JPH06107623A - Production of high-purity 2,4-'-dihydroxy-diphenyl sulfones - Google Patents

Abstract

PURPOSE:To efficiently obtain high-purity 2,4'-dihydroxy-diphenyl sulfones useful as a developer, etc., for thermographic paper. CONSTITUTION:Crude 2,4-dihydroxydiphenyl sulfones obtained by reaction of phenols with sulfuric acid are treated with (1) a mixed solvent of 5-20wt.% lower aliphatic alcohols and 95-80wt.% non-halogen-based aromatic hydrocarbons or (3) a mixed solvent of 10-40wt.% acetic acid esters and 90-60wt.% non-halogen based aromatic hydrocarbons to produce the objective high purity 2,4'- dihydroxydiphenyl sulfones.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing high-purity 2,4'-dihydroxydiphenyl sulfones. More specifically, crude 2,4'-dihydroxydiphenyl sulfone obtained from phenols and sulfuric acid is purified to obtain highly pure 2,4'-dihydroxydiphenyl useful as a developer for thermal paper. The present invention relates to a method for efficiently producing sulfones.

[0002]

2. Description of the Related Art In recent years, various phenol compounds have been developed as a developer for thermal paper. Among them, 2,4 '
-Dihydroxydiphenyl sulfones are expected as extremely useful developers for thermal paper. However,
When 2,4'-dihydroxydiphenyl sulfones are produced by the reaction of phenols and sulfuric acid, a highly pure product usable as a developer for thermal paper cannot be obtained. For example, when 2,4′-dihydroxydiphenylsulfone is produced by the reaction of phenols and sulfuric acid, 2,4′-dihydroxydiphenylsulfone and 4,4′-dihydroxydiphenylsulfone are produced even if the optimum reaction conditions are used. Only a mixture of isomers having a production ratio of about 50:50 by weight can be obtained. Further, when 5-methyl-2,4'-dihydroxydiphenyl sulfone is produced using phenol and p-cresol, or 3,5-dimethyl-2,4'-dihydroxy is produced using phenol and 2,4-xylenol. When diphenyl sulfone is produced, the production ratio of 2,4′-dihydroxy compound is about 80 to 90% by weight. Conventionally, various attempts have been made to purify 4,4′-dihydroxydiphenylsulfones, and efforts have been made to remove the isomer 2,4′-dihydroxydiphenylsulfones. The fact is that there is no report on a purification method for increasing the purity of dihydroxydiphenyl sulfones.

[0003]

Under the circumstances described above, the present invention purifies crude 2,4'-dihydroxydiphenylsulfones obtained from phenols and sulfuric acid to obtain a paper for thermal paper. The object of the present invention is to provide a method for efficiently producing high-purity 2,4′-dihydroxydiphenyl sulfones useful as a colorant or the like.

[0004]

Means for Solving the Problems The present inventors have conducted extensive studies to achieve the above-mentioned object, and as a result, found that the object can be achieved by using a specific solvent as a purification solvent. The present invention has been completed based on this finding. That is, the present invention purifies crude 2,4′-dihydroxydiphenylsulfones obtained by the reaction of phenols and sulfuric acid to produce high-purity 2,4′-dihydroxydiphenylsulfones, As a refining solvent, (1) 5 to 20% by weight of at least one selected from lower aliphatic alcohols and at least one selected from 95 to 95% of non-halogenated aromatic hydrocarbons
80% by weight of mixed solvent, (2) 10 to 40% by weight of at least one selected from ketones and 90 to 60% by weight of at least one selected from non-halogenated aromatic hydrocarbons % And at least one selected from the group consisting of (3) acetic acid esters 10 to 40
High-purity 2,4′-dihydroxydiphenyl sulfone, which is treated by using a mixed solvent consisting of 90% by weight and 90% by weight of at least one selected from non-halogenated aromatic hydrocarbons. The present invention provides a method for manufacturing a class of products.

The present invention will be described in detail below. In the present invention, crude 2,4′-dihydroxydiphenyl sulfones obtained from phenols and sulfuric acid are purified using a specific solvent to produce highly pure 2,4′-dihydroxydiphenyl sulfones. . Examples of the raw material phenols include phenol, o-cresol, m-cresol, 2,3-xylenol, 2,5-xylenol,
At least one ortho-position and para-position such as 3,5-xylenol selected from the group consisting of unsubstituted phenols or a mixture of two kinds, or one selected from these phenols. P-Cresol, 2,4-xylenol, 2,6-xylenol, and a mixture with one kind selected from phenols substituted at two ortho or para positions such as 3,4-xylenol are mentioned. be able to. With respect to the usage ratio of these phenols and sulfuric acid, it is preferable to use them so that the molar ratio is in the range of 2: 1 to 4: 1. The reaction between the phenols and sulfuric acid is usually carried out by heating to a temperature in the range of 100 to 200 ° C,
It is carried out while distilling off the water produced by the reaction out of the system. The method of distilling the reaction product water out of the system is not particularly limited, and may be distilled under reduced pressure, or may be distilled by introducing an inert gas such as nitrogen gas into the reaction system. Alternatively, it may be removed by azeotropic distillation using a suitable solvent. Further, a catalyst can be used in the reaction, if desired. Examples of this catalyst include phosphonic acid, phosphinic acid, phosphoric acid and salts thereof. The amount of these catalysts used is usually 2% by weight or more with respect to sulfuric acid,
It is preferably selected in the range of 5 to 10% by weight.

In the present invention, the crude 2,4'-dihydroxydiphenyl sulfone thus obtained is used as a refining solvent for at least one of 5 selected from (1) lower aliphatic alcohols. -20% by weight and at least 1 selected from non-halogenated aromatic hydrocarbons
95 to 80% by weight of mixed solvent, 10 to 40% by weight of at least one selected from (2) ketones and at least one selected from non-halogenated aromatic hydrocarbons 90 Mixed solvent consisting of ˜60% by weight, or at least one kind selected from (3) acetic acid esters 10 to 40% by weight and at least one kind selected from non-halogenated aromatic hydrocarbons 90 Treatment with a mixed solvent consisting of ˜60% by weight. Examples of the lower aliphatic alcohol in the mixed solvent (1) include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, etc. May be used, or two or more kinds may be mixed and used. Further, as non-halogenated aromatic hydrocarbons,
For example, benzene, toluene, xylene, ethylbenzene, butylbenzene, diethylbenzene, mesitylene,
Simmen, cumene, pseudocumene, etc.
These may be used alone or in combination of two or more. If the ratio of the lower aliphatic alcohols to the non-halogenated aromatic hydrocarbons deviates from the above range, the object of the present invention will not be sufficiently achieved. Examples of the ketones in the mixed solvent (2) include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pentanone, 3-pentanone, 2-heptanone, 4-heptanone, diisobutyl ketone, cyclohexanone, and the like. May be used alone or in combination of two or more. On the other hand, as the non-halogenated aromatic hydrocarbons, the same ones as exemplified in the description of the non-halogenated aromatic hydrocarbons in the mixed solvent of the above (1) can be mentioned.
These non-halogenated aromatic hydrocarbons may be used alone or in combination of two or more. If the ratio of the ketones and the non-halogenated aromatic hydrocarbons deviates from the above range, the object of the present invention cannot be fully achieved.

Further, as the acetic acid ester in the mixed solvent of the above (3), for example, methyl acetate, ethyl acetate,
Examples thereof include propyl acetate and butyl acetate, and these may be used alone or in combination of two or more kinds. On the other hand, as the non-halogenated aromatic hydrocarbons, the same ones as exemplified in the description of the non-halogenated aromatic hydrocarbons in the mixed solvent of the above (1) can be mentioned. These non-halogenated aromatic hydrocarbons may be used alone or in combination of two or more. If the ratio of the acetic acid ester and the non-halogenated aromatic hydrocarbon deviates from the above range, the object of the present invention cannot be sufficiently achieved. In the method of the present invention, crude 2,4′-dihydroxydiphenyl sulfone obtained by the reaction of phenols and sulfuric acid is added to the mixed solvent, heated and dissolved, and then cooled to obtain an undissolved substance. The isomers of the above are taken out by a known means, for example, a method such as filtration or centrifugation, and then the lower aliphatic alcohols, ketones or acetic acid esters are distilled off from the residual liquid to obtain a desired high purity 2, 4'-dihydroxydiphenyl sulfones are obtained. At this time, the mixing ratio of each component in the mixed solvent and the amount of the mixed solvent used are appropriately determined depending on the purity and the amount of the crude 2,4′-dihydroxydiphenylsulfones used for purification. Further, the heating temperature and the cooling temperature are appropriately selected depending on the type of mixed solvent used. According to the method of the present invention, it is possible to produce 2,4′-dihydroxydiphenylsulfones having a purity of 95% by weight or more by appropriately selecting the purification conditions. Further, since a halogen-based hydrocarbon represented by dichloroethane or o-dichlorobenzene, which has an adverse effect on the environment, is not used as a purification solvent, it can be carried out extremely advantageously in terms of environmental hygiene and industrially.

[0008]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Example 1 (1) Reaction of Phenol and Sulfuric Acid A reactor was charged with 793 g of phenol, 334 g of sulfuric acid and 16.5 g of phosphonic acid, and dehydration reaction was carried out at 150 to 165 ° C. for 3 hours under a reduced pressure of 560 to 260 mmHg, and an outflow was obtained. When 250g was obtained, 165g of phenol was added and 2
The dehydration reaction was performed for 2 hours under reduced pressure of 60 to 100 mmHg to obtain 180 g of effluent. Further, 165 g of phenol was added and dehydration reaction was carried out for 2 hours under a reduced pressure of 260 to 100 mmHg. When the effluent amounted to 140 g, the reaction was terminated, the phenolsulfonic acid was removed by washing with water, and then dried. A dihydroxydiphenyl sulfone isomer mixture was obtained with a yield of 85 mol%. As a result of analysis by high performance liquid chromatography, the composition was 49 wt% of 2,4′-dihydroxydiphenyl sulfone, 50 wt% of 4,4′-dihydroxydiphenyl sulfone, and 1 wt% of other components. (2) Purification 100 g of the isomer mixture obtained in (1) above was dispersed in a mixed solvent of 205 g of xylene and 45 g of isopropanol, and the mixture was heated under reflux for 2 hours. Next, the mixture was cooled to 40 to 30 ° C., the crystals were filtered off and dried to obtain 42 g of 4,4′-dihydroxydiphenyl sulfone. Isopropanol was distilled off from the filtrate, and the precipitated crystals were collected by filtration and dried to obtain 53 g of 2,4′-dihydroxydiphenyl sulfone. As a result of measurement by high performance liquid chromatography, 4,7'-purity of 97.0 wt%
It was dihydroxydiphenyl sulfone and 2,4'-dihydroxydiphenyl sulfone having a purity of 80.5 wt%.

Example 2 (1) Reaction of Phenol with Sulfuric Acid A reactor was charged with 793 g of phenol, 334 g of sulfuric acid and 16.5 g of phosphinic acid, and dehydration reaction was carried out at 150-165 ° C. for 3 hours under a reduced pressure of 560-260 mmHg. When effluent 240g was obtained, 165g of phenol was added to
The dehydration reaction was performed for 2 hours under reduced pressure of 60 to 100 mmHg to obtain 170 g of effluent. Further, 165 g of phenol was added, and dehydration reaction was carried out for 2 hours under a reduced pressure of 260 to 100 mmHg. When the amount of effluent reached 125 g, the reaction was terminated, the phenolsulfonic acid was removed by washing with water, and then dried. 82 mol% of dihydroxydiphenyl sulfone isomer mixture
It was obtained with a yield of. As a result of analysis by high performance liquid chromatography, the composition was 40% by weight of 2,4′-dihydroxydiphenylsulfone, 58% by weight of 4,4′-dihydroxydiphenylsulfone, and 2% by weight of other components. (2) Purification 100 g of the isomer mixture obtained in (1) above was dispersed in a mixed solvent of 220 g of xylene and 30 g of isopropanol, and the mixture was heated under reflux for 2 hours. Next, the mixture was cooled to 40 to 30 ° C., the crystals were separated by filtration and dried to obtain 45 g of 4,4′-dihydroxydiphenyl sulfone. Isopropanol was distilled off from the filtrate, and the precipitated crystals were collected by filtration and dried to obtain 50 g of 2,4'-dihydroxydiphenyl sulfone. As a result of measurement by high performance liquid chromatography, 4,7'-purity of 97.0 wt%
It was dihydroxydiphenyl sulfone and 2,4'-dihydroxydiphenyl sulfone having a purity of 75.5 wt%.

Example 3 (1) Reaction of Phenol with Sulfuric Acid A reactor was charged with 793 g of phenol, 334 g of sulfuric acid, 950 ml of mesitylene and 16.5 g of phosphonic acid, dehydration reaction was carried out under reflux for 6 hours, and then cooled to room temperature. After that, it was filtered to remove the phenolsulfonic acid and then dried. A dihydroxydiphenyl sulfone isomer mixture was obtained with a yield of 85 mol%. As a result of analysis by high performance liquid chromatography, the composition was 51% by weight of 2,4′-dihydroxydiphenylsulfone, 48% by weight of 4,4′-dihydroxydiphenylsulfone, and 1% by weight of other components. (2) Purification 100 g of the isomer mixture obtained in (1) above was dispersed in a mixed solvent of 160 g of xylene and 90 g of methyl ethyl ketone, and the mixture was heated under reflux for 2 hours. Next, the mixture was cooled to 40 to 30 ° C., the crystals were filtered off and dried to obtain 42 g of 4,4′-dihydroxydiphenyl sulfone. Methyl ethyl ketone was distilled off from the filtrate, the precipitated crystals were collected by filtration, dried and then recrystallized with a mixed solvent of water / methanol to obtain 43 g of 2,4'-dihydroxydiphenyl sulfone. Purity 97.0 wt% as measured by high performance liquid chromatography
4,4'-dihydroxydiphenyl sulfone and purity 9
It was 7.0 wt% of 2,4'-dihydroxydiphenyl sulfone.

Example 4 (1) Reaction of Phenol with Sulfuric Acid In a reactor, 793 g of phenol, 334 g of sulfuric acid, and Shel were placed.
lsol A950 ml and phosphonic acid 16.5
After adding g, the mixture was dehydrated under reflux for 6 hours, cooled to room temperature, filtered to remove phenolsulfonic acid, and then dried. A dihydroxydiphenyl sulfone isomer mixture was obtained with a yield of 80 mol%. As a result of analysis by high performance liquid chromatography, the composition was 52% by weight of 2,4'-dihydroxydiphenylsulfone, 47% by weight of 4,4'-dihydroxydiphenylsulfone, and 1% by weight of other components. (2) Purification 100 g of the isomer mixture obtained in (1) above is dispersed in a mixed solvent of 155 g of mesitylene and 95 g of butyl acetate,
The mixture was heated under reflux for 2 hours. Next, it was cooled to 40 to 30 ° C., and the crystals were separated by filtration and dried to obtain 45 g of 4,4′-dihydroxydiphenyl sulfone. Butyl acetate was distilled off from the filtrate, and the precipitated crystals were collected by filtration and dried to obtain 41 g of 2,4′-dihydroxydiphenyl sulfone. As a result of measurement by high performance liquid chromatography, 4,4'-dihydroxydiphenyl sulfone having a purity of 96.5 wt% and 2,4 'having a purity of 97.0 wt% were obtained.
-Dihydroxydiphenyl sulfone.

Example 5 (1) Reaction of phenol with 2,4-xylenol 416 g of 2,4-xylenol and 334 of sulfuric acid were placed in a reactor.
g, Shellsol AB (2000 ml) and phosphonic acid (16.5 g) were charged, dehydration reaction was performed under reflux for 3 hours, and then 384 g of phenol was added and dehydration reaction was performed for 4 hours. After cooling to room temperature, the precipitated crystals were collected by filtration, washed with a dilute alkaline solution, washed with water to remove phenolsulfonic acid, and dried. An isomer mixture of dihydroxydiphenyl sulfone derivatives was obtained with a yield of 80 mol%. As a result of analysis by high performance liquid chromatography, the composition was 3,5-dimethyl-2,4'-dihydroxydiphenylsulfone (mp.176 ° C) of 87 wt% and the other components of 13 wt%. (2) Purification 100 g of the isomer mixture obtained in (1) above was dispersed in a mixed solvent of 150 g of mesitylene and 90 g of methyl isobutyl ketone, refluxed for 2 hours, cooled to 40 ° C. or lower, and filtered. The methyl isobutyl ketone was distilled off from the filtrate to obtain 67 g of 3,5-dimethyl-2,4'-dihydroxydiphenyl sulfone. As a result of measurement by high performance liquid chromatography, the purity was 97.5 wt%. Example 6 100 g of the isomer mixture obtained in Example (1) was dispersed in a mixed solvent of 140 g of xylene and 100 g of butyl acetate, refluxed for 2 hours, cooled to 40 ° C. or lower, and filtered. By removing butyl acetate from the filtrate, 3.5
-65 g of dimethyl-2,4'-dihydroxydiphenyl sulfone was obtained. As a result of measurement by high performance liquid chromatography, the purity was 97.0 wt%.

[0013]

According to the method of the present invention, crude 2,4'-dihydroxydiphenyl sulfone obtained from phenols and sulfuric acid is purified by using a specific solvent to obtain a thermal paper developer. Useful high-purity 2,4'-dihydroxydiphenyl sulfones can be efficiently obtained.

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Claims (4)

[Claims] 1. Purification of crude 2,4′-dihydroxydiphenylsulfones obtained by the reaction of phenols and sulfuric acid to produce high-purity 2,4′-dihydroxydiphenylsulfones. At least one selected from lower aliphatic alcohols as a solvent 5
High-purity 2,4'-characterized in that treatment is carried out using a mixed solvent consisting of 20% by weight and 95-80% by weight of at least one selected from non-halogenated aromatic hydrocarbons.
A method for producing dihydroxydiphenyl sulfones. 2. Purification of crude 2,4′-dihydroxydiphenylsulfones obtained by the reaction of phenols and sulfuric acid to produce high-purity 2,4′-dihydroxydiphenylsulfones. As the solvent, a mixed solvent consisting of 10 to 40% by weight of at least one kind selected from ketones and 90 to 60% by weight of at least one kind selected from non-halogenated aromatic hydrocarbons is used,
A method for producing high-purity 2,4′-dihydroxydiphenylsulfones, which comprises treating. 3. Purification of crude 2,4′-dihydroxydiphenylsulfones obtained by the reaction of phenols and sulfuric acid to produce high-purity 2,4′-dihydroxydiphenylsulfones. As the solvent, a mixed solvent of 10 to 40% by weight of at least one selected from acetic acid esters and 90 to 60% by weight of at least one selected from non-halogenated aromatic hydrocarbons is used. A method for producing high-purity 2,4′-dihydroxydiphenylsulfones, which comprises treating 4. The highly pure 2,4′-dihydroxydiphenyl according to claim 1, 2 or 3, wherein the 2,4′-dihydroxydiphenyl sulfone is 2,4′-dihydroxydiphenyl sulfone obtained from phenol as a raw material. Method for producing sulfones.