SU1685920A1 - Method for obtaining esters of @@@-(4-hydroxy-3,5-di-tret-butylphenyl)propionic acid - Google Patents

Abstract

The invention relates to carboxylic acid esters, in particular the preparation of esters of (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid, used in polymer production and in agriculture. The goal is to improve the quality of the target product, to intensify and simplify the process. It is carried out by re-etherification of the methyl ester of this acid with polyhydric alcohols at 135-180 ° C in a stream of inert gas in the presence of a catalyst. As the latter, the following composition is used, wt%: methylcarboxyethyl) -2,6-di-tert-butylphene n sodium 22.8-12, 2,6-di-tert-butylphenoyl potassium 5.1-1 , 8 and 2,6-di-tert-butylphenol - the rest. These alkali metal compounds are used in an amount of 1.5-10 mol% of the methyl ester of the indicated acid, calculated on the sum of the indicated alkali metal compounds. The target esters are separated from the salts and isolated in crystalline form. These conditions allow to obtain the target esters with a yield of up to 94% with a reduction in process time by 2-3 times. 1 tab. Yo

Description

The invention relates to organic chemistry, specifically to the preparation of the esters of ft - (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid, which are 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.

Distinctive features of the process are carrying out the process of transesterification at 135-180 ° C in the presence of a catalyst containing 4- (6-methylcarboxyethyl) -2, b-di-tert-butylfeno / 1 ton of sodium, 2,6-di potassium tert-butylphenol and 2,6-di-tert-butylphenol with the following

the ratio of these components. wt.%:

4- 9-methylcarboxyethyl) -2, b-di-tert-butylphenol sodium 22, 8-12 2,6-di-tert-butylphenol potassium 5.1-1.8 2,6-di-tert-butylphenol alkali metal compounds are used in an amount of 1.5-10.0 mol,% of methyl ester / 3-4 (-hydroxy-3,5-di-tert-butylphenylpropionic acid, esters D {4-hydroxy-3,5- Di-tert-butylphenyl) propionic acid is separated from the salts (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and purified by crystallization.

O 00 SP 45

yoo o

A change in the ratio of the alkali metal components in the catalyst, both in the direction of increasing the content of 4 - (/ 3-methyl carboxyethyl) -216-di-tert-butylphenol — sodium, and in the direction of decreasing it leads to negative consequences. First, The composition of the alkali metal components ensures the formation of a homogeneous mixture of the alkali metal components of the catalyst (2,6-di-tert-butylphenyl) propionic acid and the corresponding alcohol (for example, pentaerythritrate). A change in the composition of the catalyst towards an increase in 2,6-di-tert-butylphenol potassium, respectively, a decrease in 4-3-methylcarboxyethyl) -2,6-di-tert-butylphenol sodium leads to the destruction of the homogeneity of the reaction mass and precipitation of 2,6 -di-tert-butylphenol potassium, resulting in a dramatic change in catalyst activity. This shows an undesirable property associated with the darkening of the reaction mass and the impossibility of obtaining the desired high-quality products. An increase in the content of 4 - ((3-methylcarboxyethyl) -2,6-di-tert-buty l and sodium phenol (with a simultaneous decrease in potassium 2,6-di-tert-butylphenol and potassium) is also undesirable, since an increase in the transesterification reaction time and a decrease in the yield of the target products are observed.

The catalyst is obtained by mixing its constituents or by heating a mixture of potassium hydroxide and sodium hydroxide with 2,6-di-tert-butylphenol in a stream of inert gas at 110-180 ° C for 0.5-2.0 hours, followed by to the resulting methyl ester mixture of [3- {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid.

The composition of the catalyst and its activity is not dependent on the method of its preparation, which is explained by the reaction of sodium 2,6-di-tert-butylphenolate with methyl ester (H4-tyroxy-3,5-di-tert-butylphenyl) pro - pionic acid, as a result of which 2,6-di-tert-butylphenol is regenerated. 2,6-Di-tert-butylphenol potassium does not react with methyl ester (4-hydroxy-3,5-di-tert-5-butylphenyl) propionic acid, and, therefore, when the mixture of sodium hydroxide and potassium hydroxide is heated with 2 , 6-di-tr8t-butylfechol with conversion up to 99.9% forms 2,6-di-tert-butylphenol sodium and 2,6-di-tert-butylphenol potassium. When these phenols are treated with methyl ether P - (4-p droxuga, 5-di-tert-butylphenyl) propionic acid, a catalyst of the following composition is formed: 4-0-methyl-carboxyethyl-di-tert-butylphenol sodium, 2, 6-di-tert-butylphenol t potassium and 2,6 di-tert-butylphenol.

The invention is illustrated by the following examples.

Example 1. Into a reaction flask with a stirrer and an inert gas inlet, 31 g (0.15 g mol) of 2,6-di-tert-butylphenol, 0.6 g (94%) (0.014 g mol) of oxide hydrate are charged. sodium and 0.85 g (85%) (0.0053 g mol) of potassium hydroxide, in a stream of argon is heated to 150 ° C and maintained

1 h with distillation of the water-2,6-di-tert-butylphenol fraction in an amount of 10 g, after which 10 g of 1,6-di-tert-butylphenol and 4.1 g (0.014 g-mole) are added to the reaction mass methyl ester / 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and get 36,7 catalyst, the composition of which and the content of its alkaline components are shown in the table. The content of the components of the catalyst was confirmed by analyte. Next, to 36.7 g of the catalyst of this composition was added 87.9 g (0.3 g mol) of methyl ether / 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and 10.2 g ( 0.075 g mol) pentaerythritol. In argon flow

the mixture is heated for 5 hours at 155-160 ° C under reflux, trapping the liberated methyl alcohol in a condenser, and 1 hour at the same temperature with distillation of 2,6-di-tert-butylphenol. Reaction mass

cooled to 100-95 ° C, dissolved in 100 ml of heptane and filtered. The heptane solution is cooled to 5-10 ° C, the precipitated precipitate is filtered. The yield of pentaerythryl-tetrakis-D {4-hydroxy-3,5-di-tert-butylphenyl) propionate 82 g (93%), so pl. 114-116 ° C, after recrystallization from hepatan, so pl. 116-117 ° C {ft-form).

Example 2. In a reaction flask with a stirrer, reflux condenser and

106 g (0.51 g mol) of 2,6-di-tert-butylphenol, 3.6 g (in terms of 100%) (0.09 g mol) of sodium hydroxide, 0.56 g (0.5 0.01 g mol) of potassium hydroxide in a stream of argon is heated to

135 ° C for 1.5 hours with stripping of 26 g of the water-2,6-di-tert-butylphenol fraction, after which to the reaction mass was added 26 g of 2,6-di-tert-butylphenol and 26.3 g ( 0.09 g mol) of methyl ester of P - (4-hydroxy3, 5-di-tert-butylphenyl) propionic acid and get 134.2 g of catalyst, the composition of which and the content of its alkaline components are confirmed by analysis. From 134.2 g of catalyst, 28.3 g are obtained 4-0

-methylcarboxyethyl) -2,6-di-tert-butyl-nol sodium and 2.42 g 2,6-di-tert-butylphenol potassium, 2,6-di-tert butylphenol - the rest. Next, 292.9 g (1 g mol) of methyl ester (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and 34 g (0.25 g mol) of pentaerythritol are added to 134.2 g of catalyst. In a stream of argon, the mixture is heated for 3 hours at 180 ° C under reflux and 1.5 hours at the same temperature with distillation of 2,6-di-tert-butylphenol.

The reaction mass is cooled to 80-90 ° C, dissolved in 200 ml of isopropyl alcohol (water content 14%), cooled and filtered. The yield is 278 g (94%), after crystallization from heptane pentaerythryl-tetrakis (4-hydroxy-3,5-di-tert-butylphenyl) propionate has so pl. 116-117 ° C (/ 3-form), the mother liquor is acidified and 25 g of (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is isolated by filtration. M.p. 174-175 ° C.

Example 3. In a reaction flask with a stirrer, reflux condenser, and inert gas inlet, 16.5 g (0.08 g mol) of 2,6-di-tert-butylphenol, 0.4 g (0.01 g mol) melted are charged. sodium hydroxide and 0.224 g (0.004 g mol) of potassium hydroxide is heated in a stream of argon for 30 min at 110 ° C and 15 min at 135 ° C, then 2.92 g (0.01 g mol) is added to the reaction mass methyl ester of / - {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and obtain 19.8 g of catalyst, the composition of which and the content of its alkaline components are confirmed by analysis. From 19.8 g of catalyst, 3.14 g of 4- (fl-methylcarboxyethyl) -2,6-di-tert-butyl phenol of sodium and 0.98 g of 2,6-di-tert-butylphenol of potassium are obtained, 2 , 6-di-tert-butylphenol - the rest. Next, 146.18 g of methyl ester (- - {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and 26.5 g (0.25 g mole) of diethylene glycol are added to 19.8 g of catalyst. The mixture in argon flow at 135-140 ° C is heated for 4 hours, the temperature is raised to 160 ° C and the 2,6-di-tert-butylphenol is distilled off. The reaction mass is cooled to 90-95 ° C, dissolved in 150 ml of gasoline, the salt precipitate is filtered off. Yield 3.6 g. When the mother liquor is cooled to 10–15 ° C, a white precipitate of diethylene glycol-bis - / - {4-hydroxy-3,5-di-tert-butylphenol) propionate precipitates. Yield 147 g (94%), m.p. 92-93 ° C. When storing the catalyst residues in air, a mixture of potassium and sodium salts of / - {4-hydroxy-3,5-di-tert-butylphenyl) propionoig is quantitatively formed. f.

(with different).

Example 4 20.6 g (0.1 g-mol |) 2 b-di-tert-butylphenol are loaded into the reaction LP. 0.44 g (91%) (0.00 I g mol) of sodium hydroxide, 0.28 g (0.005 g mol) of potassium hydroxide. Heat in a stream of argon for 30 min at 110 ° C and 15 min at I5 ° C. whereupon 2.92 g (0.01 g mol) of methyl ester of (- 4-hydroxy-3,5-di-tert-butylphenyl) propionic acid is added to the reaction mass and 19.7 g of catalyst are obtained, whose composition and content of its alkaline components are confirmed by analysis. From 19.7 g of catalyst, 3.14 g of 4- 9-methylcarboxyethyl) -2,6-di-tert butylphenol sodium is obtained, 1 g of 2,6-di tert butylphenol and potassium, 2,6-di tert-butylphenol - the rest. Further, to 19.7 of the catalyst, 146.18 g of the methyl ethyl ester of / - (4 hydroxy-3,5-di-tert-butylphenyl) propionic acid and 29 g (0.25 g mol) of thiodiethyl glycol are added. The mixture in an inert gas stream at 145 ° C is heated for 6 h, the temperature is diminished to 160 ° C and 2,6-di tert-boil-nol is distilled off. The reaction mixture is cooled to 90-95 ° C, dissolved in 150 ml of heptane, the precipitate of the catalyst residue is filtered off and dissolved in water. When cooled to 15–20 ° C, white crystals of thiodiethyleneglycol-bis- (4-hydroxy-ZB) di tert-butylphenyl) propionate precipitate out of the organic layer, mp. 71 ° C. yield 151 g (94%). 2.7 g / 3- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid, m.p. 174-175 ° C

Example 5. Into a 1 m reactor equipped with a stirrer, a heat exchange of PM and an inlet for a gas that forms a single system that circulates the gas stream and consists of a heat exchanger, a tank for collecting methyl alcohol (or water) and 2,6-di tert-butylphenol, a blower compressor and a column with zeolite to absorb the residual amount of methanol (or water), put 41.2 kg (0.2 kg mol) of 2,6-di-tert-butylphenol, 0.8 kg (0.2 kg mol) of sodium hydroxide and 0.14 kg (0.0025 kg mol) of potassium hydroxide. Nitrogen is passed into the reactor at a rate of 80 l / min, heated to 130-135 ° C and the water-2,6-di-tert-butylphenol fraction in an amount of 20 kg is distilled off within 2 hours. 5.85 kg (0.02 kg mol) of methyl ester (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid was added to the mass from the reactor. 50 g of catalyst were taken for analysis. Next, the catalyst is added

117 Y "g AND 5 m mol) of methyl ester D (4 GIDPOKOI-3.5-DI tert butylphenyl) propionic acid and 79.5 kg (0.75 kg mol) of diethylene glycol and at 135-140 ° C distilled 2.6 -di-tert-bu-1-phenol and the methyl alcohol formed in the settling tank for 5-6 hours. When conversion of methyl (4 hydroxy-3,5-di-ter-butyl-phenyl) propionic acid to 95-98% purge is achieved nitrogen is stopped, cooled to 90-95 ° C. The reaction mass is dissolved in 300 kg of gasoline, washed with water, the organic layer is cooled to 10-15 ° C, the precipitate is filtered. The yield of diethylene glycol bis- {(4-hydroxy-3,5-di-tert-butylphenyl) propionate 582 kg (93%), t pl. 92-93 ° C. 5.6 kg / насыщ {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid are obtained from the aqueous solution by saturation with carbon dioxide; m.p. 174-175 C. Example 6. To the reaction flask is charged 16.5 g (0.008 i mol), 2.6 di tert-butylphenol, 3.14 g (0.01 i mol) 4 (tilcarboxyoyl) 2 6 di tpfi butylphenol a sodium, 0.98 g (0.004 g mol), 2.6-di-tert-butylphenol potassium, stirred for 5 minutes and obtain 20.62 g of catalyst, the composition of which is shown in the table. From 20.62 g of the catalyst of the indicated composition according to the procedure described in Example 1, 3.14 g of 4- (/ methylcarboxyethyl) -2,6-di-tert-butylphenol sodium, 0.98 g of 2,6-di- tert-butanemole capi. 2,6 di-tert-butylphenol ocr ibHoe Next, 146 g (0.5 g mol) of methyl ester (4-hydroxy-3,5-di-tert-butyl nitroxypionic acid and 26 5 g (0.25 g mol) diethylene glycol The reaction is carried out as in example 3 and 147 g (94%) diethylene glycol bis / 3 (4 hydroxy-3 5 di-tert-buhylphenyl) propionate are obtained, mp 92 93 ° C, and 3.6 g of a mixture of salts of ttlich and sodium ((4-hydroxy 3.5-di-tre1-butylphenyl) propionic acid, mp. 24Г. 250PS

Example 7. From 3.7 g (0.0925 g mol) of sodium hydroxide, 0.4 g (0.0071 g mol) of potassium hydroxide and 2,6-di-tert-butylphenol and methyl ether /} - {4-hydroxy-3, 5-di-tert-butylphenyl propionic acid according to the procedure described in Example 1, 100 g of catalyst are obtained, the composition of which is determined by an analytical method. From 100 g of catalysts pi ychp 19 4; 4 (/ 3-meslcarboxyacid) 2 6 sodium diethbufphenol and 1.7 g potassium di-tert-butylphenol. 2,6-di-tert-butylphenol - the rest. To 100 g of catalyst were added 292.3 g (1 g-mol) of methyl ester (4-hydroxy-3.5 ditert-butylphenyl) propionic acid and 34 g (0.25 g mol) of pentaerythritol. The reaction is carried out as in Example 2 and 72% of the desired product is isolated; mp 115-116 ° C.

Example 8. Of 2.34 g (0.0585 g mol)

0 sodium hydroxide, 2.75 g (0.049 g mol) of potassium hydroxide, 2,6-di-tert-butylphenol and (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid methyl ester according to the procedure described in example 1, get

5 200 g of catalyst, whose composition is determined by an analytical method. To 200 g of catalyst were added 292.3 g (1 g mol) of methyl ester of / 3- {4-hydroxy-3,5-di-tert-bougylphenyl) propionic acid and 34

0 g (0.25 g mol) of pentaerythritol. The reaction is carried out as in Example 2 and 81% of the desired product is isolated; m.p. 115-116 ° C.

In Example 3 (see table), the catalyst is prepared from 0.4 g (0.01 g mol) of fused

5 (dehydrated) sodium hydroxide and 0.224 g (0.004 g mol) of potassium hydroxide with 16.5 g (0.08 g mol) of 2,6-di-tert-butylphenol. A mixture of 0.01 g of mol of 2.6-di-tert-butylphenool of sodium and 0.004 g of mol of 2,6-di-tert-butylphenol of potassium is initially obtained, and 0.014 g of mol of 2,6-di tert-butylphenol. Of 149.1 g (0.51 g mol) of ft- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid methyl ester, 0.01 g mol is necessary for the preparation of 0.01 g mol 4- 3-methyl carboxyethyl) -2,6-di-tert-butylphenol and sodium, and the same amount (0.01 g mol) of 2,6-di-tert-butylphenol is regenerated. Thus, 2,6-di-tert-butylphenol is consumed only to obtain 0.004 g mol of 2,6-di-tert-butylphenol potassium. It follows from the calculation that, 0.4 g (0.01 g mol) of sodium hydroxide, 0.224 g (0.004 g mol) of potassium hydroxide and 16.5 g (0.08 g mol) of 2,6-di- tert-butylphenol, 3.14 g (0.01 g mol) of 4- (uZ-methylcarboxyethyl) -2,6-di-tert-butylphenol sodium and 0.98 g (0.004 g mol) 2,6- 15.7 g (0.08-0.004) 0.076 g mol of 2,6-di-tert-butylphenol remain in potassium di-tert-butylphenol and potassium in the reaction mass. This composition corresponds to the catalyst:

0

five

0

I L

(ArCNdj mole)

ft .-) k, - L

where (AgOMa) -4- 3-methylcarboxyethyl) -2,6-di-tert-butylphenol sodium, (PhOH) -2,6-di-tert-butylphenol potassium, (PhOH) -2,6-di- tert-butylphenol.

The proposed method makes it possible to shorten the reaction time by a factor of 2 to 3 and to obtain the desired product in a crystalline state in a high yield.

In the proposed method, the use of toxic metals as a catalyst is eliminated due to the use of low toxic components of the catalyst — hindered alkyl alkyls. In addition, the high efficiency of the process allows for the transesterification process without evacuation in an inert gas flow, which makes it possible to utilize the generated methanol. Of the catalyst components additionally

(4-hydroxy-3,5-di-tert-butylphenol) propionic acid and its sodium and potassium salts are obtained, which are used in the national economy.

Claims (1)

The invention of the method of producing esters of / 7- (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid by transesterification of the methyl ester D {4-hydroxy-3,5-di-tert-butylphenyl) propionic acid polyhydric alcohols in inert current gas and increased g.: .., s, .atur in g.units of catalyst, characterized in that, in order to intensify and simplify the process while improving the quality of the target product, the transesterification is carried out at 135-180 ° C and a catalyst containing a-methylcarboxyethyl) -2,6-di-t-butylphenol t sodium, 2,6-di-t-t-butylphenol potassium and 2,6-di-t-t-butylphenol with the following content is used as a catalyst specified components, wt.%: 4 - ((3-methylcarboxyethyl) -2,6-di-tert-butylphenol t sodium 22.8-12, 2,6-di-tert-buty l fe n ol t potassium 5.1-1.8, 2,6-di-tert-butylphenol Else; however, the indicated alkali metal compounds are used in an amount of 1.5-10 mol% of methyl ft - (4-hydroxy-3,5-di-tert-butylphenyl) propionic ester acids in terms of the amount of 4- (fl-methyl-carboxyethyl) -2,6-di-tert-butyl phenol sodium and 2,6-di-tert-butylphenol potassium, and esters (4-hydroxy-3, 5-di-tert-butylphenyl) propionic acid is separated from the salts of - (4-hydroxy-3,5-di-tert-butylphenyl) propionic acid and isolated as crystalline products.