JPS604162A - Purification of bis(4-(aminophenoxy)phenyl)sulfone - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for purifying crude bis[4-(aminophenoxy)phenyl]sulfone.

BisC4-(aminophenoxy)phenyl]sulfone is an extremely useful compound as a raw material for producing polymeric substances with excellent heat resistance, and many methods for its production are known. No., Japanese Patent Application Publication No. 5
7-21864, Japanese Patent Application Laid-Open No. 57-21865, Japanese Patent Publication No. 18960-1982, German Publication No. 1909520, Japanese Patent Publication No. 15020-1987, etc. are known. Although it is possible to obtain target products of considerable purity using these manufacturing methods, recently there has been an increasing demand for products with higher purity, and the crude products obtained by each of the above methods are often further purified. I came. As a purification method, recrystallization using an alcohol-based organic solvent such as isopropyl alcohol is generally known, but the purification effect of this method is still unsatisfactory, and moreover, it requires a large amount of solvent. Since it uses a harmful organic solvent, it is unfavorable in terms of the working environment and safety, and also in that it requires specific equipment.

The present inventor has long focused on the drawbacks of the above purification method and has continued research to develop an excellent purification method. They discovered that when hydrochloric acid was applied to dissolve in hot water and then cooled, only the hydrochloride of the target bis[4-(aminophenoxy)phenyl]sulfone in the crude product was selectively precipitated. The present invention has now been completed. That is, the present invention dissolves a crude bis[4-(aminophenoxy)phenyl]sulfone product under heating in water containing hydrogen chloride in a ratio of 1.0 to 5.0 moles per 1.0 mole of the sulfone, After filtering out insoluble impurities as necessary, bis[4-(aminophenoxy)phenyl] is cooled and precipitated.
The hydrochloride of the sulfone is filtered out, and the hydrochloride obtained in the string is heated and dissolved again in water. If necessary, insoluble impurities are filtered off, and then an aqueous alkali solution is added to neutralize and precipitate bis[4]. −
The present invention relates to a method for purifying bis(4-(aminophenoxy)phenyl)sulfone, which is characterized by separating (aminophenoxy)phenyl]sulfone.

The crude bis[4-(aminophenoxy)phenyl]sulfone product to be purified in the present invention includes crude products produced by various conventional production methods, and may vary depending on the production method. In addition to the target bis[4-(aminophenoxy)phenyl]sulfone, at least one of an aminophenol, a monoamine, and a coloring substance is contained.

In practicing the invention, the crude bis[4-(aminophenoxy)phenyl]sulfone product is dissolved in aqueous hydrochloric acid. The amount of hydrochloric acid at this time is usually 1.0 to 6 mol per 1.0 mol of bis[4-(aminophenoxy)phenyl]sulfone.
．． The crude product is approximately 0 mol, and the crude product is dissolved by heating. The heating temperature is not particularly limited to 4 degrees, but it is usually 50 to 100 degrees Celsius.
Preferably it is about 70 to 90°C. After dissolution, the solution is preferably cooled while stirring to separate the precipitated hydrochloride, and then dissolved again in warm water. The temperature at this time is also comparable to the temperature at which the crude product is dissolved. After dissolution, the filtrate is neutralized directly or after filtration by adding activated carbon as necessary. The neutralizing agent at this time is not particularly limited and can be appropriately selected from a wide range, such as caustic soda and caustic potash.

Examples include soda ash and ammonia water. After neutralization, cool and precipitate bis[4-(aminophenoxy)phenyl]
Filter off the sulfone and dry.

According to the method of the present invention, not only can bis[4-(aminophenoxy)phenyl]sulfone with a purity of 99% or more be obtained by an extremely simple operation, but it also does not require the use of large amounts of organic solvents. No underlying difficulties arise.

The present invention will be explained in detail by giving examples below.

Example 1 1, 4. j-bis(P-aminophenoxy)diphenylsulfone crude product 1,000y (2,82 mol) was added to 85
Dissolved in water 61 containing 582% concentrated hydrochloric acid (5.1 mol as hydrochloric acid) heated to 80°C, filtered off insoluble impurities at the same temperature, then cooled with stirring and boiled to 80°C to precipitate. The hydrochloride salt was separated. Further, this hydrochloride was dissolved in 60ml of water by heating to 80°C, 50ml of activated carbon was added, and after filtering at the same temperature, the filtrate was neutralized with 8% NaOH solution until the pH reached 6.5. After that, it is cooled and precipitated 4. Eibis (
P-aminophenoxy)diphenylsulfone was filtered off and dried.

Yield 810y, melting point 195.5-197.5℃, HP
LC purity 99.5%, Gardner hue 5. (Comparative crude product.

Melting point: 186.0-192.0°C, HPLC purity: 97.
5%, Gardner hue 20 or more) Example 2 4.4'-bis(m-aminophenoxy)diphenylsulfone crude product yield P! 805f,
Melting point 181.0-188.5℃, HPLC purity 99.2
%, Gardner Hue 4. (Comparative crude product.

Melting point 126.0-180.0℃, HPLC purity 97.0
%, Gardner hue 20 or more) (or more)

Claims (1)

[Claims] ■ Bis[4-(aminophenoxy)phenyl]sulfone crude product in an amount of 1.0 to 5.0% per 1.0 mole of the sulfone.
Dissolve with heating in water containing 0 mole of hydrogen chloride, filter out insoluble impurities as necessary, cool and filter out the precipitated bis[4-(aminophenoxy)phenyl]sulfone hydrochloride. , dissolve the hydrochloride obtained in the ore in water again by heating,
Bis[4-(aminophenoxy)], which is characterized in that after insoluble impurities are filtered out as necessary, the bis[4-(aminophenoxy)phenyl]sulfone that is precipitated is separated by neutralization by adding an aqueous alkali solution. Purification method of phenyl]sulfone.