CN115304638B - Synthesis method of 4,4' -butylene bis- (3-methyl-6-tertiary butylbenzene) -tetra (tridecyl) diphosphite - Google Patents

Abstract

The invention relates to a method for synthesizing 4,4' -butylene bis- (3-methyl-6-tertiary butylbenzene) -tetra (tridecyl) diphosphite. The method adopts a eutectic solvent [ ChCl ] [ TsOH ] or [ ChCl ] [ MA ] as a solvent and a catalyst, and prepares an intermediate 4,4 '-butylene bis (3-methyl-6-tertiary butyl phenol) by a microwave synthesis method, and synthesizes 4,4' -butylene bis- (3-methyl-6-tertiary butyl phenyl) -tetra (tridecyl) diphosphite from the intermediate. The method provided by the invention has the advantages of high intermediate yield and high product purity, so that the quality of the final product is good. The synthesis method is environment-friendly, and the eutectic solvent can be recycled and is suitable for industrial application.

Description

4,4’-Butylenebis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite Acid ester synthesis method

Technical field

The invention relates to the field of chemical industry. Specifically, the invention relates to the synthesis of 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite. method.

Background technique

Phosphite antioxidants refer to structures with the formula (R ₁ and R ₃ are alkyl, aryl, substituted aryl, which can be the same or different, and can also form a ring). It is an auxiliary antioxidant and acts as a hydroperoxide. Decomposers and free radical scavengers play an antioxidant role in polymers, and are often used together with hindered phenols, and are generally not used alone. Phosphite antioxidants include: triphenyl phosphite, trinonyl phosphite, monobutyl diphenyl phosphite, tris(nonylphenol) phosphite, tris(2,4-di-tert-butyl phosphite) )Phenyl phosphite, trioctyl phosphite, bis(2-methyl-4,6-di(1,3-dimethylethyl)phenyl)ethyl phosphite, dioctadecylpentaerythritol bis Phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, 4,4' -Butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite, etc.

Among them, 4,4’-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite has excellent properties and strong market demand. It is usually prepared by the following method: 3-methyl-6-tert-butylphenol and n-butyraldehyde are synthesized in the presence of a base and a catalyst to synthesize the intermediate 4,4'-butylene bis(3-methyl-6-tert-butyl Phenol), which is obtained by reacting with triphenyl phosphite and tridecyl alcohol in the presence of a base, and low-boiling impurities and phenol are removed by distillation. Among them, the purity of the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol) is related to 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl) -Quality of tetrakis(tridecyl)diphosphite. The intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol) (BBM) itself is also an antioxidant, disclosed in US2970151, US28318974, US2822404, JP2007269711A, JP2012136548A, CN108586206A, CN104591972A, etc. Hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, etc. are used as catalysts, but there are problems such as low product yield and purity, troublesome post-processing, and a lot of three wastes.

Therefore, there is a need to develop more methods that can effectively synthesize 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite.

Contents of the invention

In view of the above problems existing in the prior art, the present invention provides a kind of 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite. The preparation method uses 3-methyl-6-tert-butylphenol and n-butyraldehyde as raw materials, uses a deep eutectic solvent containing p-toluenesulfonic acid or malonic acid as both a solvent and a catalyst, and synthesizes intermediate 4 under microwave radiation. ,4'-butylene bis(3-methyl-6-tert-butylphenol), and then synthesize 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(deca) Trialkyl) diphosphite.

A deep eutectic solvent (DES) is a eutectic mixture with a melting point lower than 100°C formed by a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) through intermolecular hydrogen bonds. HBA includes quaternary ammonium salts, quaternary phosphonium salts, etc., and HBD includes amides, alcohols, carboxylic acids, sulfonic acids, etc. DES can be used both as an extraction agent and as a solvent in organic reactions, and can also be used as a catalyst when HBD or HBA contains special functional groups. DES has the advantages of simple preparation, cheap raw materials, and reusability.

The invention provides a synthesis method of 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite, which includes:

Step 1: Add 3-methyl-6-tert-butylphenol, organic base and n-butylphenol to a deep eutectic solvent composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) or malonic acid (MA). Butyraldehyde, react under microwave radiation at 40-70°C; then add an organic solvent for extraction, the extract is washed, dried, and desolvated, and the residue is recrystallized to obtain the intermediate 4,4'-butylene bis(3-methyl) -6-tert-butylphenol);

Step 2: React the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol) with triphenyl phosphite and tridecanol in the presence of a base to obtain 4,4'- Butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite.

In a preferred embodiment, the deep eutectic solvent composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) or malonic acid (MA) includes chlorine with a molar ratio of 1:1 The deep eutectic solvent [ChCl][TsOH] composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH), and the molar ratio of choline chloride (ChCl) and malonic acid (MA) are 1:1. The deep eutectic solvent consists of [ChCl][MA].

The deep eutectic solvent can be prepared by the following method:

Under the protection of inert gas, heat the mixture of choline chloride and p-toluenesulfonic acid or malonic acid to 90-120°C and stir until the solution is completely transparent.

Preferably, the molar ratio of choline chloride to p-toluenesulfonic acid or malonic acid is 1:1.

Preferably, the stirring temperature is 100-110°C.

In the present invention, the amount of the deep eutectic solvent is such that the ratio of the molar amount of p-toluenesulfonic acid or malonic acid to the molar amount of 3-methyl-6-tert-butylphenol is 0.5 to 1.5:1. , preferably 0.8 to 1.2:1.

In a preferred embodiment, the organic base is selected from at least one of triethylamine, pyridine, and tetramethylethylenediamine, and is preferably tetramethylethylenediamine. The amount of organic base used is 0.5 to 5% of the mass of 3-methyl-6-tert-butylphenol, preferably 1 to 2.5%.

In a preferred embodiment, the molar ratio of 3-methyl-6-tert-butylphenol to n-butyraldehyde is 2 to 2.2:1, preferably 2 to 2.1:1.

In a preferred embodiment, the microwave power is 200-600W, preferably 300-400W.

In a preferred embodiment, the reaction temperature is 55-65°C; the reaction time is 1-30 min, preferably 10-15 min.

In a preferred embodiment, the organic solvent is selected from at least one of diethyl ether, methyl tert-butyl ether, and ethyl acetate; preferably, it is selected from methyl tert-butyl ether.

In a preferred embodiment, the washing includes washing with saturated aqueous sodium bicarbonate solution and water 1 to 3 times respectively.

In a preferred embodiment, the recrystallization includes heating and dissolving the desolvated residue in 1.5 to 2.5 times the mass of methanol, and then back-dropping 0.4 to 0.6 times the mass of methanol in water, and then naturally lowering it to room temperature. Crystals precipitate.

Preferably, the heating includes heating to a boiling state; the amount of methanol is preferably 1.8 to 2.2 times the mass of the residue; the amount of water is preferably 0.45 to 0.55 times the mass of methanol.

In the present invention, step 2 includes:

Under the protection of inert gas, add the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol), tridecanol, and triphenyl phosphite into the reactor, and heat with stirring until 45～60℃, make the mixture form a turbid solution, then add the inorganic base, and then heat the reaction mixture to 140～170℃ for 1.5h; remove the low boiling matter and phenol by vacuum distillation, and reduce the remaining mixture to 50～60℃ and filtered to obtain 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite.

In a preferred embodiment, the molar ratio of the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol), tridecanol, and triphenyl phosphite is: 1:4 ~5:2~2.5, preferably 1:4~4.2:2~2.1.

In a preferred embodiment, the inorganic base is selected from at least one of sodium hydroxide, potassium hydroxide, and cesium carbonate. The amount of inorganic base used is 0.1 to 1% of the mass of 4,4'-butylene bis(3-methyl-6-tert-butylphenol).

The deep eutectic solvent has the advantages of being renewable and recyclable. After regeneration, it can continue to be used in the synthesis process of the intermediate 4,4’-butylene bis(3-methyl-6-tert-butylphenol). Therefore, the method of the present invention may also include the step of regenerating the deep eutectic solvent, and further, may further include the step of reusing the regenerated deep eutectic solvent.

In a preferred embodiment, the regeneration step of the deep eutectic solvent: collects the used deep eutectic solvent and washes it with at least one organic solvent selected from diethyl ether, methyl tert-butyl ether, and ethyl acetate, It can be obtained by drying at 80~120℃.

In a preferred embodiment, regenerated deep eutectic solvent can be used in step 1. When the deep eutectic solvent is recycled, it can still maintain good catalytic properties even if it is recycled six times.

In the present invention, the inert gas includes at least one of nitrogen or argon.

beneficial effects

The invention provides a synthesis method of 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite. In the method of the present invention, in the synthesis process of the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol), a deep eutectic solvent [ChCl][TsOH] or [ChCl][MA is used ] simultaneously serves as a solvent and catalyst to prepare the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol) through microwave synthesis. The reaction yield is high and the product purity can reach more than 99.5%. . In the present invention, when a deep eutectic solvent is used, microwave assistance not only greatly increases the reaction rate, but also significantly improves the reaction yield. The deep eutectic solvent of the present invention can be recycled multiple times, and the purity of the product can still reach more than 99.0% after 6 cycles, and the synthesis method is green and environmentally friendly. 4,4'-butylene bis-(3-methyl-6- Tert-butylphenyl)-tetrakis (tridecyl) diphosphite product, with high content and good quality. Therefore, the method of the present invention is suitable for industrial application.

Detailed ways

The technical solutions of the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

Preferred examples of the invention will be described in detail below. The examples are given to better understand the content of the invention, and the content of the invention is not limited to the examples. Non-essential improvements and adjustments to the embodiments based on the content of the invention still fall within the scope of the invention.

The experimental methods in the following examples are all conventional methods unless otherwise specified. If specific techniques or conditions are not specified in the examples, the techniques or conditions described in literature in the field shall be followed, or the product instructions shall be followed.

Example 1:

Under nitrogen protection, add a mixture of 0.2 mol of choline chloride (ChCl) and 0.2 mol of p-toluenesulfonic acid (TsOH) into the reactor of the magnetic device, heat to 100°C and stir for 1 hour until the solution is completely transparent. The alkali absorbs the small amount of HCl released; slowly cooling to room temperature, the deep eutectic solvent [ChCl][TsOH] is obtained. Add 0.2 mol of 3-methyl-6-tert-butylphenol and 0.5 g of tetramethylethylenediamine, slowly add 0.1 mol of n-butyraldehyde dropwise, and react at 60°C for 10 minutes under 300W microwave radiation. After cooling, slowly add 300 ml of methyl tert-butyl ether to extract the product. Carefully separate the methyl tert-butyl ether layer and wash it twice with saturated sodium bicarbonate aqueous solution and water respectively, dry over anhydrous sodium sulfate, and obtain 37.1g after desolvation. The residue was put into 60g of methanol, heated to boiling and dissolved, then the heating was stopped and 30g of water was slowly added dropwise, and then naturally cooled to room temperature to precipitate crystals to obtain the crystalline intermediate 4,4'-ydenine. Bis(3-methyl-6-tert-butylphenol) 34.9g, yield 91.22%, purity 99.73%. ESI-MS: 383.3[M+H] ⁺ .

Under nitrogen protection, 50 mmol of the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol), 210 mmol of tridecanol and 100 mmol of triphenyl phosphite were added to the reactor. , heated to 55°C with stirring to make the mixture form a turbid solution, then add 0.1g of KOH, and then heat the reaction mixture to 150°C for 1.5h; then, stop supplying nitrogen and perform vacuum distillation with a pressure of 1 mmHg. The temperature is 180-185°C until all the low boilers and phenol are evaporated. The remaining mixture was lowered to 55°C and filtered to obtain colorless and transparent 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite. 61.8g, content 98.41%. ESI-MS: 1240.1[M+H] ⁺ .

Example 2: Reuse of deep eutectic solvent [ChCl][TsOH]

The deep eutectic solvent [ChCl][TsOH] extracted with methyl tert-butyl ether in Example 1 was washed 1-2 times with methyl tert-butyl ether, and then heated to 95°C and dried for 1 hour. After cooling, the subsequent reaction and treatment steps were carried out in a similar manner to Example 1. Repeat this step several times. The conditions for obtaining the intermediate 4,4’-butylene bis(3-methyl-6-tert-butylphenol) are listed in the following table:

repeat times 1 2 3 4 5 6 Yield 90.83% 90.54% 90.11% 89.43% 88.34% 85.25% purity 99.63% 99.61% 99.53% 99.40% 99.22% 99.04%

Example 3:

Under nitrogen protection, add a mixture of 0.2 mol of choline chloride (ChCl) and 0.2 mol of p-toluenesulfonic acid (TsOH) into the reactor of the magnetic device, heat to 100°C and stir for 1 hour until the solution is completely transparent. The alkali absorbs the small amount of HCl released; slowly cooling to room temperature, the deep eutectic solvent [ChCl][TsOH] is obtained. Add 0.25 mol of 3-methyl-6-tert-butylphenol and 0.625 g of tetramethylethylenediamine, slowly add 0.125 mol of n-butyraldehyde dropwise, and react at 60°C for 10 minutes under 300W microwave radiation. After cooling, slowly add 370 ml of methyl tert-butyl ether to extract the product. Carefully separate the methyl tert-butyl ether layer and wash it twice with saturated sodium bicarbonate aqueous solution and water respectively, dry over anhydrous sodium sulfate, and obtain 45.2g after desolvation. The residue was put into 75g of methanol, heated to boiling and dissolved, then the heating was stopped and 37.5g of water was slowly added dropwise, and then naturally cooled to room temperature to precipitate crystals to obtain crystalline intermediate 4,4'- Butylene bis(3-methyl-6-tert-butylphenol) 42.8g, yield 89.49%, purity 99.5%.

Example 4:

Under nitrogen protection, add a mixture of 0.2 mol choline chloride (ChCl) and 0.2 mol malonic acid (MA) into the reactor of the magnetic device, heat to 100°C and stir for 1.5 hours until the solution is completely transparent. The lye absorbs the small amount of HCl released; slowly cooling to room temperature, the deep eutectic solvent [ChCl][MA] is obtained. Add 0.2 mol of 3-methyl-6-tert-butylphenol and 0.5 g of tetramethylethylenediamine, slowly add 0.1 mol of n-butyraldehyde dropwise, and react at 60°C for 10 minutes under 300W microwave radiation. After cooling, slowly add 330 ml of methyl tert-butyl ether to extract the product. Carefully separate the methyl tert-butyl ether layer and wash it twice with saturated sodium bicarbonate aqueous solution and water respectively, dry over anhydrous sodium sulfate, and obtain 37.8g after desolvation. The residue was put into 60g of methanol, heated to boiling and dissolved, then the heating was stopped and 30g of water was slowly added dropwise, and then naturally cooled to room temperature to precipitate crystals to obtain the crystalline intermediate 4,4'-ydenine. 35.4g of bis(3-methyl-6-tert-butylphenol), yield 92.52%, purity 99.6%.

Example 5: Reuse of Deep Eutectic Solvent [ChCl][MA]

The deep eutectic solvent [ChCl][MA] extracted with methyl tert-butyl ether in Example 2 was washed 1-2 times with methyl tert-butyl ether, and then heated to 95°C and dried for 1 hour. After cooling, the subsequent reaction and treatment steps were carried out in a similar manner to Example 4. Repeat this step several times. The conditions for obtaining the intermediate 4,4’-butylene bis(3-methyl-6-tert-butylphenol) are listed in the following table:

repeat times 1 2 3 4 5 6 Yield 91.73% 91.50% 91.02% 90.54% 89.86% 86.45% purity 99.63% 99.70% 99.45% 99.31% 99.15% 99.10%

Comparative example 1:

Under nitrogen protection, add a mixture of 0.2 mol of choline chloride (ChCl) and 0.2 mol of p-toluenesulfonic acid (TsOH) into the reactor of the magnetic device, heat to 100°C and stir for 1 hour until the solution is completely transparent. The alkali absorbs the small amount of HCl released; slowly cooling to room temperature, the deep eutectic solvent [ChCl][TsOH] is obtained. Add 0.2 mol of 3-methyl-6-tert-butylphenol and 0.5 g of tetramethylethylenediamine, slowly add 0.1 mol of n-butyraldehyde dropwise, and heat in an oil bath to 60°C for 3 hours. After cooling, slowly add 300 ml of methyl tert-butyl ether to extract the product. Carefully separate the methyl tert-butyl ether layer and wash it twice with saturated sodium bicarbonate aqueous solution and water respectively, dry over anhydrous sodium sulfate, and obtain 36.2g after desolvation. The residue was put into 60g of methanol, heated to boiling and dissolved, then the heating was stopped and 30g of water was slowly added dropwise, and then naturally cooled to room temperature to precipitate crystals to obtain the crystalline intermediate 4,4'-ydenine. 32.3g of bis(3-methyl-6-tert-butylphenol), yield 84.42%, purity 98.76%.

The preferred embodiments of the present invention have been described above, but they are not intended to limit the present invention. Those skilled in the art may make modifications and changes to the embodiments disclosed herein without departing from the scope and spirit of the invention.

Claims (9)

1. A method for synthesizing 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite, comprising: Step 1: Add 3-methyl-6-tert-butylphenol, organic base and n-butylphenol to a deep eutectic solvent composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) or malonic acid (MA). Butyraldehyde, react under microwave radiation at 40-70°C; then add an organic solvent for extraction, the extract is washed, dried, and desolvated, and the residue is recrystallized to obtain the intermediate 4,4'-butylene bis(3-methyl) -6-tert-butylphenol); the microwave radiation, the microwave power is 200~600W; the described microwave radiation is composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) or malonic acid (MA) The deep eutectic solvents are respectively the deep eutectic solvent [ChCl][TsOH] composed of choline chloride (ChCl) and p-toluenesulfonic acid (TsOH) with a molar ratio of 1:1, and the deep eutectic solvent [ChCl][TsOH] composed of a molar ratio of 1:1 A deep eutectic solvent [ChCl][MA] composed of choline chloride (ChCl) and malonic acid (MA); the organic base is selected from tetramethylethylenediamine; the organic solvent is selected from ether, methane At least one of tert-butyl ether and ethyl acetate; the recrystallization includes heating and dissolving the desolvated residue in 1.5 to 2.5 times the mass of methanol, and then back-dropping 0.4 to 0.6 times the mass of methanol. Water, naturally cooled to room temperature to precipitate crystals; Step 2: React the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol) with triphenyl phosphite and tridecanol in the presence of inorganic base to obtain 4,4' -Butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis(tridecyl)diphosphite. 2. The synthetic method according to claim 1, characterized in that the deep eutectic solvent is prepared by the following method: Under the protection of inert gas, heat the mixture of choline chloride and p-toluenesulfonic acid or malonic acid to 90-120°C and stir until the solution is completely transparent. 3. The synthetic method according to claim 1, characterized in that the consumption of the deep eutectic solvent is such that the molar amount of p-toluenesulfonic acid or malonic acid is equal to that of 3-methyl-6-tert-butyl. The molar ratio of phenol is 0.5 to 1.5:1. 4. The synthetic method according to claim 1, wherein the amount of the deep eutectic solvent is such that the molar amount of p-toluenesulfonic acid or malonic acid is equal to that of 3-methyl-6-tert-butyl. The molar ratio of phenol is 0.8-1.2:1. 5. The synthesis method according to claim 1, characterized in that the amount of organic base is 0.5 to 5% of the mass of 3-methyl-6-tert-butylphenol. 6. The synthesis method according to claim 1, characterized in that the organic solvent is selected from methyl tert-butyl ether. 7. The synthesis method according to claim 1, characterized in that said step 2 includes: Under the protection of inert gas, add the intermediate 4,4'-butylene bis(3-methyl-6-tert-butylphenol), tridecanol, and triphenyl phosphite into the reactor, and heat with stirring until 45～60℃, make the mixture form a turbid solution, then add the inorganic base, and then heat the reaction mixture to 140～170℃ for 1.5h; remove the low boiling matter and phenol by vacuum distillation, and reduce the remaining mixture to 50～60℃ and filtered to obtain 4,4'-butylene bis-(3-methyl-6-tert-butylphenyl)-tetrakis (tridecyl) diphosphite. 8. The synthesis method according to claim 1, characterized in that the method further includes the step of regenerating the deep eutectic solvent, and the step of reusing the regenerated deep eutectic solvent. 9. The synthesis method according to claim 8, characterized in that the regeneration step of the deep eutectic solvent: collects the used deep eutectic solvent and uses it with a solvent selected from the group consisting of diethyl ether, methyl tert-butyl ether, and ethyl acetate. It can be obtained by washing with at least one organic solvent and drying at 80~120℃.