SU929622A1 - Process fr producing arylalkyl phenols - Google Patents

Description

This invention relates to an improved process for the preparation of aryl alkylphenols, which can be used in the polymer, oil refining and petrochemical pro-. hlolennost x.

A known method for producing alkylphenols by alkylation of dihydric phenols, for example pyrocatechin, with isobutylene at 50 is in the presence of sulfuric acid with a yield of up to 94% 1.

However, when alkylation with styrene technical mixture of phenols of FC-16 in the presence of sulfuric acid, the yield of aryl alkyl phenols is lower and is 82 - 87%.

It is not possible to carry out the alkylation reaction more deeply even with a large excess of sty. because the alkylation reaction is reversible and intermolecular rearrangements and dealkylation proceed in the presence of sulfuric acid. In addition, it is necessary to neutralize the alkylate and wash it with water, which results in acidic wastewater containing phenol, the purification of which greatly complicates the process.

There is also known a method of producing ortho-alkylated pyrocatechins by treating pyrocatechol with olefins (isobutylene, isoamylene, styrene) in the presence of a catalyst and titanium salt of pyrocatechol under pressure of 16 atm with a yield of 60%. The disadvantage of this method is the need for a process.

10 under pressure, which complicates the production technology of alkylphenols and does not provide a high yield of the target product.

The known method of alkylation of a technical mixture of phenols isolated during the processing of brown coal contains: pyrocatechol and its homologues (3-methylpyrocatechol, 4-methylpyrocatechol) in the amount of 87 - 92%, and

20 also other phenols, olefins, such as isobutylene or diisobutylene, at 90-150 ° C, preferably at 110 - in the presence of strong acid cationites, taken in an amount of 10 -, as a catalyst,

25 to 15 wt.% For 40 hours. The yield of alkylation products is 50 to 70% 3.

Significant deficiencies of this

30 of the method is not sufficiently high yield of alkylation products, process duration, large catalyst span, the need for the catalyst to separate from the reaction mixture, its purification and regeneration. In addition, alkyl catalysts of the type of cation exchangers cannot be used repeatedly in the reaction due to nitrogenous bases present in the initial mixture of phenol in an amount of 0.07– 0.13%, U in terms of pyridine.

The closest to the technical essence of the invention is a method for the preparation of arylalkylphenols, I by the interaction of phenol or resorcine with styrene in the presence of oxalic acid dihydrate as an catalyst in an amount of 0.2 to 4 wt. % entered immediately at the beginning of the process. The reaction temperature is 90-20, the yield of the desired product is 90% 4.

However, the alkylation of non-individual and technical mixtures of phenols isolated from the 25 pitched waters of the coal semi-coking process with styrene S in the presence of oxalic acid dihydrate when they are introduced immediately at the beginning of the reaction even with prolonged heating of the reaction Q and a high consumption of catalyst proceeds with low yield alkylation products (56%).

The aim of the invention is to increase the yield of the target product. The goal is achieved by the fact that according to the method of producing aryl alkylphenols by reacting phenols with styrene in the presence of Gdigid1 oxalic acid at 90–150 ° C, the technical mixture of phenols is not used as phenols, and the catalyst and styrene are introduced at the beginning and in the middle of the process.

The initial mixture of phenols, isolated: from the pitch waters of the process, the semi-coking of coal, called FC-16, contains in its composition, respectively,%:

Pyrocatechin 32-43

4-Methylpyrocatechol 13-22 3-Methylpyrocatechin19-22

Dimethyl ethyl pyrocatechin 4-8

Total pyrocatechin and its homologues 50-85 Resorcinol and its homologues8-2

Monometric fe-60

NOLOV10-4

Carrying out the process under these conditions allows you to speed up the reaction, significantly increase the yield of the target products, prevent 65

(due to the fractional introduction of an acidic catalyst) the occurrence of side and secondary processes (intermolecular and intramolecular rearrangements, dealkylation and isomerization of the resulting alkylphenols), as well as to prevent the polymerization of styrene.

Using gas-liquid and thin-layer chromatography methods, it has been proved that the reaction products are mainly monosubstituted pyrocatechols in one position; no side and initial reaction products are detected in the reaction mixture.

It was also established that, when carrying out the reaction by the proposed method, no side reaction of styrene polymerization proceeds. This is evidenced by the absence of precipitation (or turbidity) when merging samples of the reaction solutions into methanol. The absence of oligostable products is confirmed by gas-liquid chromatographic analysis, FC-16, alkylated with styrene at a molar ratio of starting components of 1: 1-1.2 using 2-4% oxalic acid dihydrate at 90-150 ° C for 8-10 hours. The reaction is controlled by a decrease in styrene concentration by gas-liquid chromatography. The reaction is considered complete when styrene is completely exhausted or its end is lost during the reaction.

Upon completion of the alkylation reaction, oxalic acid is decomposed by heating the reaction mass to and incubated for 1-2 hours.

The quantitative yield of alkylation products is achieved at a molar ratio of styrene and technical mixture of phenols equal to 1: 1. The lack of styrene 0.5 mol reduces the yield of alkylphenols (up to 48%). An excess of styrene (1.5 mol per 1 mol of the mixture), although it gives a quantitative yield of the target product, however, requires the removal of an excess amount of styrene (0.3 0.5 mol) from the reaction mixture.

Phenols of the initial mixture were not detected in the alkylation products, i.e. all phenols present in the initial technical mixture were alkylated.

Example 1. (comparative) 100 g of FCh-16 composition:

2,3 - 3,5-Xylenols 2,0 3,4-Xylenols1.5

, Pyrocatechin36

3-Methylpyrocatechin 24 4-Methylpyrocatechin 25 Dimethylpyrocatechin 2.0 2.0 2-Methylresorcin 4,5

Resorcin .3,5

Claims (4)

4-Methylresorcinol 1.5 and 4 g of oxalic acid are added to the beginning of the process, heated to 90 and with: vigorous stirring 104 g (116 ml) of styrene (1: 1 mol) are dripped. After 2 hours, the temperature of the reaction mixture during & - 10 is increased to 140 Cu; it is held for 1-2 hours to decompose the catalyst. The distillation of unreacted wood, the conversion of which is only 56%, produces a technical product - a viscous brown resin, boiling in acetone, diethyl ether, benzene, characterized by the following properties: mg. HOH Acid number, g of product. Density at, g / cm 1.1125 Viscosity at 20 ° С, Pa s 2.34 A low yield of alkylphenols - 56% is due to the introduction of a catalyst at the beginning of the process. Example 2 (comparative). Take 100 g of an SF-16 of the composition indicated in example 1.2 g of hydrochloric acid dihydrate and add 104 g (116 ml) of styrene (1: 1 mol) at 90 ° C. Heat the mixture to 115 ° C, hold for 4 h, then add 2 more g of oxalic acid and then continue the reaction under the conditions of Example 1. A dark brown resin is obtained with the properties: mg. KOH Acid number: g of product Density at 20 ° C, g / cm Viscosity at 20 ° C, Alkylphenol pass-through is 75%. The low yield of the target product is due to the fact that, at a single dosage of styrene, parts occur at its thermopolymerization. Example 3. Take 100 g of FC-1 composition specified in example 1, and 2 g of oxalic acid dihydrate, heated to 90 ° C for 15 min and with vigorous stirring to drip 50.2 g (58 ml) of styrene (molar ratio 1: 0.5). The temperature of the reaction mixture is raised to 115 ° C for JO min and kept at this temperature for 4 hours. Then another 2 g of oxalic acid is added to the mixture and 50.2 g (58 ml) of styrene are added dropwise (the total amount of styrene in Example 116 ml, i.e. 1 mol per 1 mol of FCh-16). Heat the reaction mixture to 140 ° C for 20 minutes and continue the process at this temperature for another 4 hours. Then the reaction mixture is heated to 150 ° C and held for 2 hours to decompose the catalyst. 1.1 5.6 After distilling off unreacted styrene (4.16 g), a technical product is obtained with the properties: Acid number, 24.1 g of product iDensity at, g / cm 1.1167 Viscosity at, Pas 11.80 Alkylphenols yield 96% Example 4. Similar to example 3. The molar ratio of the starting components is 1: 0.5 (SF-16 to styrene, respectively). The yield is 48%. Example 5. Similar to example 3. The molar ratio of the starting components is 1: 1.2 (FCh-16 to styrene, respectively). The yield is 100%. Example 6. Similar to example 3. The molar ratio of 1: 1.5 (FC-16 to styrene). 31.2 g of unreacted styrene is distilled off. The output of alkyllenes - 100%. The resulting reaction mixture of alkylphenols is not separated and is a technical product that meets the technical conditions TU 38-10-1. Appearance Uniform, free from mechanical impurities viscous mobile liquid from brown to dark brown color Density at 20 ° C, g / cm, not higher Acid number, mg per 1 g of product, not more than Viscosity at 20 ° C, Pas, not below Residual styrene content,% by wt., not more than 1.5. Content by. There is no lemon,% Formula of the invention. A method of obtaining aryl alkyl phenols by reacting phenols with styrene in the presence of oxalic acid dihydrate at 90-150 ° C, characterized in yield of the target product, in to honors technical phenols used mixture of phenols, said catalyst and styrene are introduced at the beginning and in the middle. Sources of information taken into account during the examination 1. Author's certificate of Czechoslovakia W 105497, cl. 12 J. 14/02, 1962. 2. Authors certificate of the USSR 297629, cl. C 07 C 39/06, 1971. 3. Copyright certificate Czechoslovakia 124808, cl. 12 about 16, 1967.. 4. USSR author's certificate 297629, cl. C 07 C 39/06 1971 5 (prototype).