RU2355674C1 - Method of 4-biphenylmetacrylate obtainment - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention concerns organic compound synthesis, particularly method of obtaining 4-biphenylmetacrylate of the formula

. Obtained compound is applied in production of heat and weather resistant polymer materials. Claimed method involves dissolution of 4-phenylphenol in 10 wt % aqueous solution of caustic soda, further dosage of acylating agent in the form of metacrylic acid anhydride agent in reaction mix preliminarily cooled to 0-(+5°)C at such rate so as to keep the mix temperature below +10°C at molar ratio of 4-phenylphenol and metacrylic acid anhydride of 1:(1.1-1.5), reaction mix maturing at room temperature with stirring, organic layer extraction, flushing by alkali solution, and drying.

EFFECT: enhanced output of 4-biphenylmetacrylate, admixture content of non-reacted 4-phenylphenol reduced to 0,003-0,005 wt %.

3 cl, 1 tbl, 10 ex

Description

The invention relates to the field of synthesis of organic compounds, and in particular to a method for producing 4-biphenylmethacrylate of the general structural formula

which is used primarily in the production of heat-resistant and weather-resistant polymer materials.

The inventors faced the task of developing a method for producing 4-biphenylmethacrylate, which would give the maximum yield and purity of the product, since any impurities in 4-biphenylmethacrylate complicate the process of its (co) polymerization.

A known method of producing 2-biphenylacrylate, comprising the following steps. At a temperature of 20-25 ° C, acrylic acid chloride is added to a mixture containing pre-dried benzene, o-phenylphenol and triethylamine at a dropping funnel at a molar ratio of o-phenylphenol and acrylic acid chloride of 1: 1.1. The reaction proceeds in a nitrogen atmosphere. The reaction mixture was stirred for 4 hours, then filtered and washed with a 5 wt.% Aqueous sodium hydrogen carbonate solution and twice with water. The organic benzene layer was dried over sodium sulfate. Benzene is removed by vacuum. The yield of 2-biphenylmethacrylate is 64 wt.%.

(T. Ishikawa "Preparation and Properties of Polymers Anchoring Biphenyl-2-ol", Bull. Chem. Soc. Jpn., 56, 2177-2178, 1983).

The disadvantage of the described method is the low yield of the final product - 2-biphenylacrylate. Since the yield of 2-biphenylacrylate is low, a large amount of unreacted o-phenylphenol and acrylic acid chloride remains as a result of the synthesis. By washing with a 5 wt.% Sodium bicarbonate solution, these products cannot be removed, and another cleaning method is not indicated in the article. It is not possible to obtain a high purity monomer by this method.

The synthesis of 4-biphenylmethacrylate is known, including the dissolution of 4-phenylphenol and triethylamine, an acceptor of hydrogen chloride in tetrahydrofuran, followed by the addition of methacrylic acid chloride at such a rate as to maintain moderate boiling. The reaction proceeds in a nitrogen atmosphere. The reaction mixture is boiled for 4 hours, then it is cooled, the precipitated white precipitate of the amine salt is filtered off, washed with ether, water is added to improve the separation of the organic layer. The filtrate is washed successively with water, 5 wt.% Hydrochloric acid solution and 5 wt.% Soda solution. Dried over magnesium sulfate. After removal of the solvent by evaporation, a white precipitate of 4-biphenylmethacrylate is obtained. It is purified by recrystallization from n-hexane. The yield of 4-biphenylmethacrylate is 60-70 wt.%.

(G.O.P. Alberda van Ekenstein "Polymerization of 4-biphenyl methacrylate", Eur. Polym. J., v. 25, No. 2, 111-115, 1989).

The disadvantages of the described method for producing 4-biphenylmethacrylate are the low yield of the final product, the presence of a significant amount of impurities in the form of β-chloropropionic or β-chloroisobutyric acid esters resulting from the addition of hydrogen chloride to a double bond, the presence of the starting amine and unreacted 4-phenylphenol. In addition, solid wastes in the form of amine salts are present in this process. The presence of these components complicates the process; the utilization of a solid amine salt, regeneration of the starting amine, and repeated recrystallization of 4-biphenylmethacrylate are required.

The prototype of the proposed method for producing 4-biphenylmethacrylate is a method for its preparation by dissolving p-phenylphenol in a 5 wt.% Aqueous solution of sodium hydroxide, then adding methacrylic acid chloride at a molar ratio of p-phenylphenol and methacrylic acid chloride in the amount of 1 hour :one. Next, the reaction mixture was stirred for 1 hour at room temperature, then extracted with ether. The extract was washed with an alkali solution and water until neutral, dried over anhydrous magnesium sulfate, the ether was distilled off, and the residue was fractionated twice in vacuo. Colorless crystals are obtained with a melting point of 111-112 ° C. The yield of 4-biphenylmethacrylate is 50 wt.%.

(M.M.Koton et al. “Cases of Polymerization Difficulty in the Monomers of Some Aryl Methacrylates”, Journal of General Chemistry, vol. XXVIII, issue 2, p. 419, 1958).

The main disadvantage of the prototype is the low yield of 4-biphenylmethacrylate. In addition, the reproduction of this method showed the presence in the final product of a significant amount of 4-phenylphenol, which is about 0.25 wt.%.

The aim of the invention is to increase the yield of 4-biphenylmethacrylate and its degree of purity.

To achieve this goal in a method for producing 4-biphenylmethacrylate by dissolving 4-biphenylphenol in an aqueous solution of sodium hydroxide, dosing the acylating agent, holding the reaction mixture with stirring at room temperature, extracting the organic layer, washing it with an alkaline solution and drying, it is proposed to dissolve 4-phenylphenol in a 10 wt.% aqueous solution of caustic soda, and methacrylic acid anhydride is used as the acylating agent, which is metered in previously cooled to 0 - (+ 5) ° С eaktsionnuyu mixture at such a rate that the temperature did not exceed + 10 ° C, with a molar ratio of 4-phenylphenol and methacrylic anhydride ratio of 1: (1.1-1.5).

In the proposed method, the organic layer is extracted with benzene, and washing is carried out successively twice with 10 wt.% And 20 wt.% Aqueous sodium hydroxide solution and 20 wt.% Sodium chloride solution until the washings are neutral. The organic layer was dried over sodium sulfate at room temperature.

The invention is illustrated by the following examples.

Example No. 1

In a reactor equipped with a stirrer, a refrigerator, a thermometer and a dropping funnel, 92.0 g (0.54 mol) of 4-phenylphenol are charged, 450 ml of a 10% sodium hydroxide solution are poured. The mixture is heated to 60-80 ° C until complete dissolution of 4-phenylphenol. With a constantly working stirrer, cool the mixture to room temperature. Then 450 ml of ice water are charged into the reactor. 112 g (0.73 mol) of methacrylic acid anhydride are metered into the reaction mass cooled to 0-5 ° C so that the temperature in the reactor does not exceed + 10 ° C. Then the temperature of the reaction mixture was brought to room temperature (18-20 ° C) and stirring was continued for another 1.5 hours at this temperature. After the exposure time, 700.0 ml of benzene are added to the reactor and the contents of the reactor are stirred for 30-45 minutes until complete separation. 10 minutes before the end of mixing, add 100 ml of chilled water for a more complete separation of the organic layer. The mixture is transferred to a separatory funnel, the lower aqueous layer is removed, and the organic layer is washed successively twice with 100 ml of a 10 wt.% Aqueous solution of sodium hydroxide, twice with 100 ml of a 20 wt.% Solution of sodium hydroxide and a 20% aqueous solution of sodium chloride until the washings are neutral. . The organic layer was dried over sodium sulfate at room temperature. After removing the solvent, the white precipitate of 4-biphenylmethacrylate is air dried in a fume hood. 122.5 g of 4-biphenylmethacrylate are obtained. The yield is 95%.

The melting point of the obtained 4-biphenylmethacrylate is 111-112 ° C. The content of unreacted starting 4-phenylphenol is 0.003%. Determined by the polarographic method.

Example No. 2

It is carried out according to example No. 1, only they take 103.2 g (0.67 mol) of methacrylic acid anhydride. The molar ratio of 4-phenylphenol: MAC anhydride is 1: 1.24.

Received 109.5 g of 4-biphenylmethacrylate. The yield is 85%. The initial 4-phenylphenol content is 0.005%.

Example No. 3

It is carried out according to example No. 1, only take 92.4 g (0.6 mol) of MAA anhydride. The molar ratio of 4-phenylphenol: MAC anhydride is 1: 1.1.

Received 103.8 g of 4-biphenylmethacrylate. The yield is 80%. The initial 4-phenylphenol content is 0.005%.

Example No. 4

It is carried out according to example No. 1, only take 124.7 g (0.81 mol) of methacrylic acid anhydride. The molar ratio: 4-phenylphenol: MAC anhydride is 1: 1.5. Received 122 g of 4-biphenylmethacrylate. The yield is 95%. The initial 4-phenylphenol content is 0.003%.

Examples No. 5-10 (for comparison)

The synthesis conditions, yield and purity of the 4-biphenylmethacrylate product are shown in the table. The reaction product was isolated, purified and dried according to example No. 1 (except for the prototype).

The conditions for obtaining 4-biphenylmethacrylate, its yield and impurity content No pp Source reactive components The molar ratio of reacting components The reaction temperature, ° C The concentration of an aqueous solution of caustic soda,% Yield, wt.% The impurity content of 4-phenylphenol, wt.% one 2 3 four 5 6 7 According to the invention one. 4-phenylphenol
Anhydride MAK 1: 1.35 0-10 10 95.0 0.003 2. 4-phenylphenol
Anhydride MAK 1: 1.24 0-10 10 85.0 0.005 3. 4-phenylphenol
Anhydride MAK 1: 1,1 0-10 10 80.0 0.005 four. 4-phenylphenol
Anhydride MAK 1: 1,5 0-10 10 95.0 0.003 For comparison 5. According to the prototype
p-phenylphenol
MAH chloride    1: 1 Room    5   50,0   0.25 6. 4-phenylphenol
Anhydride MAK 1: 1 0-10 10 75.0 0.15 7. 4-phenylphenol
Anhydride MAK 1: 1.35 0-10 5 70.0 0.15 8. 4-phenylphenol
Anhydride MAK 1: 1.35 twenty
(indoor) 10 67.0 0.25 9. 4-phenylphenol
MAH chloride 1: 1.35 0-10 10 43.0 0.2 10. 4-phenylphenol
MAH chloride 1: 1.25 0-10 10 35.0 0.22

From the data in the table it follows that the proposed method for producing 4-biphenylmethacrylate can increase its yield to 80.0-95.0 wt.%, Which is significantly higher than the prototype, where the yield is 50 wt.%, And the content of unreacted 4-phenylphenol is 0.003 -0.005 wt.% Instead of 0.25 wt.% According to the prototype (see examples No. 1-4 in comparison with No. 5).

Examples No. 6-10 show that the implementation of the method for producing 4-biphenylmethacrylate under conditions outside the scope of the claimed does not allow to achieve the required yield and degree of purity of the product.

The implementation of the method of producing 4-biphenylmethacrylate with a molar ratio of 4-phenylphenol and MAH anhydride that goes beyond the claimed, for example 1: 1, leads to a decrease in yield and an increase in the residual 4-phenylphenol content (see example No. 6 in comparison with No. 1- four). When the ratio of 4-phenylphenol and MAA anhydride is 1: 1.6, the yield of 4-biphenylmethacrylate is quite high, but there remains a significant amount of unreacted MAA anhydride, which requires a multiple increase in the number of washes, which is not economically feasible, in addition, the amount of wastewater increases.

In the proposed method, the synthesis is carried out in 10 wt.% Aqueous sodium hydroxide solution. A decrease in the concentration of the solution, for example, to 5 wt.% Leads to a decrease in the rate of phenolate formation, incomplete exhaustion of the initial 4-phenylphenol, which leads to a lengthening of the process, a decrease in yield and an increase in impurities (see example No. 7 in compare with No. No. 1 -four).

Increasing the concentration of an aqueous solution of caustic soda, for example, up to 15 wt.% Leads to the hydrolysis of 4-biphenylmethacrylate and an increase in the amount of impurities.

The process of interaction of 4-phenylphenol and MAA anhydride occurs at a low temperature of 0-10 ° C. Raising the temperature to room temperature (20 ° C) reduces the yield of 4-biphenylmethacrylate and its purity, since side reactions occur at this temperature, such as hydrolysis of MAK anhydride and polymerization of ether (see example No. 8 in comparison with No. 1-4).

Examples No. 9-10 show that the implementation of the method of producing 4-biphenylmethacrylate by reacting 4-phenylphenol with acid chloride, and not with MAC anhydride, gives a very low yield and a large amount of impurity (see examples No. 9-10 in comparison with No. No. 1-4).

Thus, only the proposed method leads to the production of 4-biphenylmethacrylate of high quality and with a good yield. The use of MAK anhydride as an acylating agent in the claimed method, and not acid chloride, as in world practice, excludes the attachment of hydrogen chloride to a double bond and the production of a significant amount of impurities in the form of β-chloropropionic or β-chloroisobutyric acid esters.

Claims (3)

1. The method of obtaining 4-biphenylmethacrylate of the General structural formula

,
comprising dissolving 4-phenylphenol in an aqueous solution of sodium hydroxide, dosing the acylating agent, keeping the reaction mixture under stirring at room temperature, extracting the organic layer, washing it with an alkaline solution and drying, characterized in that 4-phenylphenol is dissolved in a 10 wt.% solution sodium hydroxide, and methacrylic acid anhydride is used as the acylating agent, which is dosed into the reaction mixture pre-cooled to 0 ÷ (+5) ° С at such a rate that the temperature of the mixture does not exceed + 10 ° C in a molar ratio of 4-phenylphenol and methacrylic anhydride ratio of 1: (1.1-1.5). 2. The method of producing 4-biphenylmethacrylate according to claim 1, characterized in that the extraction of the organic layer is carried out with benzene. 3. The method of producing 4-biphenylmethacrylate according to claim 1, characterized in that the washing of the organic layer is carried out successively twice with 10 and 20 wt.% Aqueous sodium hydroxide solution and 20 wt.% Aqueous sodium chloride solution until neutral.