 40° C., an ozone concentration of 50 pphm, and an elongation of 20%. The time to appearance of cracks of grades 1c to 4c was recorded. The longer the time to form cracks of the same grade, the better the resistance to ozone aging. The experimental results are shown in Table 3. In Table 3, the numbers in "1c～4c" represent the crack width grade, and the letters represent the crack number grade; 1 means the crack width is greater than 0mm and less than 0.1mm, 2 means the crack width is greater than or equal to 0.1mm and less than 0.2mm, 3 means the crack The width is greater than or equal to 0.2mm and less than 0.4mm, 4 means the crack width is greater than or equal to 0.4mm; c means the number of cracks per centimeter is greater than or equal to 40.

Table 3: Film Ozone Aging Results

	Test Example 1	Test case 2	Test case 3	Test Example 4
Class 1c crack	3h	3h	3h	3h

Class 2c cracks	6h	6h	6h	6h
Class 3c crack	22h	21h	21h	22h
Class 4c crack	50h	60h	54h	62h

It can be seen from Table 3 that the four test films have similar time to primary cracks, and the two films of Test Example 2 and Test Example 4 have the longest time of 4c-level cracks, indicating the ozone resistance of the self-made compounds I-1 and I-6. The aging performance is better than antioxidant H and antioxidant 3100.

Blast performance evaluation:

The surface state of the film was observed one week after the film was made and two weeks later, and the results are shown in Table 4.

Table 4: Test results of blooming performance

	Test Example 1	Test case 2	Test case 3	Test Example 4
1 week	Obvious frosting phenomenon	The surface has not changed	Slight frosting phenomenon	The surface has not changed
Two weeks	Large area hoarfrost	The surface has not changed	Large area hoarfrost	The surface has not changed

As can be seen from Table 4, the two films added with anti-aging agent H (test example 1) and anti-aging agent 3100 (test example 3) obviously had blooming for a period of time, while adding the self-made compound I-1 (test example 2) and The two films of the self-made compound I-6 (Test Example 4) did not bloom after being parked for two weeks, indicating that the compound of the present invention can improve blooming.

Claims (12)

1. A method for preparing an asymmetric diaryl-substituted p-phenylenediamine compound, wherein the asymmetric diaryl-substituted p-phenylenediamine compound has the structure shown in the following formula A:

   

   In formula A, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5, each R _b is independently selected from hydrogen and C1-C6 alkyl, and n is selected from 0-5 Integer; compounds of formula A do not include compounds in which (R _a ) _m substituted phenyl and (R _b ) _n substituted phenyl are the same;

   The method includes:

   (1) in the presence of supported FeCl catalyst, hydroquinone and _formula B compound are reacted to obtain formula C compound:

   

   ( ₂ ) in the presence of anhydrous FeCl , the compound of formula C and the compound of formula D are reacted to obtain the compound of formula A:

   

   Wherein, in the compound of formula B, each R _a is independently selected from hydrogen and C1-C6 alkyl, m is an integer selected from 0-5; in the compound of formula D, each R _b is independently selected from hydrogen and C1-C6 alkyl, n is an integer selected from 0 to 5; the compound of formula B is not the same as the compound of formula D.
2. The method of claim 1, wherein the method has one or more of the following features:

   The carrier _of the supported FeCl catalyst is selected from hydrogen molecular sieve, activated silica and activated alumina;

   The reaction of step (1) is carried out in a non-polar solvent;

   The reaction temperature of step (1) is 200～240 ℃;

   In the reaction system of step (1), the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst to hydroquinone is (0.08-0.4):1;

   In the reaction system of step (1), the molar ratio of the compound of formula B to hydroquinone is (0.8-1.2): 1;

   The reaction of step (1) is carried out in an inert gas atmosphere;

   The reaction of step (2) is carried out in a non-polar solvent;

   The reaction temperature of step (2) is 230～270 ℃;

   The molar ratio of the anhydrous FeCl ₃ added in the step (2) to the hydroquinone added in the step (1) is (0.1-0.5): 1;

   The molar ratio of the compound of formula D added in step (2) to the hydroquinone added in step (1) is (1.0-1.8):1; and

   The reaction of step (2) is carried out in an inert gas atmosphere.
3. The method of claim 2, wherein the method has one or more of the following features:

   In the supported FeCl ₃ catalyst, the mass ratio of FeCl ₃ to the carrier is 1:(5-10);

   The reaction of step (1) is carried out in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane;

   The reaction temperature of step (1) is 220～230 ℃;

   In the reaction system of step (1), the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst to hydroquinone is (0.1-0.25):1;

   In the reaction system of step (1), the molar ratio of the compound of formula B to hydroquinone is (0.9-1.1): 1;

   The reaction of step (1) is carried out in nitrogen atmosphere;

   The reaction of step (2) is carried out in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane;

   The reaction temperature of step (2) is 240～260 ℃;

   The molar ratio of the anhydrous FeCl ₃ added in the step (2) to the hydroquinone added in the step (1) is (0.2-0.3): 1;

   The molar ratio of the compound of formula D added in step (2) to the hydroquinone added in step (1) is (1.2-1.5):1; and

   The reaction of step (2) is carried out in a nitrogen atmosphere.
4. The method of claim ₁ , wherein the carrier of the supported FeCl catalyst is selected from the group consisting of hydrogen-type molecular sieves, activated silica and activated alumina; in the supported FeCl catalyst, the carrier _{of FeCl} and the carrier is The mass ratio is 1: (5-10); the reaction of step (1) is in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and / or in trimethylcyclohexane; the reaction temperature of step (1) is 220-230 ° C; in the reaction system of step (1), the moles of FeCl ₃ and hydroquinone contained in the supported FeCl ₃ catalyst The ratio is (0.1-0.25): 1, and the molar ratio of the compound of formula B to hydroquinone is (0.9-1.1): 1; the reaction of step (1) is carried out in a nitrogen atmosphere; the reaction of step (2) is carried out in toluene , carry out in xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane; the reaction temperature of step (2) is 240-260° C.; the molar ratio of the anhydrous FeCl ₃ added in step (2) to the hydroquinone added in step (1) is (0.2-0.3): 1; the compound of formula D added in step (2) The molar ratio to the hydroquinone added in step (1) is (1.2-1.5):1; and the reaction of step (2) is carried out in a nitrogen atmosphere.
5. A kind of method for preparing following formula I compound:

   

   In formula I, R ₁ and R ₃ are each independently hydrogen or C1-C6 alkyl; R ₂ is C1-C6 alkyl; the compound of formula I does not include R ₁ , R ₂ substituted phenyl and R ₃ substituted phenyl the same compound;

   The method includes:

   (1) react hydroquinone and formula II compound in the presence of supported FeCl catalyst to obtain formula _III compound:

   

   ( ₂ ) in the presence of anhydrous FeCl , the compound of formula III and the compound of formula IV are reacted to obtain the compound of formula I:

   

   Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different; or

   The method includes:

   (1) in the presence of supported FeCl catalyst, hydroquinone and _formula IV compound are reacted to obtain formula III' compound:

   

   ( ₂ ) in the presence of anhydrous FeCl , the compound of formula III ' is reacted with the compound of formula II to obtain the compound of formula I:

   

   Wherein, in the compound of formula II, R ₁ and R ₂ are independently hydrogen or C1-C6 alkyl; in the compound of formula IV, R ₃ is a C1-C6 alkyl; the compound of formula II and the compound of formula IV are different.
6. The method of claim 5, wherein the method has one or more of the following features:

   The carrier _of the supported FeCl catalyst is selected from hydrogen molecular sieve, activated silica and activated alumina;

   The reaction of step (1) is carried out in a non-polar solvent;

   The reaction temperature of step (1) is 200～240 ℃;

   In the reaction system of step (1), the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst to hydroquinone is (0.08-0.4):1;

   In the reaction system of step (1), the molar ratio of the compound of formula II or the compound of formula IV to hydroquinone is (0.8-1.2):1;

   The reaction of step (1) is carried out in an inert gas atmosphere;

   The reaction of step (1) is carried out in a non-polar solvent;

   The reaction temperature of step (2) is 230～270 ℃;

   The molar ratio of the anhydrous FeCl ₃ added in the step (2) to the hydroquinone added in the step (1) is (0.1-0.5): 1;

   The molar ratio of the compound of formula IV or the compound of formula II added in step (2) or the hydroquinone added in step (1) is (1.0-1.8): 1; and

   The reaction of step (2) is carried out in an inert gas atmosphere.
7. The method of claim 6, wherein the method has one or more of the following features:

   In the supported FeCl ₃ catalyst, the mass ratio of FeCl ₃ to the carrier is 1:(5-10);

   The reaction of step (1) is carried out in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane;

   The reaction temperature of step (1) is 220～230 ℃;

   In the reaction system of step (1), the molar ratio of FeCl ₃ contained in the supported FeCl ₃ catalyst to hydroquinone is (0.1-0.25):1;

   In the reaction system of step (1), the molar ratio of the compound of formula II or the compound of formula IV to hydroquinone is (0.9-1.1):1;

   The reaction of step (1) is carried out in nitrogen atmosphere;

   The reaction of step (2) is carried out in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane;

   The reaction temperature of step (2) is 240～260 ℃;

   The molar ratio of the anhydrous FeCl ₃ added in the step (2) to the hydroquinone added in the step (1) is (0.2-0.3): 1;

   The molar ratio of the compound of formula IV or the compound of formula II added in step (2) to the hydroquinone added in step (1) is (1.2-1.5):1; and

   The reaction of step (2) is carried out in a nitrogen atmosphere.
8. The method according to claim 5, wherein, in formula I, R ₁ is hydrogen, R ₂ and R ₃ are each independently C1-C6 alkyl; or R ₃ is hydrogen, and R ₁ and R ₂ are each independently C1-C6 alkyl; or R ₁ , R ₂ and R ₃ are each independently C1-C6 alkyl.
9. The method of claim ₅ , wherein the carrier of the supported FeCl catalyst is selected from the group consisting of hydrogen-type molecular sieves, activated silica and activated alumina; in the supported FeCl catalyst, the carrier _{of FeCl} and the carrier is The mass ratio is 1: (5-10); the reaction of step (1) is in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and / or in trimethylcyclohexane; the reaction temperature of step (1) is 220-230 ° C; in the reaction system of step (1), the moles of FeCl ₃ and hydroquinone contained in the supported FeCl ₃ catalyst The ratio is (0.1-0.25): 1, and the molar ratio of the compound of formula II or the compound of formula IV to hydroquinone is (0.9-1.1): 1; the reaction of step (1) is carried out in a nitrogen atmosphere; step (2) The reaction is carried out in toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, trichlorobenzene, methylcyclohexane, dimethylcyclohexane and/or trimethylcyclohexane; step (2) The reaction temperature is 240-260 ° C; the molar ratio of the anhydrous FeCl added in step ( ₂ ) to the hydroquinone added in step (1) is (0.2-0.3): 1; the addition in step (2) The molar ratio of the compound of formula IV or the compound of formula II to the hydroquinone added in step (1) is (1.2-1.5):1; and the reaction of step (2) is carried out in a nitrogen atmosphere.
10. The method of claim 5, wherein the compound of formula I is selected from the group consisting of:

    

    
11. _A supported FeCl catalyst, characterized in that the carrier of the supported FeCl catalyst is selected from hydrogen _- type molecular sieves, activated silica and activated alumina, and in the supported _FeCl catalyst, _FeCl and the carrier are The mass ratio is 1:(5-10).
12. The supported FeCl ₃ catalyst according to claim 11, wherein the carrier of the supported FeCl ₃ catalyst is prepared by heating reaction between anhydrous FeCl ₃ and the carrier in an alcohol solvent.