KR820001603B1 - Process for the preparation of 2,2'-bis(4-substitude phenol)sulfur compounds - Google Patents

Abstract

The title compds.(II; R = C1-12 alkyl, C3-12 cycloalkyl,C7-11 aralkyl), useful as photostabilizers,polyolefin reformers and lubricating oil additives, were prepd. by the reaction of I and S2CI2 at -10-40≰C in-the presince of Lewis acid catalyst. Thus, 43.2 g p-cresol was treated with 22.6 g S2CI2 at 0-10≰C for 2 hr in the presence of 0.5 g ZncI,and the reaction products were stirred for 2 hr to give 42.8g 2,2'-bis(4-methylphenol)sulfides(m.p. 112-114≰C).

Description

Method for producing 2,2'-bis (4-substituted phenol) sulfides

The present invention relates to an improved process for the preparation of 2,2'-bis (4-substituted phenol) sulfides useful as light stabilizers, pulley olefin modifiers, lubricant additives and their preparation intermediates. The invention also relates to a 2,2'-bis (4-cumylphenol) sulfide which is a novel compound.

Usually, 2,2'-bis (4-substituted phenol) sulfides are prepared by reacting a corresponding 4-substituted phenol with sulfur dichloride. However, the continuous sulfidation at the sulfide 6 produced in this way involves multinuclear byproducts. The chemical equilibrium of sulfur dichloride is represented by

Disulfides and other polysulfides obtained as by-products make the reaction more complicated. Therefore, in most cases the final product is disadvantageously obtained in dendritic form, and the yield is also low.

In particular, 2,2'-bis (4-third-butylphenol) sulfide was prepared by reacting 4-third-butylphenol with sulfur dichloride. For example, this reaction was carried out at a temperature of 20 to 30 ° C. in carbon tetrachloride, but since the final product was obtained in a dendritic form, a molecular weight measurement method (G.Katsui and H.Hisayama; Vitamin, vol. It was only a rough measure of its identity.

In the past, 4-, 3-amylphenol was reacted with sulfur dichloride in dichloroethane to prepare 2,2'-bis (4--3-amylphenol) sulfide. After the reaction mixture was heated to reflux, the crude product produced by fractional distillation under reduced pressure was purified by recrystallization to give a final product, but the yield was as low as 11% (US Pat. No. 2,971,940).

Previously, 2,2'-bus (4-methylphenol) sulfide was prepared by reacting p-cresol with sulfur dichloride in petroleum ether at room temperature. This crude product was then crystallized from toluene to give a final product with a yield of only 22% (W.S.Gump and J.C. Vitucci; American Chemical Society, Vol. 67, pp. 238 (1945)).

In general, in the case of using the above-described methods for the preparation of 2,2'-bis (4-substituted phenol) sulfides, the reaction mixture takes the form of a resinous phase, which not only requires a difficult operation but also yields a yield. Also very low. For this reason, these methods are uneconomical and inadequate from an industrial point of view. In view of the above-described technical aspects, in the method for producing 2,2'-bis- (4-substituted phenol) sulfides by reacting 4-substituted phenol with sulfur dichloride, the production of by-products can be completely suppressed. It was an important technical problem to improve the proportion of the product and to improve the way in which the reaction mixture can be subjected to the usual post-treatment operation to obtain the desired product fairly easily and with good yield.

It is an object of the present invention to provide an improved process for the preparation of 2,2'-bis (4-substituted phenol) sulfides. It is another object of the present invention to provide a method for producing 2,2'-bis (4-substituted phenol) sulfides which suppresses the formation of by-products. It is yet another object of the present invention to provide a method for producing 2,2'-bis (4-substituted phenol) sulfides that separates a desired product in high yield, and to obtain a desired product relatively easily and with good yield. It is an object of the present invention.

It is another object of the present invention to provide a 2,2'-bis (4-cumylphenol) sulfide which is a novel compound useful as an intermediate for the preparation of light stabilizers.

These objects can be achieved by a method of reacting the 4-substituted phenol of the following general formula (I) (hereinafter referred to as phenol reactant) with sulfur dichloride at -10 to 40 ° C in a hydrocarbon solvent in the presence of a Lewis acid catalyst.

Wherein R is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 11 carbon atoms.

In this way, 2,2'-bis- (4-substituted phenol) sulfides having the following general formula (II) as defined by R above can be produced industrially quite advantageously.

According to the present invention the phenol reactant is dissolved in a hydrocarbon solvent and then reacted with sulfur dichloride. Except for compounds having the formula (I) in which R is 3-octyl, the phenol reactant is reacted with sulfur dichloride after all or part of it is suspended in a hydrocarbon solvent.

The crude product in the process of the present invention can be easily separated as a solid by removing the solvent by steam distilling the reaction mixture after completion of the reaction. If the product is naturally precipitated from the reaction mixture, it can be separated directly by an industrially significant filtration operation. In this case, the mother liquor from which the product is separated contains only a small amount of unreacted phenols and by-products, so that there is no adverse effect on the properties of newly produced 2,2'-bis (4-substituted phenol) sulfides Can be used. In addition, when the solubility of the product is lacking in the mother liquor, the yield of the separated product is further increased by recycling the mother liquor. This phenomenon is a significant advance over previous technologies from an industrial standpoint because it saves solvent and reduces costs, and also completely eliminates environmental pollution problems.

Further, by reacting sulfur dichloride with 4-cumylphenol by the method of the present invention, a novel compound represented by (4-cumylphenol) sulfide is obtained.

The phenol reactant used by the method of the present invention is 4 having the following structural formula (I) which is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 11 carbon atoms. -Substituted phenols.

Specific examples of these include p-cresol, 4-ethylphenol, 4-n-propylphenol, 4-isopropylphenol, 4-n-butylphenol, 4-second 2-butylphenol, 4-third 3-butylphenol , 4-n-amylphenol, 4-isoamylphenol, 4-ze3-amylphenol, 4-n-hexylphenol, 4-cyclohexylphenol, 4-n-heptylphenol, 4-ze3-octylphenol, 4-nonylphenol, 4-dodecylphenol, 4-cumylphenol (4-α, α-dimethylbenzylphenol), and the like. Among these compounds, p-clesol, 4-ethylphenol, 4-third-butylphenol, 4-third-amylphenol, 4-cyclohexylphenol, 4-third-octylphenol, 4-nonylphenol and 4 Cumylphenol is preferred.

Hydrocarbon solvents used in the process of the present invention are solvents commonly used. Specific examples thereof include aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylene, and colobenzene, linear and branched aliphatic saturated hydrocarbons such as butane, pentane, hexane, heptane, isohexane, isoheptane and isooctane, Unsubstituted or alkyl-substituted alicyclic hydrocarbons such as cyclopentane, cyclohexane and methanecyclohexane and halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane and trichloroethane. These solvents can be mixed and used. However, when the phenol reactant is 4-third-octylphenol, aromatic hydrocarbon solvents should be used.

Specific examples thereof include benzene, toluene, xylene, ethylbenzene, cumene, chlorobenzene, o-ditlobenzene, and the like. Of these, benzene, toluene and chlorobenzene are particularly preferred. These solvents can also be used in combination. The amount of solvent used is wide, but generally 0.5 to 10 volume ratio is used, and preferably 2 to 5 volume ratio, based on the weight ratio of phenol reactants.

In the method of this invention, it is preferable to make 1 mol of sulfur dichlorides react for every 2 mol of phenol reactants. However, the amount of sulfur dichloride can be used within the range of 0.8 to 1.5 moles. In carrying out the reaction of sulfur dichloride to the phenol reactant, it is preferable to add sulfur dichloride dropwise to the phenol reactant ben solution in a hydrocarbon solvent in order to achieve the object of the present invention. The addition rate is preferably adjusted to continue to generate hydrogen chloride gas generated by the reaction. If necessary, sulfur dichloride and a hydrocarbon solvent may be added to the solution in the form of a mixture.

In the method of the present invention, the reaction should be carried out at a temperature of -10 to 40 캜. If the reaction temperature is lower than -10 ℃, the reaction time is too long, and if the reaction temperature is higher than 40 ℃, the purity and yield of the product is greatly reduced. A temperature range of -10 to 20 ° C is preferred, with a temperature range of 0 to 10 ° C being most preferred.

The reaction of the phenolic substance described above with sulfur dichloride proceeds without a catalyst. In the prior art, since the reaction rate is very low and the reaction is very complicated, it is obvious that in most cases, a dendritic reaction mixture is formed, so that the purity and yield of the product are very low. The process of the present invention is characterized in that the reaction proceeds very smoothly using Lewis acid as a catalyst to greatly improve the purity and yield of crude products. As a result of using the catalyst, sulfur dichloride is consumed as soon as sulfur dichloride is added to the reaction system, and thus the reaction is completely terminated with the addition of sulfur dichloride. Specific examples of Lewis acids are aluminum chloride, zinc chloride, tin tin chloride and ferric chloride. Of these compounds, zinc chloride is particularly preferred. A very small amount of catalyst is used, but the effective amount of the catalyst is usually 0.001 to 0.1 mol per mol of sulfur dichloride.

In carrying out the process of the invention, the phenolic reactant is dissolved or suspended in a hydrocarbon solvent and then a Lewis acid catalyst is added thereto. Sulfur dichloride is added dropwise thereto while maintaining this solution or suspension at a temperature of -10 to 40 ° C, preferably at a temperature of -10 to 20 ° C. After the addition is complete, the resulting reaction mixture is stirred at this temperature for 1 to 5 hours. Next, air is introduced into the reaction mixture to remove residual hydrogen chloride gas dissolved in the solvent.

The completion of the reaction mixture is then carried out using one of the following two methods.

(1) If the desired product is dissolved in a solvent, the reaction mixture is distilled off to separate it from the solvent and then cooled to room temperature. The precipitate thus formed is filtered off, washed with water and dried to give a crude product. This crude product is suspended in a small amount of low boiling aliphatic hydrocarbons such as petroleum ether, n-hexane, and then stirred at room temperature to obtain a pure product having a high yield (over 95% in purity).

(2) If the desired product precipitates as crystals from the reaction mixture, these crystals are separated by filtration, washed with a small amount of fresh solvent first, followed by washing with water and drying to obtain the final product. In either method, the product produced is subsequently purified by recrystallization to obtain a high-purity product.

In the case of using the 4-third-octylphenol as the phenol reactant in the process of the present invention, the 4-third-octylphenol is dissolved in an aromatic hydrocarbon (especially benzene, toluene or chlorobenzene) as described above and then Lewis. The sulfur dichloride is reacted at a temperature of −10 to 20 ° C. in the presence of an acid catalyst to prepare 2,2′-bis (4-thi-3-octylphenol) sulfide.

Among the compounds of the present invention, 2,2′-bis (4-cumylphenol) sulfide having the following general structural formula is a novel compound.

This compound is obtained by reacting 4-cumylphenol with sulfur dichloride, and is useful as an intermediate or a precursor for preparing light stabilizers of polyolefins. For example, the Nickel salts of 2,2'-bis (4-cumylphenol) sulfides are more suitable for polyolefins such as pulley propylene when compared to 2,2'-bis (4-thi-octylphenol) sulfides, which are famous as light stabilizers. It gives the above light stability.

2,2'-bis- (4-cumylphenol) sulfide can be manufactured by the method mentioned above. For example, 4-cumylphenol can be produced by reacting sulfur dichloride at a temperature of 0 to 10 캜 in benzene in the presence of zinc chloride.

The present invention will be described in more detail with reference to the following examples. The purity of the product obtained in each example was measured by high performance liquid chromatography or gas chromatography.

Example 1

To the solution resulting from dissolving 43.2 g (0.4 mol) of p-Crenol in 90 ml of cyclohexane, 0.5 g of zinc chloride was added. 22.6 g (0.22 mol) of sulfur dichloride was added dropwise over 2 hours while maintaining the temperature of the solution at 0 to 10 DEG C, and then the resulting reaction mixture was stirred at this temperature for 2 hours. The precipitate thus produced was separated by filtration and washed first with 30 ml of cyclohexane, followed by wool and dried to give 42.8 g of a white product having a melting point of 112 to 114 DEG C and a yield of 87%. This product was a 2,2'-bis (4-methylphenol) sulfide with a purity of 97.5%.

The product was then recrystallized from toluene to obtain a pure product of white prism crystals having a melting point of 116 to 117 캜. Elemental analysis of this material is as follows.

Calculation: C 68.3%, H 5.69%, S 13.0%

Found: C 68.5%, H 5.75%, S 13.4%

Example 2

After mixing the mother liquor remaining in Example 1 with the washing | cleaning liquid, the double 100 ml ratio was used as a solvent. 0.5 g of zinc chloride was added to the resulting solution by newly dissolving 43.2 g (0.4 mol) of p-cresol in this solvent, and the operation of Example 1 was repeated. The melting point was 112-114 ° C. and the yield was high. 45.5g of 92.5% of the product was obtained. This product was a 2,2'-bis (4-methylphenol) sulfide with a purity of 97.5%.

Example 3

60 g (0.4 mol) of 4-third-butylphenol and 1 g of tin tin chloride were suspended in 80 ml of n-hexane. While maintaining the temperature of the suspension at 5 to 15 ° C., 22.6 g (0.22 mol) of sulfur dichloride was added dropwise thereto over 2 hours, and then the resulting reaction mixture was stirred at this temperature for 3 hours. It was. The precipitate thus produced was separated by filtration, firstly washed with 30 ml of n-hexane, then washed with water, and dried to give 53.8 g of a white product having a melting point of 97-98 占 폚 and a yield of 81.5%. This product was a 2,2'-bis (4-third-butylphenol) sulfide with 98% purity.

The product was then recrystallized from n-hexane to give a product of pure white prism crystals having a melting point of 99 to 100 ° C. Elemental analysis of this material is as follows.

Calculated Value: C 72.7%, H 7.87%, S 9.69%

Found: C 72.7%, H 7.99%, S 9.50%

Example 4

After mixing the mother liquor remaining in Example 3 and the washing | cleaning liquid, a double 90 ml ratio was used as a solvent. 60 g of 4-third-butylphenol and 1 g of tin tin chloride were newly suspended in this solvent, and the operation of Example 3 was repeated to find 59.5% of the product having a melting point of 97-99 占 폚 and a yield of 90%. Was obtained. This product was a 2,2'-bis (4-third-butylphenol) sulfide with a purity of 98.6%.

Example 5

32.8 g (0.2 mol) of 4-ze3-amylphenol and 0.5 g of zinc chloride were suspended in 65 ml of n-hexane. 1.3 g (0.11 mol) of sulfur dichloride was added dropwise over 1 hour while maintaining the temperature of the suspension at 0 to 10 DEG C, and then the resulting reaction mixture was stirred at this temperature for 2 hours. The precipitate thus formed was separated by filtration, firstly washed with 30 ml of n-hexane, followed by water and dried to give 32.0 g of a white product having a melting point of 98 to 100 ° C and a yield of 87.5%. This product was a 2,2'-bis (4-third-amylphenol) sulfide with a purity of 98.5%.

Next, the product was recrystallized from n-hexane, whereby a product of pure white prism crystal having a melting point of 100 to 101 ° C was obtained. Elemental analysis of this material is as follows.

Calculated Value: C 73.7%, H 8.43%, S 8.94%

Found: C 73.4%, H 8,61%, S 8.96%

Example 6

35 g (0.2 mol) of 4-cyclohexylphenol and 0.5 g of zinc chloride were dissolved in 170 ml of carbon tetrachloride. 11.3 g (0.11 mol) of sulfur dichloride was added dropwise over about 1 hour while maintaining the temperature of this solution at about 0 to 10 DEG C, and then the resulting reaction mixture was stirred at this temperature for 3 hours. Air was added thereto to remove residual hydrogen chloride gas, and then distilled to separate the reaction mixture and carbon tetrachloride and cooled to room temperature. The precipitate thus formed was separated by filtration, washed with water and dried to give 36.8 g of crude product (theoretical yield 38g) having a melting point of 115 to 119 占 폚. This crude product was 2,2'-bis (4-cyclohexylphenol) sulfide having a purity of 90.0%.

Next, the crude product was suspended in 50 ml of cyclohexane, and the resulting suspension was stirred at room temperature for 10 minutes. The precipitate was separated by filtration and dried to obtain 32 g of a final product having a melting point of 121 to 122 占 폚, a purity of 98.5%, and a yield of 84%. This final product was recrystallized from cyclohexane to give a white product having pure needle crystals with a melting point of 121 to 122 캜. Elemental analysis of this material is as follows.

Calculated value; C 75.4%, H 7.85%, S 8.37%

Found: C 75.5%, H 7.92%, S 8.31%

Example 7

41.2 g (0.2 mol) of 4- (1,3,3,3-tetramethylbutyl) phenol and 0.5 g of zinc chloride were dissolved in 150 ml of benzene. While maintaining the temperature of the solution at 0 to 10 DEG C, 11.3 g (0.11 mol) of sulfur dichloride was added dropwise thereto over about 1.5 hours, and then the resulting reaction mixture was stirred at this temperature for 2 hours. It was done. Air was added thereto to remove residual hydrogen chloride gas, followed by distillation to separate the reaction mixture and benzene, and then cooled at room temperature. The precipitate thus produced was separated by filtration, washed with water and dried to give a crude product having a melting point of 130 to 135 DEG C and a yield of 43.7 g (theoretical yield 44.2 g).

Next, 43.7 g of the crude product was suspended in 50 ml of n-hexane, and the resulting suspension was stirred at room temperature for 5 minutes. The precipitate was separated by filtration and dried to give 39.6 g of a final product having a melting point of 134 to 135 ° C, a purity of 98.0%, and a yield of 89.5%. Elemental analysis of this material is as follows.

Calculation: C 75.97%, H 9.56%, S 7.24%

Found: C 76.05%, H 9.63%, S 7.23%

Example 8

The procedure of Example 7 was repeated except that 150 ml of toluene was used instead of benzene to give a crude product having a melting point of 129 to 135 ° C, a purity of 92.0%, and a yield of 43.5 g. Next, 43.5 g of this crude product was suspended in 50 ml of n-hexane, and then a complete operation was carried out in the same manner as described in Example 7. The final product having a melting point of 134-135 DEG C and a yield of 89.0% was 39.3. g was obtained. This final product was 2.2'-bis4- (1,1,3, -tetramethylbutyl) phenol] sulfide having a purity of 98.0%.

Example 9

Except for using dichlorotin instead of zinc chloride, the operation of Example 7 was carried out in half, yielding a crude product having a melting point of 127 to 131 占 폚, a purity of 91.5%, and a yield of 43.8 g. Next, 43.8 g of this crude product was suspended in 50 ml of n-hexane, and then finished in the same manner as described in Example 7 to obtain a final product having a melting point of 134 to 145 캜 and a yield of 88.2%. 39.0 g were obtained. This final product was 2,2'-bis [4- (1,1,3,3-tetramethylbutyl) phenol] sulfide with 98% purity.

Example 10

Except for using 150 ml of chlorobenzene in Benzedae, the operation of Example 7 was repeated, to obtain a crude product having a melting point of 127 to 128 ° C., a purity of 91.0%, and a yield of 44.0 g. Subsequently, 44.0 g of this crude product was suspended in 50 ml of n-hexane, and then finished in the same manner as described in Example 7, where the final product had a melting point of 134 to 135 DEG C and a yield of 88.7%. This 39.2 g was obtained. This final product was 2,2'-bis4-1,1,3,3-tetramethylbutyl) phenol] sulfide having a purity of 98.0%.

Example 11

42.4 g (0.2 mol) of 4-cumylphenol and 0.5 g of zinc chloride were dissolved in 150 ml of benzene. 11.3 g (0.11 mol) of sulfur dichloride was added dropwise over about 1.5 hours while maintaining the temperature of this solution, and then the resulting reaction mixture was stirred at this temperature for 3 hours. . Air was added thereto to remove residual hydrogen chloride gas, followed by distillation to separate the reaction mixture and benzene, and then cooled to room temperature. The precipitate thus produced was separated by filtration, washed with water and dried to obtain a product having a melting point of 77 to 78 ° C and a yield of 44.6 g (theoretical yield: 45.4 g). This product was a 2,2'-bis (4-cumylphenol) sulfide with a purity of 93.5%. This product was then recrystallized from n-hexane to give a pure needle crystal product having a melting point of 82 to 83 ° C. The material was measured in the form of KBr tablets and the infrared spectrum showed absorption bands at wavenumbers of 3320,2970,1610,1480,1420,1300,1260,1240,1220,815,790 and 710ml¹, and the mass spectrum was 454,439,321,212,195,181,165,119,103,91 and 77 The maximum was at the m / 2 value of. Elemental analysis of this material is as follows.

C (%) H (%) S (%)

Calculated Value (C ₉₀ H ₃₀ O₂S): 79.3, 6.65, 7.05

Found: 70.5, 6.41, 7.07

Claims (1)

In the method of manufacturing the 2,2'-bis (4-substituted phenol) sulfides of the following general formula (II) by making 4-substituted phenol of the following general formula (I) react with sulfur dichloride in a hydrocarbon solvent, A process for producing 2,2'-bis (4-substituted phenol) sulfides of the general formula (II), wherein the reaction is carried out at a temperature of -10 to 40 ° C in the presence of a Lewis acid catalyst.

Where R is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aral group having 7 to 11 carbon atoms.