WO2019174360A1 - Antioxidant 1076 synthesizing process - Google Patents

Abstract

Provided in the present invention is a method for organically synthesizing antioxidant 1076, which is 3(3,5-di-tert-butyl-4-hydroxyphenyl) n-octadecanol propionate. The preparation method comprises the following steps: with a mixture of ethylene glycol and toluene serving as a solvent, and with 3-(3,5-di-tert-butyl-4-hydroxyphenyl)methyl propionate and octadecanol serving as reactants, a catalyst is added for a reaction to produce 3(3,5-di-tert-butyl-4-hydroxyphenyl) n-octadecanol propionate. In the present invention, the mixture serves as the solvent and the catalyst is added in batches during the reaction process, the amount of the catalyst used is small in the reaction provided in the present invention for preparing 3(3,5-di-tert-butyl-4-hydroxyphenyl) n-octadecanol propionate, the reaction temperature is low, the purity of the product produced is high, and the yield of the organic synthesis method is kept as high as 92% or more during pilot tests.

Description

Antioxidant 1076 synthesis process Technical field

The invention relates to the field of organic chemical technology, in particular to an organic synthesis method of an antioxidant 1076, namely n-octadecanol 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

Background technique

An antioxidant is an organic compound that inhibits or retards the thermal oxidation of high polymers and other organic compounds in the air. It is usually very effective by adding a small concentration of 1% antioxidant. For example, foods are susceptible to oxidative deterioration, and small amounts of antioxidants can be added to extend their storage time. Polymer materials such as plastics, synthetic fibers and rubber are prone to thermal oxygen degradation reaction. The addition of antioxidants can maintain the excellent properties of polymer materials and prolong the service life. The addition of antioxidants should be closer to the aging cycle, for example, in polymer drying. Before powdering

3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester, ie antioxidant 1076, having the formula: C35H62O3, molecular weight: 530.86, structural formula (I):

3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester, which is an excellent unterminated hindered phenolic antioxidant with a white or yellowish solid powder. It is easily soluble in organic solvents such as benzene, chloroform, cyclohexane, acetone and esters. It is slightly soluble in ethylene glycol, ethanol and mineral oil. It is insoluble in water and can inhibit the oxidative degradation and thermal degradation of many organic compounds and polymers. It has been widely used in polyolefins, polyamides, polyesters, ABS resins, synthetic rubbers, greases, coatings, lubricants, etc., and is also suitable for certain food packaging materials. It has good compatibility, high anti-oxidation efficiency, no coloring, no pollution, washing resistance, extraction, heat resistance, low volatility, etc. It has synergistic effect with UV absorber.

Although the antioxidant 1076 has been industrially produced, the production process is old, the post-processing is complicated, the cost is high, and the pollutants are discharged. In the traditional process, sodium glycol sodium is used as a catalyst, and dimethyl sulfoxide is used as a solvent, and the reaction yield is low, which is generated by pollutants and pollutes the environment. At present, there is an improved production method using dioctyltin oxide as a catalyst, the reaction conditions are more moderate, the product yield is improved, the process is relatively simple, and environmentally friendly, but the use of the dioctyltin oxide catalyst in the preparation process is used. The amount is 1.5% (mass fraction) of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate, and the reaction temperature is also relatively high, which needs to reach 130-135 ° C, due to the comparison of catalyst prices. High, so the product yield is improved on the basis of reducing the amount of catalyst and lowering the reaction temperature. It has been reported that the laboratory yield of antioxidant 1076 can reach 97%, but it has been verified that the method is in the middle of the pilot process. For various practical reasons, the yield can only reach 70-80%, which means that there is still a certain gap between the effect achieved by the laboratory method and the effect achieved in actual production. Therefore, it is urgent to provide a method for improving the yield of the synthetic antioxidant 1076.

Summary of the invention

In order to solve the above problems, the present invention aims to provide an organic synthesis method in which the amount of the catalyst is small, the catalyst is cheap and easy to obtain, the reaction temperature is low, the purity of the obtained product is high, and the yield in the pilot test is still as high as 92% or more.

The technical solution of the present invention is as follows:

Organic synthesis of n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate, the 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propane The chemical structural formula of the acid n-stearyl alcohol ester is as shown in formula I:

A method of synthesizing the n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, the method comprising the following synthetic route (A):

The method includes the following steps:

(1) Add a certain amount of the reactant 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid methyl ester and an appropriate amount of solvent A in a three-necked flask, and then add the rotor and fix the reflux condenser tube. On a three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is placed in an ice bath for a certain period of time to obtain a reaction liquid;

(3) adding a certain amount of catalyst A to the reaction liquid of the step (2), and after reacting for one hour, adding an appropriate amount of the reactant stearyl alcohol, removing the ice bath, and placing the three-necked flask containing the reaction liquid in the oil bath. After reacting at 80-100 ° C for 3 hours, it was cooled to 60 ° C, crystallized, and suction filtered to give a product.

In the above step (1), the solvent A is a mixed solution of ethylene glycol and toluene, and the ratio of the volume of the two is 1-5:10-200.

In some embodiments, the solvent A used in the step (1) is a mixed solution of ethylene glycol and toluene in a volume ratio of 1:10.

In other embodiments, the solvent A used in the step (1) is a mixed solution of ethylene glycol and toluene in a volume ratio of 2:100.

In some preferred embodiments, the solvent A used in the step (1) is a mixed solution of ethylene glycol and toluene in a volume ratio of 5:200.

The ratio of the amount of the reactant methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate in the above step (1) to the amount of the stearyl alcohol in the step (3) is 1-1.2:1.

The total mass of the reactant 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate in the above step (1) and the reactant stearyl alcohol in the step (3) and the total amount of the solvent The volume ratio is 6-12: 100-250 (g/mL).

The reaction time in the above step (2) in the ice bath condition is 10 to 30 min; preferably, 12 to 28 mim; further preferably 15 to 15 min.

The catalyst A added in the above step (3) may be selected from the group consisting of cesium carbonate, cesium carbonate, dibutyltin oxide, dibutyltin dilaurate, tributyltin acetate, tetramethyl titanate, tetrabutyl titanate, titanium. One or more of isobutyl acrylate, zirconium oxide and tetrabutyl zirconate;

Preferably, the catalyst A added in the above step (3) may be selected from the group consisting of dibutyltin dilaurate, tributyltin acetate, tetramethyl titanate, tetrabutyl titanate, isobutyl titanate, zirconia and zirconium. One or more of tetrabutyl phthalate;

Further preferably, the catalyst A added in the above step (3) may be selected from one or more of tetramethyl titanate, tetrabutyl titanate, isobutyl titanate, zirconia and tetrabutyl zirconate. ;

Still more preferably, the catalyst A added in the above step (3) may be selected from one or more of tetramethyl titanate, tetrabutyl titanate, isobutyl titanate and tetrabutyl zirconate.

In some preferred embodiments, the catalyst A in the step (3) is selected from the group consisting of tetrabutyl titanate and tetrabutyl zirconate in a mass ratio of 1:1.

In another preferred embodiment, the catalyst A in the step (3) is selected from the group consisting of tetramethyl titanate and tetrabutyl titanate in a mass ratio of 1:1.

The total amount of the catalyst used is 0.25-0.3% (mass fraction) of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

In the present application, when the mixed catalyst A is added, the catalyst A is added in stages, that is, in the step (3), first, half of the catalyst of the total amount of the catalyst A is added to the reaction liquid, and then the other half of the catalyst A is added after the addition of the stearyl alcohol. .

In another aspect, the present invention provides a method for synthesizing the above-mentioned starting material methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, the synthesis step is:

A. The reactant 2,6-di-tert-butylphenol and the catalyst B are added to a three-necked flask equipped with a N ₂ gas pipe, a rotor and a dropping funnel, and melted under nitrogen gas protection and heating to obtain a reactant;

B. When the reaction temperature reaches 60-80 ° C, the reaction methyl ester is added dropwise to the reaction product of the step A. After the completion of the dropwise addition, the reaction is continued for 0.5 hour, and then the temperature is raised to 90-100 ° C to continue the reaction for 1 hour, followed by cooling. At 80 ° C, the reaction solution is adjusted to neutral with hydrochloric acid, crystallized, and filtered to obtain a product;

The mass ratio of the reactant 2,6-di-tert-butylphenol in the above step A to the methyl acrylate of the reactant in the step B is 5:2.

The total amount of the catalyst B used in the above step B is 0.2 to 0.25% (mass fraction) of the total mass of the reactant 2,6-di-tert-butylphenol and methyl acrylate.

The catalyst B added in the above step B may be selected from one or more of zinc isooctanoate, zinc carbonate, zinc acetate, dibutyltin dilaurate, tributyltin acetate, stannous octoate and dibutyltin diacetate;

Preferably, the catalyst B added in the above step B may be selected from one or more of zinc carbonate, zinc acetate, tributyltin acetate, stannous octoate and dibutyltin diacetate;

Further preferably, the catalyst B added in the above step B may be selected from one or more of zinc carbonate, zinc acetate, tributyltin acetate and stannous octoate;

In some preferred embodiments, the catalyst B in step B is selected from the group consisting of a mixture of zinc carbonate and tributyltin acetate in a mass ratio of 1:1.5.

In another preferred embodiment, the catalyst B in step B is selected from the group consisting of zinc acetate and stannous octoate in a mass ratio of 1:2.

The beneficial effects of the present invention are as follows:

The invention greatly improves the reaction efficiency and reduces the yield and purity of the reaction product by adjusting the kind of the reaction catalyst and the solvent required for the reaction, thereby reducing the amount of the catalyst, and does not generate polluting gas and pollutants, which is beneficial to the invention. protect environment. It provides a possibility for large-scale industrial production of n-octadecanol 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

Specific implementation

explain:

The symbol V _ethylene appears in the text to indicate the volume of ethylene glycol, and V _toluene represents the volume of toluene.

Example 1 A method for synthesizing a raw material methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

The synthesis steps are:

(1) In a three-necked flask equipped with a N ₂ gas pipe, a rotor, and a dropping funnel, 20.6 g of a reactant 2,6-di-tert-butylphenol and a mixture of zinc carbonate and tributyltin acetate in a mass ratio of 1:1.5 were added. 0.072 g, which is melted under nitrogen protection and heating to obtain a reactant;

(2) When the reaction temperature reached 70 ° C, 8.24 g of the reactant methyl acrylate was added dropwise to the reaction product of the step (1), and after the completion of the dropwise addition, the reaction was continued for 0.5 hour, and then the temperature was raised to 90 ° C to continue the reaction for 1 hour. Cooling to 80 ° C, adjusting the reaction solution to neutral with hydrochloric acid, crystallization, suction filtration, to obtain a product;

The final product yield was 99% and the purity without recrystallization was as high as 99.5%.

The catalysts used in Examples 2-5 were two catalysts with a mass ratio of 1:1.

Example 2 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester was synthesized as follows:

(1) A reaction product of methyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate (2.92 g) and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) were placed in a three-necked flask. 10) Mix 150 mL of the solution, then add the rotor, and fix the reflux condenser on a three-necked flask, vacuum treatment under nitrogen protection, and cycle 3 times;

(2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is subjected to an ice bath for 15 minutes to obtain a reaction liquid;

(3) To the reaction liquid of the step (2), 0.00365 g of tetrabutyl titanate and tetrabutyl zirconate of a mass ratio of 1:1 were added, and after reacting for one hour, 2.70 g of the reactant stearyl alcohol was added, and then added. 0.00365 g of tetrabutyl titanate and tetrabutyl zirconate with a mass ratio of 1:1, the ice bath was removed, and the three-necked flask containing the reaction liquid was placed in an oil bath, and reacted at 80 ° C for 3 hours, then cooled to Crystallization at 60 ° C, suction filtration to obtain the product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield is 98.5% and the purity is as high as 99.6%.

Example 3 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester was synthesized as follows:

(1) The reactant 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid methyl ester 4.38 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) were added to a three-necked flask. 50) mixing the solution 200mL, after adding the rotor, and fixing the reflux condenser on the three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is subjected to an ice bath for 15 minutes to obtain a reaction liquid;

(3) Adding 0.00548 g of tetrabutyl titanate and tetrabutyl zirconate in a mass ratio of 1:1 to the reaction liquid of the step (2), and reacting for one hour, adding 4.05 g of the reactant stearyl alcohol, and then adding 0.00548g of tetrabutyl titanate and tetrabutyl zirconate with a mass ratio of 1:1, the ice bath was removed, and the three-necked flask containing the reaction liquid was placed in an oil bath, and reacted at 80 ° C for 3 hours, then cooled to Crystallization at 60 ° C, suction filtration to obtain the product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 98.6% and the purity was as high as 99.7%.

Example 4 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester was synthesized as follows:

(1) The reactant 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid methyl ester 4.38 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) were added to a three-necked flask. 10) Mix 150 mL of the solution, then add the rotor, and fix the reflux condenser on a three-necked flask, vacuum treatment under nitrogen protection, and cycle 3 times;

(2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is placed in an ice bath for 24 minutes to obtain a reaction liquid;

(3) adding 0.00548 g of tetrabutyl titanate and tetramethyl titanate in a mass ratio of 1:1 to the reaction liquid of the step (2), and reacting for one hour, adding 4.05 g of the reactant stearyl alcohol, and then adding 0.00548g of tetrabutyl titanate and tetrabutyl zirconate with a mass ratio of 1:1, the ice bath was removed, and the three-necked flask containing the reaction liquid was placed in an oil bath, and reacted at 80 ° C for 3 hours, then cooled to Crystallization at 60 ° C, suction filtration to obtain the product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 99.2% and the purity was as high as 99.6%.

Example 5 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester was synthesized as follows:

(1) A reaction mixture of methyl 5-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate 5.256 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) was placed in a three-necked flask. 50) mixing the solution 200mL, after adding the rotor, and fixing the reflux condenser on the three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated reaction-containing three-necked flask obtained in the step (1) is subjected to an ice bath for 20 minutes to obtain a reaction liquid;

(3) To the reaction liquid of the step (2), 0.00657 g of tetrabutyl titanate and tetramethyl titanate were added in a mass ratio of 1:1, and after reacting for one hour, 4.05 g of the reactant stearyl alcohol was added, and then added. 0.00657g of tetrabutyl titanate and tetrabutyl zirconate with a mass ratio of 1:1, the ice bath was removed, and the three-necked flask containing the reaction liquid was placed in an oil bath, and reacted at 80 ° C for 3 hours, then cooled to Crystallization at 60 ° C, suction filtration to obtain the product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 99.6% and the purity was as high as 99.8%.

The catalyst used in Examples 6-9 is a catalyst

Example 6 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester was synthesized as follows:

(1) A reaction mixture of methyl 5-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate 5.256 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) was placed in a three-necked flask. 40) 150mL of the mixed solution, after adding the rotor, and the reflux condenser is fixed on the three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated reaction-equipped three-necked flask obtained in the step (1) is subjected to an ice bath for 25 minutes to obtain a reaction liquid;

(3) 0.00657 g of tetrabutyl titanate was added to the reaction liquid of the step (2), and after reacting for one hour, 4.05 g of the reaction stearyl alcohol was added, and then 0.00657 g of tetrabutyl titanate was added, and the ice bath was removed. The three-necked flask containing the reaction liquid was placed in an oil bath, reacted at 90 ° C for 3 hours, cooled to 60 ° C, crystallized, and suction filtered to obtain a product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 94.2% and the purity was as high as 97.4%.

Example 7 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester was synthesized as follows:

(1) A reaction mixture of methyl 5-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate 5.256 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) was placed in a three-necked flask. 10) Mixing 250 mL of the solution, then adding the rotor, and fixing the reflux condenser to a three-necked flask, vacuum-treating under nitrogen protection, and circulating 3 times;

(2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is subjected to an ice bath for 15 minutes to obtain a reaction liquid;

(3) 0.00657 g of isobutyl titanate was added to the reaction liquid of the step (2), and after reacting for one hour, 4.05 g of the reactant stearyl alcohol was added, and then 0.00657 g of isobutyl titanate was added, and the ice bath was removed. The three-necked flask containing the reaction liquid was placed in an oil bath, reacted at 85 ° C for 3 hours, cooled to 60 ° C, crystallized, and suction filtered to obtain a product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 95.2% and the purity was as high as 97.8%.

Example 8 A method for synthesizing 3-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. The synthesis steps are as follows:

(1) A reaction product of methyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate (2.920 g) and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) were placed in a three-necked flask. 10) 200mL of the mixed solution, after adding the rotor, and the reflux condenser is fixed on the three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated reaction-containing three-necked flask obtained in the step (1) is subjected to an ice bath for 20 minutes to obtain a reaction liquid;

(3) 0.00367 g of tetrabutyl zirconate was added to the reaction liquid of the step (2), and after reacting for one hour, 2.70 g of the reaction stearyl alcohol was added, and then 0.00367 g of isobutyl titanate was added, and the ice bath was removed. The three-necked flask containing the reaction liquid was placed in an oil bath, reacted at 80 ° C for 3 hours, cooled to 60 ° C, crystallized, and suction filtered to obtain a product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 93.9% and the purity was as high as 96.8%.

Example 9 A method for synthesizing 3-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. The synthetic steps are as follows:

(1) A reaction product of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate 7.018 g and ethylene glycol and toluene (V _{ethylene glycol} : V _toluene = 1) were placed in a three-necked flask. 40) mixing the solution 250mL, after adding the rotor, and fixing the reflux condenser on the three-necked flask, vacuum treatment under nitrogen protection, cycle 3 times;

(2) The vacuum-treated reaction-containing three-necked flask obtained in the step (1) is subjected to an ice bath for 20 minutes to obtain a reaction liquid;

(3) 0.00877 g of tetrabutyl zirconate was added to the reaction liquid of the step (2), and after reacting for one hour, 5.41 g of the reaction stearyl alcohol was added, and then 0.00877 g of isobutyl titanate was added, and the ice bath was removed. The three-necked flask containing the reaction liquid was placed in an oil bath, reacted at 80 ° C for 3 hours, cooled to 60 ° C, crystallized, and suction filtered to obtain a product.

The synthesis of methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate is shown in Example 1.

The final product yield was 94.5% and the purity was as high as 97.3%.

Comparative Example 1 A method for synthesizing 3-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate was synthesized as follows:

The difference from Example 5 was that the solvent used in the step (1) was a single solvent ethylene glycol, and the other steps were the same as in the fifth embodiment.

The final product yield was 85.3% and the purity was as high as 92.4%.

Comparative Example 2 A method for synthesizing 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester was synthesized as follows:

The difference from Example 5 was that the solvent used in the step (1) was a single solvent toluene, and the other steps were the same as in the example 5.

The final product yield was 85.7% and the purity was as high as 93.6%.

Comparative Example 3 A method for synthesizing 3-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate was synthesized as follows:

The difference from Example 5 was that no vacuum treatment was carried out in the step (1), and the other steps were the same as in the fifth embodiment.

The final product yield was 83.6% and the purity was as high as 94.7%.

Comparative Example 4 A synthetic procedure for the synthesis of n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was carried out as follows:

The difference from Example 5 was that the catalyst was added in one step in the step (3), and the other steps were the same as in the example 5.

The final product yield was 85.6% and the purity was as high as 96.2%.

Comparative Example 5 A synthetic procedure for the synthesis of n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate was carried out as follows:

The difference from Example 5 was that the mass ratio of the two catalysts in the step (3) was 1:4, and the other steps were the same as those in the example 5.

The final product yield was 80.4% and the purity was as high as 93.5%.

Comparative Example 6 A synthetic procedure for the synthesis of n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate was carried out as follows:

The difference from Example 5 was that the mass ratio of the two catalysts in the step (3) was 5:1, and the other steps were the same as those in the example 5.

The final product yield was 81.4% and the purity was as high as 94.0%.

Comparative Example 7 Synthesis of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid n-octadecyl ester The synthetic steps were as follows:

Methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate and stearyl alcohol, a catalyst and toluene were added to a three-necked flask equipped with a rotor and a thermometer, and a vacuum was applied through a nitrogen gas. The mixture was circulated three times, heated to 80 ° C for 5 hours, cooled to 60 ° C, crystallized, and suction filtered to obtain a product.

The final product yield was 83.2% and the purity was as high as 94.5%.

Result test

Instance Yield(%) purity(%) Instance Yield(%) purity(%) Example 2 98.5 99.6 Comparative example 1 88.3 94.4 Example 3 98.6 99.7 Comparative example 2 88.7 93.6 Example 4 99.2 99.6 Comparative example 3 85.6 94.7 Example 5 99.6 99.8 Comparative example 4 88.6 96.2 Example 6 94.2 97.4 Comparative example 5 80.4 93.5 Example 7 95.2 97.8 Comparative example 6 81.4 94.0 Example 8 93.9 96.8 Comparative example 7 82.2 94.5 Example 9 94.5 97.3

Through the above experimental results, the preparation method for preparing the antioxidant 1076 provided by the present invention can be obtained, and the product yield can be as high as 93% or more, and the recrystallization purity can be as high as 96% or more. In a preferred embodiment of the present invention (Examples 2-5), the catalyst is mixed and used in the two catalysts provided by the present invention, and the mass ratio is controlled to be 1:1, which greatly improves the yield and purity of the antioxidant 1076. The rate can be as high as 99.2%, the purity can be as high as 99.8%; and the two catalysts are also used in the comparative examples 5-6, but the mass ratio is different from the mass ratio provided by the invention, and the yield and purity are lower than only one kind Examples of the catalyst reaction (Examples 6-9) were 80.4%, 93.5% (Comparative Example 5), 81.4%, and 94.0% (Comparative Example 6), respectively; the catalysts provided by the present invention were used in Examples 6-9, respectively. One of the preparation methods is the method provided by the present application, and the yield and purity of the antioxidant 1076 are still higher than the existing levels, the yield can be as high as 94%, and the purity is as high as 97.8%.

A pilot test of the antioxidant 1076 was carried out according to the method provided in Examples 2-9 of the present invention, and the yield of the finally obtained antioxidant 1076 was still above 90%, and the purity was as high as 99% or more, which was higher than the existing level, especially According to the pilot test conducted by the preparation method provided in Example 5, the yield of the antioxidant 1076 was over 92%, which provided a possibility for industrial mass production of antioxidants.

However, the above is only a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes made by the contents of the present invention and the description of the invention are Modifications are still within the scope of the claims of the present invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

Claims (10)

A method for synthesizing n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate, characterized in that the method comprises the following synthetic steps: (1) The reactant 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid methyl ester and solvent A were added to a three-necked flask, and then the rotor was placed, and the reflux condenser was fixed on a three-necked flask. , vacuum treatment under nitrogen protection, cycle 3 times; (2) The vacuum-treated three-necked flask containing the reactant obtained in the step (1) is placed in an ice bath for a certain period of time to obtain a reaction liquid; (3) adding catalyst A to the reaction liquid of the step (2), and after reacting for one hour, adding the reactant stearyl alcohol, removing the ice bath, and placing the three-necked flask containing the reaction liquid in an oil bath, at 80- After reacting at 100 ° C for 3 hours, it was cooled to 60 ° C, crystallized, and suction filtered to give a product. The preparation method according to claim 1, wherein the solvent A added in the step (1) is a mixed solution of ethylene glycol and toluene, and the volume ratio of ethylene glycol to toluene is 1-5:10- 200. The preparation method according to claim 1, wherein the reactant (3) is a methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate and the step (3) The ratio of the amount of the material of the reactant stearyl alcohol is from 1 to 1.2:1. The preparation method according to claim 1, wherein the reaction time in the ice bath condition in the step (2) is 10-30 min. The preparation method according to claim 1, wherein the catalyst A added in the step (3) is cerium carbonate, cerium carbonate, dibutyltin oxide, dibutyltin dilaurate, and tributyltin acetate. One or more of tetramethyl titanate, tetrabutyl titanate, isobutyl titanate, zirconium oxide and tetrabutyl zirconate; The preparation method according to claim 1, wherein the total amount of the catalyst A in the step (3) is 3-(3,5-di-tert-butyl-4-hydroxyphenyl group) by mass percentage. 0.25-0.3% of methyl propionate. The preparation method according to claim 1, characterized in that in the step (3), first, a total of half of the catalyst A of the catalyst A is added to the reaction liquid, and then the other half catalyst is added after the addition of the stearyl alcohol. A. The preparation method according to claim 1, wherein the step of synthesizing the methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate in the step (1) is : A. The reactant 2,6-di-tert-butylphenol and the catalyst B are added to a three-necked flask equipped with a N ₂ gas pipe, a rotor and a dropping funnel, and melted under nitrogen gas protection and heating to obtain a reactant; B. When the reaction temperature reaches 60-80 ° C, the reaction methyl ester is added dropwise to the reaction product of the step A. After the completion of the dropwise addition, the reaction is continued for 0.5 hour, and then the temperature is raised to 90-100 ° C to continue the reaction for 1 hour, followed by cooling. At 80 ° C, the reaction solution is adjusted to neutral with hydrochloric acid, crystallized, and filtered to obtain a product; The total amount of catalyst B used is, in mass percent, from 0.2 to 0.25% by weight based on the total mass of the reactant 2,6-di-tert-butylphenol and methyl acrylate. The preparation method according to claim 8, wherein the mass ratio of the reactant 2,6-di-tert-butylphenol in the step A to the methyl acrylate in the step B is 5:2. The preparation method according to claim 8, wherein the catalyst B added in the step B is zinc isooctanoate, zinc carbonate, zinc acetate, dibutyltin dilaurate, tributyltin acetate, stannous octoate. And one or more of dibutyltin diacetate.