CN110734580A

CN110734580A - compounds containing hindered phenol and pentaerythritol structure, synthesis method thereof and application thereof as antioxidant

Info

Publication number: CN110734580A
Application number: CN201810801032.XA
Authority: CN
Inventors: 李广全; 吴建; 段宏义; 李丽; 杨喜棠; 高杜娟; 刘芸; 杨世元; 许云波; 于国滨; 杨柳; 李艳芹; 樊洁; 张红星; 孙建敏
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2018-07-20
Filing date: 2018-07-20
Publication date: 2020-01-31

Abstract

A compound containing hindered phenol and pentaerythritol structure, its synthesis method and its application as antioxidant, the compound containing multifunctional pentaerythritol ester antioxidant is composed of hindered phenol unit, pentaerythritol phosphite unit, trimethylbenzene unit and straight chain segment unit, the length of the straight chain segment unit is controlled to adjust the synergistic action strength of the hindered phenol unit and phosphite unit and the content of effective functional group in unit mass, the trimethylbenzene structure is favorable for preventing the antioxidant compound from separating out from the polymer.

Description

compounds containing hindered phenol and pentaerythritol structure, synthesis method thereof and application thereof as antioxidant

Technical Field

The invention relates to compounds and a synthesis method thereof, in particular to multifunctional compounds which simultaneously contain hindered phenol, phosphite ester and trimethylbenzene in a single molecule and a synthesis method thereof.

Background

Hindered phenolic compounds compete with polymers for peroxy radicals formed in autoxidation, and through transfer of hydrogen atoms, carboxylic acids and stable antioxidant radicals are formed, which have the ability to capture active radicals and can terminate the second kinetic chain of polymer chain oxidation reaction, phosphite compounds decompose peroxides into stable products through conversion from the phosphite compounds themselves into phosphate compounds to protect the polymers, the hindered phenolic compounds and phosphite compounds show a very good synergistic effect in the antioxidation aspect of the polymers, for example, after antioxidant 1010, 1076 and 168 produced by gasoline refining are compounded, is used in antioxidants of products such as polyolefin, ABS resin, synthetic rubber and polyester.

Hindered phenolic antioxidants are generally produced by transesterification under basic conditions. Such as: US4716244, US5481023, US5563291, US6878843, US2003166962, WO198249 describe the preparation of hindered phenolic antioxidants (e.g. antioxidants 1010, 1076, 245 and 1135) using lithium amide, lithium acetate, sodium acetate, magnesium acetate, aluminum triethoxide, zinc acetate, etc. as catalysts. Phosphite antioxidants are generally prepared by reacting alcohol compounds with phosphorus trichloride. Such as: CN200510112503.9, cn200710056079.x, cn200710176407.x describe the process of obtaining phosphite antioxidants by ester exchange of pentaerythritol or nonylphenol with phosphorus trichloride in a solvent.

Meanwhile, when the antioxidant effect is increased by utilizing the mutual synergistic effect of the hindered phenol antioxidant and the phosphite antioxidant, the distance of the two molecules after dispersion in the resin or the rubber is difficult to control, so that the synergistic effect can be influenced, CN103319537A describes bifunctional pentaerythritol ester antioxidants containing both hindered phenol and phosphite structures in the same molecules, and the antioxidant effect is improved by utilizing the synergistic effect of the hindered phenol and the phosphite.

At present, medical infusion bottles and containers in direct contact with food in China are manufactured by adopting special polypropylene or polyethylene resin, the polypropylene or polyethylene material is aged by the action of heat, light, an electric field, rays, metal ions or chemical media and the like in the processes of forming, storing and using, and an antioxidant is required to be added in production, at present, hindered phenol antioxidants and phosphite antioxidants are respectively added into the polypropylene, the adding amount is more than 0.1%, European pharmacopoeia stipulates that the content of a single antioxidant does not exceed 0.3%, and the total amount does not exceed 0.3%.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide antioxidant compounds which contain multiple functional groups and are resistant to precipitation and a synthesis method thereof.

The structure of the compound provided by the invention is as follows:

n is a positive integer of 3 to 16

The purpose of the invention can be realized by the following technical scheme:

A process for synthesizing the antioxidizing agent containing bifunctional groups includes such steps as 2, 6-di-tert-butylphenol, paraformaldehyde, piperazine, ethanediamine, mesitylene, dimethyl sulfate, N-bromosuccinimide, azodiisobutyronitrile, straight-chain diol, phosphorus trichloride, pentaerythritol and boron tribromide solution.

Step 1, etherification of 2, 6-di-tert-butylphenol

Adding 2, 6-di-tert-butylphenol and paraformaldehyde into a reactor, and mixing the components in a molar ratio:

2, 6-di-tert-butylphenol: formaldehyde 1: 1.5-2.0

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from methanol, ethanol, chloroform and toluene;

under the catalytic action of a small amount of piperazine and ethylenediamine, the reaction temperature is 100-150 ℃, the reaction time is 2-5 h, and 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether is generated;

according to a theoretical value, the mole number of the polyformaldehyde and the 2, 6-di-tert-butylphenol is equal, and in practical application, the added polyformaldehyde needs to be obviously excessive so as to ensure the complete reaction of the 2, 6-di-tert-butylphenol. After the reaction is completed, cooling the reaction liquid to room temperature, filtering, washing and drying to obtain pure 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether.

Step 2, condensation reaction

Adding 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether and mesitylene into a reactor according to the mol ratio:

3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether: 3-4: 1 of mesitylene

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from dichloromethane, chloroform, chlorobenzene and carbon tetrachloride;

controlling the reaction temperature to be-20-0 ℃ by adopting an ice salt bath, and slowly dripping concentrated sulfuric acid with the mass concentration of 0.8-0.9% into the reaction solution, wherein the molar ratio of the concentrated sulfuric acid to mesitylene is 1: 2-4. And after the dropwise addition is finished, continuously stirring for 0.5-1 h, pouring the reaction liquid into a separating funnel, standing and collecting the upper layer liquid.

Deionized water, ammonia water and the supernatant liquid obtained by the above reaction were added to a reactor equipped with a stirrer, a thermometer and a condenser. Heating, stirring and heating to 70-90 ℃, and then adding n-heptane and heating to reflux. And cooling to room temperature, and washing the supernatant with deionized water after settling separation until the pH value is 5-8. And cooling the washed clear liquid to 40-50 ℃ in air, cooling the clear liquid to 0-10 ℃ by using an ice water bath, standing the clear liquid for 0.5-1 h, filtering the clear liquid, washing the solid by using n-heptane, and drying the solid at the temperature of 40-50 ℃ to obtain white crystals, namely the product 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene.

According to a theoretical value, the ratio of the 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether to the mesitylene is 3:1, and in practical application, a slight excess of the 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether is added to ensure that three 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether groups are simultaneously connected to the mesitylene in the condensation reaction process.

And 3, protecting phenolic hydroxyl:

adding 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene and dimethyl sulfate into a reactor according to the mol ratio:

1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene: 1: 1.1-2 dimethyl sulfate

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from chlorobenzene, dichloromethane, chloroform and toluene;

under the protection of nitrogen, the reaction temperature is 45-61 ℃, the reaction time is 0.1-2 h, and 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene is generated;

the phenolic hydroxyl protection reaction process is as follows:

in the process of phenolic hydroxyl protection reaction, hydrogen spectrum of nuclear magnetic resonance is used¹H NMR analysis monitors the content of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene in the reaction until no 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene is detected in the reaction; usually every 10 minutesThe clock is monitored times, and the periodic monitoring with unequal intervals can also be adopted.

According to a theoretical value, the dimethyl sulfate is half of that of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, and in practical application, the added dimethyl sulfate is obviously excessive to ensure the complete reaction of the 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene.

And cooling the reaction liquid to room temperature after the reaction is completed, adding a diluted potassium carbonate solution into the reaction liquid for extraction, drying an organic phase, and evaporating to dryness to obtain pure 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene.

Step 4, mono α bromination of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene:

adding 1,3, 5-trimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene and N-bromosuccinimide into a reactor according to the mol ratio,

1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene: 3-4: 1 of N-bromosuccinimide

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from benzene, dichloromethane, chloroform and carbon tetrachloride;

under the protection of nitrogen, under the catalytic action of azodiisobutyronitrile, slowly dropwise adding N-bromosuccinimide into the reaction solution at low temperature, continuously stirring after dropwise adding is finished, raising the temperature of the reaction to 50-77 ℃, and reacting for 2-5 hours to generate 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene.

The equation for the bromination reaction is:

and in the bromination reaction process, observing the color of the reaction solution, and continuing to react for 1-2 hours after the orange color of the reaction solution disappears and white precipitate is generated.

The intermediate product 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene can be purified by a column chromatography method, a developing agent is a mixed solution of dichloromethane and methanol, and after unreacted 1,3, 5-trimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene is collected by column chromatography, mono α bromination reaction can be carried out again.

Step 5, alcoholization reaction of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene

Adding 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene and diol compounds into a reactor according to a molar ratio,

1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene: a diol compound of 1:1.1 to 2

Adding an alkaline substance with the same molar weight as 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene to obtain an alkaline catalyst, wherein the alkaline catalyst can be: sodium hydroxide, potassium carbonate and sodium carbonate.

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from methanol, ethanol, acetone and dimethylformamide;

under the catalytic action of alkaline substances, the reaction liquid is heated to reflux, and the reaction time is 5 to 60 hours, so that the glycol mono- [3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole is generated.

The equation for the bromination reaction is:

diol HO (CH) used in the reaction₂) n in nOH is an integer of 3-16.

During the reaction, different displacement values of the thin-layer chromatography of the reactants and the product on a silica gel plate are utilized, chloroform and methanol are used as developing agents, the gradual lightening of the color point of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene is monitored until the color point is not changed any more, the heating is stopped, the reaction liquid is recovered to the room temperature, then distilled water is added into the reaction liquid for extraction, and after the organic phase is dried, the pure product is obtained by utilizing column chromatography separation.

Step 6, cyclization reaction

Adding phosphorus trichloride and pentaerythritol into a reactor according to the molar ratio,

phosphorus trichloride: 1: 2-2.5, adding a reaction solvent D, reacting at 50-120 ℃ for 2-10 h under the protection of nitrogen and the action of an amine cyclization reaction catalyst to generate dichloropentaerythritol diphosphite;

the reaction equation for phosphite preparation is:

the amine cyclization catalyst used is a well-known conventional product and is a catalyst of the prior art in the field, and generally, the amine cyclization catalyst is selected from of triethylamine, tributylamine, pyridine and weak base anion resin.

According to a theoretical value, phosphorus trichloride is 2 times of that of pentaerythritol, but in practical application, slightly excessive phosphorus trichloride is added, and due to the blowing-off effect of nitrogen in the reaction process, when pentaerythritol completely reacts, blowing-off is continued until phosphorus trichloride completely disappears. At the moment, phosphorus trichloride and pentaerythritol have completely reacted, and the material does not contain phosphorus trichloride and pentaerythritol any more.

The reaction progress was monitored by thin layer chromatography and stopped as the color point of pentaerythritol gradually decreased until it disappeared. The invention does not need to purify the intermediate product of pentaerythritol dichlorophosphite, and directly carries out substitution reaction in the reactor

And 7, substitution reaction:

adding the reaction product obtained in the step 5 into a reactor for cyclization reaction according to the mol ratio,

pentaerythritol: 1: 2-5 parts of diol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole, reacting at 80-140 ℃ for 6-18 h under the protection of nitrogen, and generating pentaerythritol diphosphite

n is a positive integer of 3 to 16

The reaction progress is monitored by thin-layer chromatography, and the reaction is stopped when the color development point of the pentaerythritol dichlorophosphite gradually decreases until the color development point disappears. After removing a large amount of solvent under reduced pressure, the reaction solution is cooled to 0 ℃ and placed for 12 to 24 hours. Crystallizing and separating out the product, filtering to obtain a solid substance, repeatedly washing with isopropanol, and centrifuging at a high speed to obtain a pure product.

Step 8, deprotection reaction of hydroxyl group

Adding the phosphite ester compound obtained in the step 7 and boron tribromide into a reactor according to the mol ratio

Phosphite ester: boron tribromide of 1:2 to 6

The boron tribromide used in the reaction is an ether solution of boron tribromide.

Simultaneously adding a reaction solvent, wherein the reaction solvent is at least selected from dichloromethane, chloroform and carbon tetrachloride.

And (3) adding the phosphite ester obtained in the reaction step into a three-neck flask containing dichloromethane, cooling the temperature of the reaction solution to 0-50 ℃, and slowly adding the dichloromethane solution dissolved with boron tribromide into the flask by using a dropping funnel, wherein the dropping time is 1-5 hours. And after the dropwise addition is finished, the reaction solution is returned to the room temperature and stirred for 2-5 hours.

The reaction equation for deprotection of hydroxyl groups is:

and (3) monitoring the reaction process by using thin-layer chromatography, and stopping the reaction when the color development point of the phosphite ester compound obtained by the reaction in the step 6 gradually becomes smaller until the color development point disappears. And transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7-8, repeatedly extracting, separating an organic layer, drying for 6-24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate to dryness in vacuum to obtain a pure product.

The compound synthesized by the invention can be used as an antioxidant of polyolefin resin, and the compound is added into a polyolefin resin base material according to the mass percent of 0.01-1%.

The invention has the beneficial effects that:

the method is characterized in that a chemical synthesis method is utilized, two functional groups of hindered phenol and phosphite ester are simultaneously introduced into molecules, and the synergistic antioxidation of the two functional groups is increased while the due antioxidation effect of a single functional group is kept, in order to overcome the problem that a single functional group is small in steric hindrance and is easily separated out under the conditions of long-time placement, heat or solvent erosion as the molecular chain is loosely entangled with a polymer molecular chain after being added into polyolefin resin, a trimethylbenzene unit is introduced into the molecule, three hindered phenol structural units are simultaneously connected around benzene ring structures, the steric hindrance of the molecule is remarkably increased, the molecule is easily and stably entangled with the polymer chain of the resin, and the molecule is not easily separated out under the conditions of heat or solvent erosion, and meanwhile, the structure that trimethylbenzenes are simultaneously connected with three hindered phenol units is beneficial to improving the effective content of the hindered phenol units in the same molecule, and the antioxidation effect is further steps.

Nuclear magnetic description

Wherein n is a positive integer from 3 to 16;

1H NMR(500Hz,DMSO)，δ：9.03(s,6H),δ：7.03(s,12H),δ：4.47(s,4H)，δ：4.15(t，6H),δ：3.95(s，12H)，δ：3.57(s,8H)δ：3.47(t，6H)，δ：2.35(t，12H)，δ：1.36-1.50〔m，(4n-8)H〕δ：1.27(S，108H)。

in the nuclear magnetic spectrum of the compound, delta-9.03 represents a hindered phenol structure, and delta-4.47 represents-CH between a benzene ring and an oxygen atom₂-structure (i) (. delta. ═ 4.15) represents-CH on a straight chain adjacent to the oxygen atom to which the P atom is attached₂-structure, δ ═ 3.95 represents-CH between benzene ring and benzene ring₂-structure δ — 3.57 represents pentaerythritol CH₂Structure of- δ ═ 1.29 CH on tert-butyl₃-in the structure of (a).

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

Example 1

293.5g of 2, 6-di-tert-butylphenol, 68.4g of paraformaldehyde, 0.7L of methanol, 2.8g of piperazine and 7.1g of ethylenediamine were added to a 1.5L reaction vessel, the reaction solution was heated to 135 ℃ and the heating was stopped after continuing to heat the reaction solution for 3 hours while stirring. The reaction solution was returned to room temperature and then filtered. The solid product was washed three times with 0.45L methanol each time and the solid was dried to give 299.2g of 3, 5-di-tert-butyl-4-hydroxybenzylmethyl ether as a white product in 84% yield.

1L of dichloromethane is added into a 2.5L three-neck round-bottom flask, 38.9g of mesitylene and 299.2g of 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether are added, the temperature of the reaction solution is controlled at 0 ℃ in an ice salt bath, 104.7g of concentrated sulfuric acid with the concentration of 0.84 percent is added into the reaction solution dropwise with slow stirring for 2.5h, stirring is continued for 1h after the dropwise addition is completed, the reaction solution is poured into a separating funnel, after standing, the upper layer liquid is transferred into a 5L flask, 723g of deionized water and 0.24L of ammonia water are added, the mixture is heated to 85 ℃ under stirring, and 1192g of n-heptane is added and heated to reflux. The reaction solution was cooled to room temperature, and after removing solid matter by filtration, the filtrate was washed with deionized water until the filtrate had a pH of 7.0. Cooling the washed filtrate to 40 ℃ in the air, then cooling the filtrate to 5 ℃ in an ice water bath, standing the cooled filtrate for 1h, filtering the filtrate, washing the solid by 177.5g of n-heptane for three times, and drying the washed solid at 50 ℃ to obtain 224.4g of white crystals, namely the product 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, wherein the yield is 75%.

224.4g of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene and 43.9g of dimethyl sulfate were dissolved in 1.5L of dry chloroform. The reaction mixture was heated to 60 ℃ with stirring in a 2.5L three-necked flask and the reaction was continued for 1.5 hours. The reaction mixture was cooled to 25 ℃ and then extracted repeatedly four times with 1LO.5mol/L potassium carbonate solution, and the organic layer was dried over anhydrous magnesium sulfate for 24 hours. The anhydrous magnesium sulfate desiccant in the solution was removed by filtration, and the solution was evaporated to dryness to give 215.3g of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene as a white solid with a yield of 91%.

215.3g of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene and 1g of azobisisobutyronitrile are added into a 5L three-neck flask with stirring equipment and 3L of carbon tetrachloride, the temperature of the reaction liquid is reduced to 0-5 ℃ by ice-water bath, and then 0.5L of carbon tetrachloride with 14.7g N-bromosuccinimide dissolved is slowly dripped into the reaction liquid by a dropping funnel for 2 hours. After the dropwise addition, the reaction solution was further stirred for 0.5 hour, then the reaction solution was heated to 77 ℃ for reaction for 3 hours, then heating was stopped, the reaction solution was cooled to 0 ℃ and then filtered to remove a white precipitate, the obtained filtrate was subjected to solvent removal under reduced pressure, and crude product column chromatography (developing solvent chloroform, methanol) was carried out to obtain pure 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene 42.9g, with a yield of 58%.

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 6.9g of 1, 3-propanediol were charged in a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further charged in the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. After the drying agent is removed by filtration, the solvent is removed by distillation under reduced pressure to obtain a solid crude product, and the pure 1, 3-propylene glycol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole is obtained by column chromatography (the developing solvent is chloroform and methanol) with the yield of 72 percent of 30.7 g.

1.57g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin are added into a 0.25L three-neck flask, the reaction solution is heated to 50 ℃ under the protection of nitrogen, 3.25g of phosphorus trichloride is slowly dripped into the reaction solution, and the reaction solution is heated to 80 ℃ after the dripping is finished and then the reaction is continued for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 30.7g of 1, 3-propanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, cooled to room temperature, freed of a large amount of solvent in vacuo, left to crystallize at 0 ℃ for 16 hours, and filtered to obtain 14.7g of a product, with a yield of 71%.

Under the protection of nitrogen, 14.7g of bis {1, 3-propanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was charged into a 0.5L three-necked flask containing 0.1L of dichloromethane, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of a dichloromethane solution in which 10.5g of boron tribromide was dissolved in advance was slowly charged into the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 13.8g of pure bis {1, 3-propylene glycol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } yl diphosphite pentaerythritol diphosphite with the yield of 98%.

Example 2

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 9.4g of 1, 5-pentanediol were charged in a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further added to the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. After the drying agent was removed by filtration, the solvent was distilled off under reduced pressure to obtain a crude solid, and column chromatography (chloroform, methanol as a developing solvent) was carried out to obtain 31.7g of pure 1, 5-pentanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole in a yield of 72%.

1.57g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin are added into a 0.25L three-neck flask, the reaction solution is heated to 50 ℃ under the protection of nitrogen, 3.25g of phosphorus trichloride is slowly dripped into the reaction solution, and the reaction solution is heated to 80 ℃ after the dripping is finished and then the reaction is continued for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 31.7g of 1, 5-pentanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, the reaction solution was cooled to room temperature, and after a large amount of solvent was removed in vacuo, the reaction solution was left at 0 ℃ for crystallization for 16 hours, and then filtered to obtain 16.4g of a product, with a yield of 70%.

Under the protection of nitrogen, 16.4g of bis {1, 5-pentanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was charged into a 0.5L three-necked flask containing 0.1L of dichloromethane, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of dichloromethane solution in which 10.2g of boron tribromide was dissolved in advance was slowly charged into the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 15.2g of pure bis {1, 5-pentanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } based pentaerythritol diphosphite, wherein the yield is 97%.

Example 3

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 13.3g of 1, 8-octanediol were charged into a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further added to the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. The drying agent was removed by filtration, and the solvent was removed by distillation under reduced pressure to give a crude solid, which was purified by column chromatography (chloroform, methanol as developing solvent) to give 32.7g of 1, 8-octanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole in 71% yield.

1.54g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin are added into a 0.25L three-neck flask, the reaction solution is heated to 50 ℃ under the protection of nitrogen, 3.19g of phosphorus trichloride is slowly dripped into the reaction solution, and the reaction solution is heated to 80 ℃ after the dripping is finished and then the reaction is continued for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 32.7g of 1, 8-octanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, the reaction solution was cooled to room temperature, and after removing a large amount of solvent in vacuo, the reaction solution was left to crystallize at 0 ℃ for 16 hours, and then filtered to obtain 16.3g of a product, with a yield of 68%.

Under the protection of nitrogen, 16.3g of bis {1, 8-octanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was charged into a 0.5L three-necked flask containing 0.1L of methylene chloride, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of a methylene chloride solution in which 9.9g of boron tribromide was dissolved in advance was slowly charged into the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 15.0g of pure bis {1, 8-octanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } yl diphosphite pentaerythritol diphosphite with the yield of 96%.

Example 4

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 15.8g of 1, 10-decanediol were charged in a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further charged in the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. After the drying agent is removed by filtration, the solvent is removed by distillation under reduced pressure to obtain a solid crude product, and the pure 1, 10-decanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole is obtained by column chromatography (the developing solvent is chloroform and methanol) in 33.2g with the yield of 70%.

Adding 1.52g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin into a 0.25L three-neck flask, heating the reaction solution to 50 ℃ under the protection of nitrogen, then slowly dropwise adding 3.15g of phosphorus trichloride into the reaction solution, raising the temperature of the reaction solution to 80 ℃ after dropwise adding, and continuing to react for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 33.2g of 1, 10-decanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, the reaction solution was cooled to room temperature, and after a large amount of solvent was removed in vacuo, the reaction solution was left at 0 ℃ for crystallization for 16 hours, and then filtered to obtain 16.2g of a product, with a yield of 67%.

Under the protection of nitrogen, 16.2g of bis {1, 10-decanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was added to a 0.5L three-necked flask containing 0.1L of dichloromethane, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of a dichloromethane solution in which 9.7g of boron tribromide was dissolved in advance was slowly added to the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 14.9g of pure bis {1, 10-decanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } yl diphosphite pentaerythritol diphosphite with the yield of 96%.

Example 5

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 20.9g of 1, 14-tetradecanediol were charged into a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further charged into the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. The drying agent was removed by filtration, and the solvent was removed by distillation under reduced pressure to give a crude solid, which was purified by column chromatography (chloroform, methanol as developing solvent) to give 34.0g of 1, 14-tetradecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole in 68% yield.

Adding 1.48g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin into a 0.25L three-neck flask, heating the reaction solution to 50 ℃ under the protection of nitrogen, then slowly dropwise adding 2.95g of phosphorus trichloride into the reaction solution, raising the temperature of the reaction solution to 80 ℃ after dropwise adding, and continuing to react for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 34.0g of 1, 14-tetradecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, the reaction solution was cooled to room temperature, and after a large amount of solvent was removed in vacuo, the reaction solution was left at 0 ℃ for crystallization for 16 hours, and then filtered to obtain 16.4g of a product, with a yield of 66%.

Under the protection of nitrogen, 16.4g of bis {1, 14-tetradecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was charged into a 0.5L three-necked flask containing 0.1L of dichloromethane, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of a dichloromethane solution in which 9.4g of boron tribromide was dissolved in advance was slowly charged into the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 15.0g of pure bis {1, 14-tetradecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } yl diphosphite pentaerythritol diphosphite with the yield of 95%.

Example 6

42.9g of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-methoxybenzyl) benzene and 23.4g of 1, 16-hexadecanediol were charged into a 1L three-necked flask, and 0.4L of an acetone solvent and 6.6g of anhydrous potassium carbonate were further charged into the flask. After the reaction solution was heated under reflux for 6 hours, the heating apparatus was removed and the reaction solution was cooled to 25 ℃. After removing the solvent under reduced pressure, the obtained solid was dissolved in 0.5L of diethyl ether, extracted repeatedly three times with 0.5L of distilled water, and the organic layer was extracted again twice with a dilute sodium hydrogencarbonate solution and a dilute hydrochloric acid solution and then dried over anhydrous magnesium sulfate for 12 hours. The drying agent was removed by filtration, and the solvent was removed by distillation under reduced pressure to give a crude solid, which was purified by column chromatography (chloroform, methanol as developing solvent) to give 33.4g of 1, 16-hexadecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole in 65% yield.

Adding 1.41g of pentaerythritol, 0.05L of toluene and 0.1g of weakly basic anion resin into a 0.25L three-neck flask, heating the reaction solution to 50 ℃ under the protection of nitrogen, then slowly dropwise adding 2.81g of phosphorus trichloride into the reaction solution, raising the temperature of the reaction solution to 80 ℃ after dropwise adding, and continuing to react for 5 hours. The reaction progress is monitored by thin layer chromatography, and heating is stopped when the color development points of pentaerythritol and phosphorus trichloride gradually decrease until they disappear. After the reaction solution was returned to room temperature, 33.4g of 1, 16-hexadecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole was added to the reaction solution, while 0.05L of tributylamine was added as a catalyst for substitution reaction, heated to 110 ℃ for 10 hours, the reaction solution was cooled to room temperature, and after a large amount of solvent was removed in vacuo, the reaction solution was left at 0 ℃ for crystallization for 16 hours, and then filtered to obtain 16.0g of a product, with a yield of 66%.

Under the protection of nitrogen, 16.0g of bis {1, 16-hexadecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole } yl pentaerythritol diphosphite was added to a 0.5L three-necked flask containing 0.1L of dichloromethane, the temperature of the reaction solution was cooled to-20 ℃ and then 0.1L of a dichloromethane solution in which 8.9g of boron tribromide was dissolved in advance was slowly added to the flask through a dropping funnel for 2 hours. After the completion of the dropwise addition, the reaction mixture was returned to room temperature and stirred for 5 hours. Transferring the reaction solution to a separating funnel, adding distilled water with the pH value of 7.0-8.0, repeatedly extracting for three times, separating an organic layer, drying for 24 hours by using anhydrous magnesium sulfate, filtering to remove a drying agent, and evaporating the filtrate in vacuum to obtain 14.7g of pure bis {1, 16-hexadecanediol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxy) ] anisole } yl diphosphite pentaerythritol diphosphite with the yield of 95%.

Application example:

the formula sample: 100 parts by mass of polypropylene powder and 1 part by mass of an auxiliary product are uniformly mixed in a high-speed mixer, and are extruded and granulated by a double-screw extruder, wherein the screw rotating speed of the double-screw extruder is 120 revolutions per minute, and the material melt temperature is 220 ℃. The oxidation resistance of the formulation samples was measured. The antioxidants 1010 and 168 used in comparative examples 2 and 3 were commercially available, and the antioxidants used in comparative examples 4, 5, 6, 7, 8, 9 were dipentaerythritol bis [1, 3-propanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] yl diphosphite, dipentaerythritol bis [1, 5-pentanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] yl diphosphite, pentaerythritol bis [1, 8-octanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] yl diphosphite, pentaerythritol bis [1, 10-decanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] yl diphosphite, dipentaerythritol bis [1, 14-tetradecanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] based pentaerythritol diphosphite and bis [1, 16-hexadecanediol mono- (3, 5-di-tert-butyl, 4-hydroxy) anisole ] based pentaerythritol diphosphite were synthesized by the method described in CN 103319537A. Accurately weighing 30g of the granulated sample, placing the weighed sample into a conical flask, adding 150ml of deionized water, placing the conical flask into a high-temperature sterilizer, heating the conical flask to 120 +/-2 ℃, keeping the temperature for 30min, then recovering the room temperature, passing the deionized water through a solid phase extraction column, and sequentially eluting the deionized water with 12ml of methanol and 8ml of tetrahydrofuran. An Agilent 1260 liquid chromatograph is adopted, concentration curves of different additives are established in advance, the curves are used as the antioxidant precipitation amount of a mapping test, and the results are shown in the table.

The results are shown in the following table:

TABLE 1 antioxidant and antistatic testing of formulation samples

It can be seen from the results in table 1 that when no antioxidant is added to the polypropylene in comparative example 1, the product is very easily oxidized, which is indicated by large melt index, high yellow index and short initial powdering time, when 1010 or 168 antioxidant is added to the polypropylene in comparative example 2 and comparative example 3, the product shows the oxidation resistance of , and simultaneously the migration amount of the additive is large, comparative examples 4, 5, 6, 7, 8 and 9 correspond to application examples 1, 2, 3, 4, 5 and 6, which are by one, the antioxidant molecular structures are similar, and the antioxidant ester antioxidants both containing bifunctional groups show better antioxidant effects.

The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1, A compound comprising a hindered phenol and pentaerythritol, wherein the formula is:

wherein n is a positive integer from 3 to 16.

A method of synthesizing the compound of claim 1, comprising the steps of:

step 1, etherification of 2, 6-di-tert-butylphenol: the molar ratio of 2, 6-di-tert-butylphenol: adding 2, 6-di-tert-butylphenol and paraformaldehyde into a reactor, simultaneously adding a reaction solvent, reacting at the temperature of 100-150 ℃ for 2-5 h under the catalytic action of 0.1-1.0 ml of piperazine and ethylenediamine, cooling the reaction solution to room temperature after the reaction is completed, filtering, washing and drying to obtain pure 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether;

step 2, condensation reaction: the molar ratio of 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether: adding 3, 5-di-tert-butyl-4-hydroxybenzyl methyl ether and mesitylene into a reactor, simultaneously adding a reaction solvent, controlling the reaction temperature to be-20-0 ℃, dropwise adding concentrated sulfuric acid into the reaction solution, wherein the molar ratio of the concentrated sulfuric acid to the mesitylene is 1: 2-4, then continuously stirring for 0.5-1 h, standing the reaction solution, collecting the upper layer liquid, adding deionized water, ammonia water and the upper layer liquid obtained by the reaction into the reactor, heating, stirring and heating to 70-90 ℃, then adding n-heptane, heating to reflux, cooling to room temperature, washing the upper layer clear liquid with the deionized water after separation until the pH value is 5-8, cooling the washed clear liquid to 40-50 ℃, then cooling to 0-10 ℃, standing for 0.5-1 h, filtering, washing the solid with the n-heptane, drying at 40-50 ℃ to obtain a white crystal product 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene;

and 3, protecting phenolic hydroxyl: 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene: adding dimethyl sulfate (1: 1.1-2) into a reactor, adding a reaction solvent, reacting at 45-61 ℃ for 0.1-2 h under the protection of nitrogen, cooling the reaction solution to room temperature after the reaction is completed, adding a diluted potassium carbonate solution into the reaction solution, extracting, drying the organic phase, and evaporating to obtain pure 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene;

step 4, mono α bromination of 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene, namely adding 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene and N-bromosuccinimide into a reactor according to the molar ratio of 3-4: 1, simultaneously adding a reaction solvent, dropwise adding the N-bromosuccinimide into a reaction solution under the catalytic action of azodiisobutyronitrile under the protection of nitrogen, continuously stirring, raising the reaction temperature to 50-77 ℃, and reacting for 2-5 hours to generate 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene;

and step 5, carrying out alcoholization reaction on 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene: the molar ratio of 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tri (3, 5-di-tert-butyl-4-methoxybenzyl) benzene: adding a diol compound which is 1: 1.1-2 into a reactor, adding an alkaline substance in an equimolar amount with 1-bromomethyl-3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) benzene, simultaneously adding a reaction solvent, heating the reaction solution to reflux, and reacting for 5-60 hours to generate diol mono- [3, 5-dimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-methoxybenzyl) ] anisole;

step 6, cyclization reaction: adding phosphorus trichloride and pentaerythritol into a reactor according to the mol ratio of phosphorus trichloride: 1: 2-2.5, adding a reaction solvent, reacting at 50-120 ℃ for 2-10 h under the protection of nitrogen and the action of a catalyst to generate dichloropentaerythritol diphosphite;

and 7, substitution reaction: adding the reaction product obtained in the step 5 into a reactor for cyclization reaction, wherein the molar ratio of pentaerythritol: under the protection of nitrogen, reacting diol mono (3, 5-di-tert-butyl, 4-methoxy) anisole at 80-140 ℃ for 6-18 h to generate pentaerythritol diphosphite;

and 8, deprotection reaction of hydroxyl: and (3) adding the phosphite ester compound obtained in the step (7) and boron tribromide into a reactor, wherein the molar ratio of the phosphite ester compound to the boron tribromide is phosphite ester: and (2) boron tribromide is 3: 1-3, the boron tribromide used in the reaction is an ether solution of the boron tribromide, a reaction solvent is added at the same time, the pentaerythritol diphosphite ester obtained in the previous step is added into a reaction container containing dichloromethane, the temperature of the reaction liquid is reduced to 0 ℃ -minus 50 ℃, the dichloromethane solution in which the boron tribromide is dissolved in advance is dripped into the reaction container, the dripping time is 1-5 hours, and after the dripping is finished, the reaction liquid is returned to the room temperature and then is stirred for 2-5 hours, so that the antioxidant compound containing the bifunctional pentaerythritol ester is prepared.

3. The process of claim 2 wherein in step 5 the basic catalyst is sodium hydroxide, potassium carbonate or sodium carbonate.

4. The method according to claim 2, wherein the number of carbon atoms of the diol compound in the step 5 is a positive integer of 3 to 16.

5. The method of claim 2, wherein the solvent added in step 1 is selected from of methanol, ethanol, chloroform and toluene.

6. The method of claim 2, wherein the solvent added in step 2 is selected from of benzene, dichloromethane, chloroform and carbon tetrachloride.

7. The method of claim 2, wherein the solvent added in step 3 is selected from kinds of chlorobenzene, dichloromethane, chloroform and toluene.

8. The method of claim 2, wherein the solvent added in step 4 is selected from of benzene, dichloromethane, chloroform and carbon tetrachloride.

9. The method of claim 2, wherein the solvent added in step 5 is selected from of methanol, ethanol, acetone, and dimethylformamide.

10. The method of claim 2, wherein the solvent added in step 6 is selected from solvents selected from toluene, xylene, benzene, chlorobenzene, dichloromethane, and ethyl acetate.

11. The method of claim 2, wherein the solvent added in step 8 is selected from of dichloromethane, chloroform and carbon tetrachloride.

Use of compounds according to claim 1, characterized in that said compounds are used as antioxidants for polyolefin resins.

13. The use according to claim 12, wherein the compound is added to the polyolefin resin base in a mass percentage of 0.01% to 1%.