SU1685919A1 - Method for obtaining methyl ester of @@@-(4-hydroxy-3,5-di-tret-(butylphenyl)propionic acid - Google Patents

Abstract

The invention relates to esters of acids, in particular the preparation of methyl ester of (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid, used in polymeric chemistry and agriculture. The goal is to intensify and simplify the process while improving the quality of the target product. The synthesis is carried out by the reaction of 2,6-di-tert-butylphenol with methyl acrylate (molar ratio 1: 1-1.15) at 90-150 ps in the presence of a catalyst. The composition of the latter includes, in wt%: 4-methylcarboxyethyl) -2,6-di-tert-butylphenol sodium 57.2-3.2, 2.6-di-tert-butyl phenyl potassium 5.6-0.2 and 2,6-di-tert-butylphenol - up to 10. Moreover, the components of alkali metals are used in the amount of 1.5-10 mol.% from 2,6-di-tert-butylphenol in terms of the amount of alkali salts. These conditions reduce the process time by almost 3 times due to obtaining a high yield of the target product 96% in 15 minutes versus 35% in 15 minutes) with a high content of the basic substance.

Description

The invention relates to organic chemistry, specifically to a method for producing methyl ester of / - {4-hydroxy-3.5-di-tert-butylphenyl) propionic acid, which is used in the polymer industry and agriculture.

The aim of the invention is to intensify and simplify the process while improving the quality of the target product.

The process is carried out by reacting 2,6-di-tert-butylphenol with methyl acrylate at a molar ratio of 1: 1-1.15, respectively, at a temperature of 90-150 ° C in the presence of a catalyst containing, along with 2,6-di-tert potassium-butyl phenyl and 2,6-di-tert-butylphenol 4-0-methylcarboxyethyl) -2,6-di-tert-butyl phenol t sodium in the following ratio of these components, wt.%: 2,6- Potassium di-tert-butylphenol t 57.2-3.2

4- -methylcarboxyethyl) - 2,6-di-tert-butylphenol sodium 5,6-0,2

2.6-Di-tert-butylphenol Else The indicated components of alkali metals are used in the amount of 1.5-10

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mol% of 2,6-di-tert-butylphenol based on the amount of 4-methylcarboxyethyl} -2,6-di-tert-butylphenol sodium and 2,6-di-tert-butylphenol potassium.

The desired product is isolated by one of the methods indicated in the examples, and (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is also obtained.

The catalyst is prepared either by mixing the individual sodium 2,6-di-tert-butyl phenol and 2,6-di-tert-butylphenol, or it is prepared by heating the sodium hydroxide and potassium hydroxide with 2,6-di- tert-butylphenol in a stream of inert gas at 100-150 ° C for 30-120 minutes with the separation of water and partially 2,6-di-tert-butylphenol and subsequent heating under the same conditions of the reaction mixture with methyl ether ft - (4 -hydroxy-3,5-di-tert-butylphenyl) propionic acid.

The composition of the catalyst and its activity do not depend on the method of its preparation, which follows from the reaction of 2,6-di-tert-butyl-phenol and sodium methyl ether 3 - (4-hydroxy-3,5-di-tert-butylphenyl ) propionic acid, as a result of which 2,6-di-tert-butylphenol, 2,6-di-tert-butylphenol potassium is regenerated with methyl ether ft - {4-hydroxy-3,5-di-tert-butylfe- nyl) propionic acid does not react and, therefore, when a mixture of sodium hydroxide and potassium hydroxide is heated with 2,6-di-tert-butylphenol with a conversion of up to 99.9%, a catalyst is formed - 2,6-di- Sodium t-butylphenol and potassium 2,6-di-t-butylphenol. When these phenols are treated with methyl (4-hydroxy-3,5-di-tert-butylphenyl) -propionic acid methyl ester, a catalyst consisting of 4-5-methyl l carboxyethyl-, 2,6-di-tert-butylphenol t sodium, 2,6-di-tert-butylphenol potassium, and 2,6-di tert-butylphenol.

The calculated amount of 2,6-di-tert-butylphenol and methylate is added to the catalyst prepared by this method. The reaction with a high speed takes place in the range of 90-150 ° C, but it is advisable to carry out the process at 120-130 °, especially when carrying out the process in a continuous mode.

The methyl ester of / - {4-hydroxy-3,5-D1-g-tert-butylphenyl) propionic acid can be isolated by treating the reaction mass with water, cooling the reaction mixture to 20-10 ° C, filtering and washing with a hydrocarbon fraction or by treating the reaction mass with aqueous isopropyl alcohol, cooling to 5-10 ° C and filtering or distilling off unreacted 2,6-di-tert-butylphenol to obtain the desired product as a melt. From the aqueous or aqueous-alcoholic fraction, treatment with carbon dioxide additionally yields ft - {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid.

The invention is illustrated by the following examples.

Example 1. In a steel autoclave

with a capacity of 100 ml, 41.3 (0.2 g mol) of 2,6-di-tert-butylphenol, 1.4 g (0.0045 g mol) of 4-methylcarboxyethyl) -2,6-di-tert-butyl phenol and sodium. 0.37 g (0.0015 g mol) 2,6-di-tert-butylphenol potassium and get in

the result of mixing is 43.07 g of catalyst, whose composition and content of its alkaline components are given in the table. The content of the catalyst components corresponds to the amount of the same components. taken before mixing, which is confirmed by analysis. Next, 41.3 g of 2,6-di-tert-butylphenol, 1.4 g4- (0-methylcarboxyethyl) -2, b-di-tert-butylpheno are placed in a steel autoclave at room temperature.

sodium and 0.37 g of 2,6-di-tert-butylphenol potassium; 18 ml (0.2 g mol) of methyl acrylate are added and the autoclave is placed in a thermostat with silicone liquid heated to 150 ° C and incubated at this temperature for 15 minutes. The heating time of the autoclave from room temperature to 150 ° C is 3.0-3.5 minutes and during this time the reaction proceeds by 35-40% (according to an analysis on a liquid chromatograph. Liquid

Vgikeg chromatograph 1 C-31, IBM Suapo column, eluent: hexane-isopropyl alcohol (9: 1), working pressure 28 atm, speed 0.4 ml / min).

After 15 min, the autoclave is removed from

thermostat, cooled to 70-80 ° C, the light colored reaction mass is poured into a beaker with 20 ml of water and cooled to 20 ° C (room temperature). A crystalline mass is formed in the beaker, which is filtered. The filter cake was washed with 20 ml of hexane cooled to 10 ° C and, after drying in air, 46.7 g (80%) of methyl ester of / - {4-hydroxy-3,5-di-tert-butylphenyl) propionic ether were obtained.

acids with the content of the main substance of 99.8% (according to LC), so pl. 77-68 ° C. From the hexane solution, 9.3 g (16%) of the desired product are additionally obtained by fractionation, mp. 67-68 ° C.

Data on the composition of the catalyst, the selectivity of the process and the conversion of 2,6-di-tert-butylphenol are presented in the table.

Example 2. In a steel autoclave, 41.3 g (0.2 g mol) of 2,6-di-tert-butylphenol, 0.28 g (in terms of 100%) (0.007 g mol) of sodium hydroxide, 0.0224, are placed. g (0.0004 g mol) of potassium hydroxide, nitrogen is passed, heated to 135-140 ° C and kept in a stream of nitrogen for 50 minutes and 15 g of 2,6-di-tert-butylphenol are collected in the receiver. 2.05 g (0.007 g mol) of methyl ether are added to the reaction mixture.

/ H4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and 15 g of 2,6-di-tert-butylphenol, cooled to 70 ° C and get a catalyst in the amount of 43.5 g, the composition the content of its alkaline components from 2,6-di-tert-butylphenol is given in the table. From 43.5 g of the catalyst, as a result of the analysis according to the procedure described in Example 1, 2.22 g (0.007 g mol) of 4-methyl carboxyethyl) -2,6-di-tert-butyl phenol and sodium, 0, are obtained. 09 g (0.0004 g mol) 2,6-di-tert-butylphenol potassium, 2,6-di-tert-butylphenol - the rest.

Next, to the catalyst heated in an autoclave in a stream of nitrogen in the amount of 43.5 g of this composition was added 19 ml (0.21 gx hmol) of methyl acrylate, the autoclave was placed in a thermostat with silicone oil at 100 ° C and kept for 60 minutes at 90-100 ° WITH. The heating time of the autoclave is from 70 ° C to 100 ° C for 1.5-2.0 minutes and during this time the reaction proceeds by 15-20% (according to an analysis on a liquid chromatograph). After 60 min, the autoclave is removed from the thermostat, cooled to 70 ° C, the reaction mass is poured into glasses with 40 ml of aqueous isopropyl alcohol, the solution is cooled to 8-10 ° C and filtered after 1.5 h. The yield of methyl ether / 7- {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is 58.8 g (92%), so pl. 67-68 ° C.

1.9 g of (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid, m.p. 175 ° C.

Example 3. In a steel autoclave, 20.6 (0.1 g mol) of 2,6-di-tert-butylphenol, 0.11 g (0.00275 g mol) of sodium oxide hydrate and 0.02 g (0.00035 g mol ) potassium hydroxide, argon is passed through, heated to 150 ° C and 2,6-di-tert-butylphenol is distilled off in a stream of argon, 0.81 g (0.00275 g mole) of methyl ester (4-hydroxy-3 , 5-di-tert-butylphenyl) propionic acid and get 1.58 g of catalyst, the composition of which and the content of its alkaline components from 2,6-di-tert-butylphenol are given in the table.

From 1.58 g of the catalyst as a result of analysis by the method described in example 1,

0.9 g is obtained, - i, fv.,; n, V, di-tert-butylphenol and sodium. O.Ya6 F 2 6 di-tert-butylphenop was tapped,

2,6-di-tert-butylphenol - the rest. 5K 1.58 catalysts of the specified composition

41.2 g of 2,6-di-tert-butylphenol and 18 ml of methyl acrylate are added. The mixture is placed in an autoclave filled with argon, which is then placed in a thermostat with silicone

10 with oil at 120 ° С and kept at this temperature for 90 min. The heating time of the autoclave from room temperature to 120 ° C is 2.5-3.0 minutes and during this time the reaction proceeds by 10-15%. 90 minutes after the start of heating, the autoclave is removed from the thermostat, the reaction mass is cooled to 80 ° C and poured into a beaker with 25 ml of water, the mixture is cooled to 10 ° C. In glass

0, a crystalline mass is formed, which is filtered, and then the target product is isolated according to example 1. Yield 58.8 g (92%), mp. 67-68 ° C.

Example 4 (pilot production) Into a 1 m reactor equipped with a stirrer, a heat exchanger and a gas inlet that forms a single system that circulates the gas flow and consists

0 from the heat exchanger, water collecting tank and 2,6-di-tert-butylphenol, blower compressor and zeolite column to absorb residual water, 412.6 kg (2 kg mol) 2.6-di-ter5 butylphenol are placed, 4 kg (in terms of 100%) (0.1 kg mol) of sodium hydroxide, 1.4 kg (in terms of 100%) (0.025 kg mol) of potassium hydroxide. Nitrogen was passed into the reactor at a rate of 80 l / min, heated to 1,300– 135 ° C, and water and 80 kg of 2,6-di-tert-butylphenol were distilled off for 3 hours. The reaction mass is cooled to 40 ° C, 29.2 kg (0.1 kg mol) of methyl methyl ethyl ether (- (4-hydroxy-3,5-di-tert-butylphenyl) propionic) are added.

5 acids and 80 kg of 2,6-di-tert-butylphenol. mix for 10 minutes and take a sample for analysis of the catalyst composition in the amount of 50 ml. Next, from the measuring device under the pressure of nitrogen, 180 liters (2 kg mol) of methyl acrylate are added. The temperature is raised so that the temperature of the reaction mass does not exceed 140-145 ° C. After the addition of methyl acrylate, the reaction mass is kept for 30-40 min. At the same time, the temperature of the reaction mass rises from 40 to 120 ° C. According to the analysis, after 37 minutes, the content of methyl ester of 9- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is 96.4 mol. %, 2,6-di-tert-butylphenol 3.1 mol.%.

Next, the reaction mass is cooled to 70 ° C and treated as in example 2. The yield of methyl ester / - {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is 555 kg (95%), so pl. 67-68 ° C.

Analysis of the composition of the catalyst is carried out according to Example 1. Out of 50 g of catalyst, 3.55 g of 4-methylcarboxyethyl} - 2,6-di-tert-butylphenol sodium, 0.7 g 2,6-di potassium tert-butylphenol and 2,6-tert-butylphenol, the rest.

Example 5: 1 g (0.00438 g mol) of 2,6-di-tert-butylphenol sodium, 0.12 g (0.0005 g mol) of 2,6-di-tert-butylphenol potassium are placed in a glass vial. and 1.28 g (0.00438 g mol) of (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid methyl ester. The mixture in a stream of argon is heated for 15 minutes at 80 ° C, cooled, and a 2.4 g catalyst is obtained, the composition of which is given in the table. From 2.4 g of the catalyst, as a result of the analysis according to the procedure described in Example 1, 1.373 g of 4- (Tmethylcarboxyethyl) -2,6-di-tert-butyl-phenol sodium, 0.12 g of 2,6-di potassium t-butylphenol and 9.07 g of 2,6-di-t-butylphenol.

To 2.4 g of the catalyst were added 9.1 g (0.044 g mol) of 2,6-di-tert-butylphenol and 5 ml (0.0554 g / mol) of methyl acrylate. The mixture is flushed with argon, the ampule is sealed and placed in a thermostat with silicone oil heated to 120 ° C, and incubated for 10 minutes. Ampoule heating time 1 min. After crystallization from aqueous isopropyl alcohol, the yield of the desired product is 14 g (99%), so pl. 67-68 ° C.

Example 6. From a container containing 206 g (1 g mol) of 2,6-di-tert-butylphenol, 11.63 g (0.037 g mol) of 4 - (/) - methylcarboxyethyl) -2,6-di- sodium tert-butylphenol and 0.733 g (0.003 g mol) 2,6-di-tert-butylphenol potassium, and another vessel containing methyl acrylate, in a tubular reactor having a length of 15 cm and a diameter of 1 cm, the catalyst and methyl acrylate are fed at the molar ratio of 2,6-di-tert-butylphenol: methyl acrylate is 1: 1. The temperature of the reactor is 145 ° C. The reaction mixture was pressurized with nitrogen at a rate of 1 ml / min. When leaving the reactor, the conversion of 2,6-di-treg-butylphenol is 96.5%, the selectivity is 99.5% (according to LC). To analyze the composition of the catalyst, only the catalytic mixture is fed to the reactor at a speed of 3-4 ml / min, 20 g of catalysate is taken, and the analysis according to Example 1 is carried out. From 1 g of catalyst, 1.06 g of 4 - o) - 2,6-di-tert-butylphenol sodium, 0.06 g of 2,6-di-tert-butylphenol potassium and 2,6-di-tert-butylphenol - the rest. Example 7. A catalyst is prepared by mixing 1.377 g (0.00668 gx

hmol) 2,6-di-tert-butylphenol, 1.878 g (0.00598 g mol) 4- -methylcarboxyethyl) - 2,6-di-tert-butylphenol sodium, 0.0051 g (0.00002 g mol) 2,6-di-tert-butylphenol potassium and get 3,2601 g of catalyst, the composition of which is given in the table. From 3.2601 g of the catalyst, as a result of the analysis according to the procedure described in Example 1, 1.8778 g of 4-methylcarboxyethyl) -2,6-di-tert-butylphenol sodium, 0.0049, 2,6-dihydrate potassium butylphenol and 2,6-di-tert-butylphenol - the rest.

The catalyst in the amount of 3.2601 g is placed in an autoclave, 39.823 823 g (0.19332 g mol) of 2,6-di-tert-butylphenol and

18 ml of methyl acrylate. The mixture was flushed with argon, the autoclave was placed in a thermostat with a silicone liquid heated to 150 ° C, and kept at this temperature for 15 minutes. After processing the reaction

the mixtures of Example 1 are 51.14 (88% of the theoretical) of the desired product, m.p. 66.5-67.0 ° C.

Example 8 A catalyst is prepared by mixing 18.6 g (0.009 g mol)

2,6-di-tert-butylphenol, 0.5 g (0.00159 g-mol) 4-5-methylcarboxyethyl) -2,6-di-tert-butyl fsnol sodium, 1.2 g (0.00492 g mol) 2,6-di-tert-butylphenol potassium and get 20.3 g of the catalyst, the composition of which is given in the table. From 20.3 g of the catalyst, as a result of the analysis according to the procedure described in Example 1, 0.50 g of 4 - (- methylcarboxyethyl) -2,6-di-tert-butylphenol sodium and 1.198 g of 2,6-di tert-butylphenol ta

potassium, 2,6-di-tert-butylphenol - the rest, the catalyst of the specified composition in the amount of 20.3 is placed in an autoclave, 22.7 g (0.11 g mol) of 2,6-di-tert-butylphenol and 18 ml (0.2 g mol) of methyl acrylate. The mixture is flushed with argon and the autoclave is placed in a thermostat with silicone liquid at 150 ° C. The reaction and treatment of the reaction mixture is carried out as in Example 1. 45.3 g (78% of the theoretical) are obtained, m.p. 66-67 ° C.

Example 9 (comparative and). In a flask equipped with a reflux condenser, a receiver for water extraction and an inert gas inlet are heated in the atmosphere

nitrogen 42 g (0.2 g mol) of 2,6-di-tert-butylphenol with 7 g (0.125 g mol) of potassium hydroxide in 250 ml of xylene and at a boiling point (88-140 ° C) are taken into the receiver 2 ml water, the xylene is distilled off the precipitate is filtered

and heated for 10 minutes at 150 ° C. Get the catalyst of the following composition, wt.: Potassium oxide hydroxide 0.5

2,6-di-tert-butylphenol potassium 99 2,6-di-tert-butylphenol 0.5

41.3 g (% 62 gx hmol) 2, b-di-tert-butylphenol, 1.72 g of a catalyst of the specified composition and 18 ml (0.2 g mol) of methyl acrylate are placed in an autoclave. The autoclave is placed in a thermostat with a silicone liquid heated to 150 ° C and kept at this temperature for 15 minutes. After 15 min, the autoclave is removed from the thermostat, further processing and extraction of the target product is carried out as in Example 1, 18.7 g (32% of the theoretical) of the desired product are obtained, mp. 64-65 ° C.

Used in the proposed method, the catalyst is characterized by high activity and selectivity, which allows to reduce the process time to 10-60 minutes instead of 210 minutes, to simplify the selection of the target product, partially or completely eliminating the energy-intensive stage of fractionation in vacuum and improve the quality of the target product and additionally obtain / - {4-hydroxy-3,5-di-tert-butylphenyl) -propionic acid.

Claims (1)

Formula and s k. and rep with n and h The method of producing (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid methyl ester by reacting 2,6-di-tert-butylphenol with methyl acrylate at a molar ratio of 1: 1-1.15, increased temperature in the presence of a catalyst containing 1,6-di-tert-butylphenol potassium t and 2,6-di-tert-butylphenol at 90-150 ° C, characterized in that, in order to intensify and simplify the process while improving the quality of the target product , as the catalyst used is a catalyst, additionally containing 4- 3-methylcarboxyethyl) -2,6-di-tert-butyl sodium phenol t at the following content, wt.%: 4- $ -methylcarboxyethyl) 2, 6-di-tert-butylphenol t sodium 57.2-3.2, 2,6-di-tert-butylphenol t potassium 5,6-0,2, 2,6-di-tert-butylphenol Else, while the indicated components of alkali metals are used in an amount of 1.5-10 mol.% From 2,6-di-tert-butylphenol in terms of the amount of 4- 3-methylcarboxyethyl) -2 , 6-di-tert-butylphenol t sodium and 2,6-di-tert-butylphenol t potassium.