JPS5932462B2 - Production method of bis(thioetherphthalimide) - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention describes the preparation of N-substituted phthalimides into bis(thioether phthalimide) and bis(thioether phthalic anhydride).
and the products obtained by such a method.

Some of the compounds provided by the present invention have the formula <:□
・Group:>・(I) Includes bis(thioether phthalic anhydride) represented by:

These compounds can be used as antioxidants for various organic materials (eg, rubber, hydrocarbon oil, polypropylene, etc.), curing agents for epoxy resins, intermediates for polyester resins, and the like. According to the present invention, (1
) where M is an ion of an alkali metal such as sodium, potassium and lithium; 20) 1 selected from aromatic groups
a valent group, and X is a fluorine atom, a chlorine atom, a bromine atom,
(a group selected from iodine atoms and nitro groups)
(2) to form an intermediate N-substituted bis(thioether phthalimide) of the formula (where R is as defined above); (thioether phthalimide) is hydrolyzed in the presence of a base to give the corresponding bis(
(3) acidifying the bis(thioether phthalate) to recover the corresponding bis(thioether phthalate), and then (4) dehydrating the bis(thioether phthalate). Also provided is a process for preparing a compound of formula (1), which comprises converting the compound into the corresponding bis(thioether phthalic anhydride).

Examples of the group represented by R in the above formula include methyl group, ethyl group, propyl group, butyl group, pentyl group, phenyl group, tolyl group, xylyl group, naphthyl group, chlorophenyl group, bromotril group, etc. can be mentioned.

As the bis(thioether phthalic anhydride) of formula (1), for example, bis(2,3-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride , 2,3-dicarboxyphenyl-3',4'-dicarboxyphenyl sulfide dianhydride, and the like.

Examples of the N-substituted bis(thioetherphthalimide) of formula () include 3,31-bis(N-phenylphthalimide) sulfide, 4,4'-bis(N-phenylphthalimide) sulfide, 3,3'- Examples include bis(N-butylphthalimide) sulfide, 4,4'-bis(N-methylphthalimide) sulfide, and 3,41-bis(N-phenylphthalimide) sulfide.

These bis(thioetherphthalimides) can be used as plasticizers, flame retardants, or antioxidants for organic polymers such as polyvinyl chloride, polyimides, aromatic hydrocarbons, and the like. N-substituted phthalimides of formula () include an organic amine of formula (wherein R is as defined above) and an organic amine of formula (wherein R is as defined above) and an organic amine of formula (wherein R is as defined above) It can be prepared by reacting substantially equimolar amounts of substituted phthalic anhydride.

Organic amines represented by the formula RNH2 include, for example, aniline, toluidine, and the like, as well as methylamine, ethylamine, and the like. Alkali metal sulfides, such as sodium sulfide, are in a hydrated state (Na2S・9H
20) Alternatively, it can be used in an anhydrous state.

Anhydrous sodium sulfide can be obtained by azeotropically removing the water of hydration from the salt, by heating the salt under vacuum to temperatures up to about 400°C to remove the water of hydration, or by using commercially available You can purchase items. In practicing the present invention, N-substituted bis(thioetherphthalimide) of formula () is produced by reacting an alkali metal sulfide with an N-substituted 7-thalimide of formula ().

The bis(thioetherphthalimide) is then hydrolyzed and converted to bis(thioetherphthalate), and then the bis(thioetherphthalate) is acidified. If the bis(thioether phthalic acid) thus obtained is dehydrated, the bis(thioether phthalic anhydride) of formula (1) will be produced. N-substituted bis(
The step of producing thioetherphthalimide may be carried out at a temperature of 25 to 150° C. using a dipolar neutral solvent such as dimethylformamide, dimethylsulfoxide, hexamethylphosphoric triamide, dimethylacetamide, etc.

Mixtures of such dipolar neutral solvents with nonpolar solvents (eg toluene, chlorobenzene, dichlorobenzene, etc.) can also be used. Furthermore, phosphonium salts can also be used with non-polar solvents. The reaction time depends on the temperature,
Depending on the degree of stirring, etc., the time can range from 5 minutes to 16 hours or more. From the mixture thus obtained, N-substituted bis(
To recover the thioether phthalimide, the mixture can be filtered and the filtrate treated with a water-acid mixture, such as dilute hydrochloric acid.

The step of hydrolyzing such N-substituted bis(thioether phthalimide) to produce bis(thioether Jalate) is carried out by adding a refluxing aqueous base solution, such as a 10 to 50% alkali hydroxide (e.g., sodium hydroxide) aqueous solution. This may be carried out by contacting with N-substituted bis(thioetherphthalimide).

Other bases that can be used include potassium hydroxide, magnesium hydroxide, and the like. The time for hydrolysis of the N-substituted bis(thioetherphthalimide) to be accomplished can range from less than 1 hour to more than 48 hours, depending on the type of reactants, degree of agitation, temperature, etc. It should be noted that organic amine by-products can be removed by standard techniques such as steam distillation. Furthermore, the rate of hydrolysis is greatly accelerated if the reaction is carried out at temperatures within the range of 150-200°C and pressures above atmospheric. The N-substituted bis(thioetherphthalimide) hydrolysis product is then acidified with a mineral acid such as dilute hydrochloric acid. The bis(thioetherphthalic acid) thus obtained can be dehydrated at temperatures within the range of 100 to 200°C by use of a dehydrating agent such as acetic anhydride, acetyl chloride, synchlohexylcarbodiimide, and the like. Recovery and purification of the final product may be accomplished by standard techniques. Examples are presented below to enable those skilled in the art to better practice the invention. Example
1 1 part anhydrous sodium sulfide, 6.85 parts 3-nitro-N-phenylphthalimide and about 6 parts dimethylformamide
A mixture of 6 parts was stirred at room temperature for 1 hour under a nitrogen atmosphere.

The solution was heated at 70°C for 2 hours and then cooled to room temperature. After filtration, the filtrate was added into acidic water. The resulting precipitate was collected and dried, yielding 5.3 parts (95% yield) of 3.3'bis(N-phenylphthalimide) sulfide. Further recrystallization from toluene yielded a sample with a melting point of 248-250°C. The identity of the product was confirmed by infrared and mass spectrometry and 13C spectra. A blend of about 2 parts of the bis(phthalimide) sulfide described above and about 100 parts of an aromatic hydrocarbon lubricating grease was prepared.

It has been found that such greases have improved antioxidant properties. Example 2 1 part anhydrous sodium sulfide, 6.85 parts 4-nitro-N-phenylphthalimide and about 6 parts dimethylformamide
A mixture of 6 parts was heated at 70°C under a nitrogen atmosphere to
- heated for hours.

The solution was cooled to room temperature. The resulting precipitate was collected, washed with dimethylformamide and water, and dried, yielding 3.5 parts (56% yield) of 4·l-
Bis(N-phenylphthalimide) sulfide was obtained. Further recrystallization from o-dichlorobenzene gave a sample with a melting point of 293-295°C. The identity of the product was confirmed by infrared, infrared and mass spectrometry and 13C spectroscopy. Example 3 1 part anhydrous sodium sulfide, 6.6 parts 3-chloro-N-phenylphthalimide and about 40 parts dimethylformamide
1 part at 100°C under nitrogen atmosphere.
Stirred for 6 hours.

The solution was cooled to room temperature. After filtration, the filtrate is 500
1.2 parts of NHC. The resulting precipitate was filtered and dried, and as in Example 1, 5.7 parts (yield: 90%) of 3,3'-bis(N-phenylphthalimide) sulfide was obtained. Example 4 1 part anhydrous sodium sulfide, 6.6 parts 4-chloro-N-phenylphthalimide and about 50 parts dimethylformamide
1 part at 100°C under nitrogen atmosphere.
Stirred for 6 hours.

The solution was cooled to room temperature. The precipitate thus formed was collected by filtration, washed with dimethylformamide,
After drying, 6.
Two parts (95% yield) of 4.4'-bis(N-phenylphthalimide) sulfide were obtained. Example 5 A mixture consisting of 1 part of anhydrous sodium sulfide, 6.35 parts of 3-nitro-N-butylphthalimide, and about 90 parts of anhydrous dimethylformamide was heated at 70<0>C for 2 hours under a nitrogen atmosphere.

The mixture after cooling was added to 500 parts of 1.2N HCl. The resulting yellow precipitate was collected and dried to yield 4.7 parts (85% yield) of 3,3'-bis(N-butylphthalimide) with a melting point of 123-125°C.
Sulfide was recovered. The body of such products is in the infrared spectrum as well as carbon and protons? Confirmed by spectrum. Example 6 3,3'-bis(N
- phenyl phthalimide) sulfide 1 part and 50%
A mixture consisting of 1 part of aqueous sodium hydroxide solution was heated to 176°C.
The mixture was stirred for 3 hours.

The solution was cooled and then thoroughly extracted with ether. The aqueous layer was added to 20 parts of acidic water. The resulting precipitate was collected and dried, yielding 0.53 parts of bis(2,3-dicarboxyphenyl) sulfide. The identity of the product was confirmed by infrared and NMR spectra. A mixture consisting of 0.53 parts of the above crude acid, 25 parts of glacial acetic acid and about 1 part of acetic anhydride was refluxed for 4 hours.

such solution is concentrated by removal of about 20 parts of acetic acid;
It was then cooled to room temperature. The precipitate thus formed was collected and dried to give 0.5 part (75% yield based on bis(phthalimide) sulfide) of a yellow powder with a melting point of 240-242°C. Based on the method of preparation and infrared, NMR and mass spectra, the product was bis(2,3-dicarboxyphenyl)sulfide dianhydride. The above screws (2, 3-
dicarboxyphenyl) sulfide dianhydride 10
1 part was blended with 100 parts of liquid epoxy resin NOvOlak having an epoxide equivalent weight of about 178. It has been found that such formulations cure after a few hours at ambient temperatures. Example 7 A mixture consisting of 1 part of 4,4'-bis(N-phenylphthalimide) sulfide and 1 part of 50% aqueous sodium hydroxide solution was stirred at 176°C (135 psi) for 31 hours.

The solution was cooled and then thoroughly extracted with ether. The aqueous layer was added to 20 parts of acidic water. When the precipitate thus formed was dried, 0.54 parts of bis(3
-4-dicarboxyphenyl) sulfide was obtained.
The identity of the product was confirmed by infrared and spectroscopy. A mixture consisting of 0.54 parts of the above crude acid, 35 parts of glacial acetic acid and about 1 part of acetic anhydride was refluxed for 4 hours.

The solution is concentrated by removing about 30 parts of acetic acid;
It was then cooled to room temperature. The precipitate thus formed was collected and dried to give 0.5 parts (75% yield based on bis(phthalimide) sulfide) of a white powder with a melting point of 202-203°C.

Based on the method of preparation and infrared, x, and mass spectra, the product was bis(3,4-dicarboxyphenyl)sulfide dianhydride. Example 8 A mixture consisting of 1 part of 3.3'-bis(N=phenylphthalimide) sulfide, 25 parts of 50% aqueous sodium hydroxide solution and 25 parts of distilled water was heated under reflux for 6 hours.

The solution was cooled to room temperature, extracted with ether, and the aqueous layer was acidified. The acidic aqueous layer is thoroughly extracted with ether, the ether extract is washed with saturated salt solution,
It was then dried over anhydrous magnesium sulfate. After removing the drying agent, the solution was concentrated to give a tan solid. Based on the infrared spectrum, the product was the same as the acid obtained in Example 6. Dehydration of the crude acid by refluxing with acetic anhydride and glacial acetic acid as in Example 6 gave a tan solid.

Furthermore, when recrystallized from toluene, 231-234
A sample with a melting point of °C was obtained. Based on infrared, M and mass spectra, the product was bis(2,3-dicarboxyphenyl)sulfide dianhydride as in Example 6. Note that the above examples are based on bis(
It should be understood that only a small portion of the formula (thioether phthalic anhydride) and bis(thioether phthalimide) of formula () are mentioned.

Next, the embodiments of the present invention are listed below.

1. the alkali metal sulfide is sodium sulfide;
A method according to the claims.

2. A method according to the preceding claims, wherein said N-substituted phthalimide is N-phenyl-3-chlorophthalimide. 3. A method according to the preceding claims, wherein said N-substituted phthalimide is N-phenyl-3-nitrophthalimide.

4. A method according to the preceding claims, wherein said N-substituted phthalimide is N-phenyl-4-chlorophthalimide.

5. A method according to the preceding claims, wherein the N-substituted phthalimide is N-phenyl-4-nitrophthalimide.

6. A method according to the preceding claims, wherein said N-substituted phthalimide is N-butyl-3-nitrophthalimide.

7. Formula (where R is a C(1-8) alkyl group and a C(6-8)
20) Bis(phthalimide) sulfide, which is a monovalent group selected from aromatic groups.

8.3.3'-bis(N-phenylphthalimide) sulfide.

9.4.4'-bis(N-phenylphthalimide) sulfide.

10.3.3'-bis(N-butylphthalimide) sulfide.

11. formula anhydride represented by.

12. Bis(2,3=dicarboxyphenyl)sulfide dianhydride.

13. Bis(3,4-dicarboxyphenyl)sulfide dianhydride.

Claims (1)

[Claims] 1 Alkali metal sulfide represented by the formula M_2S (where M is an alkali metal ion) and the formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (where R is a lower alkyl group) and a monovalent group selected from phenyl groups, and X is a group selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and nitro groups). A method for producing N-substituted bis(thioether phthalimide) represented by the formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (where R is as defined above).