JPH02282378A - Production of acid anhydride - Google Patents

Abstract

PURPOSE:To advantageously obtain the title compound useful as an industrial raw material at one stage without problems of decomposition of raw material compound and isomerization by reacting a polycarboxylic acid ester as a raw material with a compound such as trimethylsilane iodide. CONSTITUTION:A compound having a structure shown by formula I (R<1> and R<2> may be the same or different and are monofunctional organic group) as a raw material is reacted with (1) a compound shown by formula II (R<3>, R<4> and R<5> are monofunctional organic group) or (2) a mixture of a compound shown by formula III (X is Cl or Br) and a compound shown by formula MI (Ma is alkali metal) in acetonitrile as a solvent at 0-100 deg.C to give the aimed compound. A dialkyl ester of dicarboxylic acid such as succinic acid or tetraalkyl ester of tetracarboxylic acid such as cyclobutanetetracarboxylic acid may be cited as the concrete example of the compound shown by formula I, methylsilane as the compound shown by formula II and trimethylsilane chloride as the compound shown by formula III. The amount of the compound shown by formula II is 3-5 mols based on 1 mol compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for producing acid anhydrides, which are important for use as industrial raw materials.

[Prior Art] Generally, the method for producing acid anhydrides from polycarboxylic esters is a two-step method in which the carboxylic esters are first hydrolyzed to form polycarboxylic acids and then converted to acid anhydrides. It is being done.

The hydrolysis method in this two-step method includes ■water,
In solutions such as methanol, ethanol, and acetic acid, hydrochloric acid,
Acid hydrolysis method, in which sulfuric acid, hydrobromic acid, etc., and carboxylic acid ester are reacted at room temperature or above, ■ Sodium hydroxide, potassium hydroxide, etc. and polycarboxylic ester are reacted in a solution of water, methanol, ethanol, etc. A base hydrolysis method in which the reaction is carried out at room temperature or higher is known.

Furthermore, known methods for converting polycarboxylic acids into acid anhydrides include a heating method and a chemical method using a dehydrating agent such as acetic anhydride.

[Problems to be Solved by the Invention] However, the two-step method for producing acid anhydrides described above has a problem in that it involves decomposition and isomerization of the raw material compound.

[Means for Solving the Problems] That is, the present invention provides a compound having a structure represented by C-C0OR+ (where R1 and R2 may be the same or different and represent a -valent organic group), ( 1) Compound represented by R3R4R5SiI (where R3, R4 and R5 may be the same or different, -
or (2) a compound represented by R3R4R5SiX (where R3, R4 and R5 are the same as above, and X represents a chlorine atom or a bromine atom, and the following Provided is a method for producing an acid anhydride, which is characterized by reacting a mixture of a compound (referred to as "compound ■") and a compound represented by MI (herein, M represents an alkali metal atom, hereinafter referred to as "compound IfJ"). It is something.

In the structure represented by C-C○ORI formula % formula % which the polycarboxylic acid ester has, monovalent organic groups which are R+ and R2 include, for example, alkyl groups such as methyl group, ethyl group, propyl group, butyl group, etc. Among these, an alkyl group having 1 to 5 carbon atoms is preferred.

Examples of polycarboxylic acid esters include cobalic acid, itaconic acid, malic acid, tartaric acid, oxalpropionic acid,
Cyclopropane-1,2-dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid, phthalic acid, 4-hydroxyphthalic acid, 4, 5-dihydroxyphthalic acid, 2,3-naphthalene dicarboxylic acid, 3
Dialkyl esters of dicarboxylic acids such as 4-furandicarboxylic acid, and 1,2,3,4-cyclobutanetetracarboxylic acid, 1. 2. 3.4-cyclopentanetetracarboxylic acid, norbornene-2,3,5,6-tetracarboxylic acid, pyromellitic acid, 3.3', 4.4
' -benzophenonetetracarboxylic acid, 3.3'
, 4,4'-biphenyltetracarboxylic acid and other tetraalkyl esters of tetracarboxylic acids.

In compound I, the monovalent organic groups R3, R4, and R5 include the same groups as R1 and R2, and specific examples of compound I include trimethylsilane iodide, triethylsilane iodide, , isopropyldimethylsilane iodide, t-butyldimethylsilane iodide, and the like.

In compound (1), the monovalent organic groups R3, R4, and R5 include the same groups as R1 and R2, and specific examples of compound H include trimethylsilane chloride, triethylsilane chloride, and triethylsilane chloride. Examples include isopropyldimethylsilane, chlorinated t-butyldimethylsilane, bromide trimethylsilane, bromide triethylsilane, bromide isopropyldimethylsilane, bromide t-butyldimethylsilane, and the like.

In compound (■), examples of the alkali metal M include lithium, sodium, potassium, rubidium, cesium, etc., and specific examples of compound (■) are:
Lithium iodide, sodium iodide, potassium iodide,
Examples include rubidium iodide and cesium iodide.

It is preferable to use a solvent for the reaction between the polycarboxylic acid ester and Compound I or the mixture of Compound (1) and Compound (2).

Here, the solvent is an organic solvent that does not react with Compound I, Compound (1), and Compound (2), and is preferably acetonitrile, carbon tetrachloride, chloroform, dichloromethane,
sulfolane, etc., and more preferably the amount of compound (2) used in the acetonitrile reaction is 1 per equivalent of the group represented by the formula -COORI in the polycarboxylic acid ester.
The amount is more than 1 mole, preferably 3 to 5 moles. Further, the mixing ratio of compound (1) and compound (2) is arbitrary, but preferably 1:1, and the amount of compound (1) and compound (2) required for the reaction is per equivalent of the group represented by the formula -COORI possessed by the polycarboxylic acid ester. Each amount is 1 mol or more, preferably 3 to 5 mols each.

In addition, the reaction temperature is 0 to 100°C, and the reaction time is 1 hour to 5.
It is about the size of a snake.

After the reaction is completed, the acid anhydride obtained is usually extracted using ether, ethyl acetate, dichloromethane, chloroform, etc., washed, and then dried.

[Examples] The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the Examples.

Example 1 Succinic acid dimethyl ester2. Olg (13.

Add 10.8 mmol of trimethylsilane iodide to a solution of 20 ml of carbon tetrachloride at room temperature. 5m1.
(82.

7 mmol) was added dropwise and heated at 50° C. for 10 hours.

After the reaction was completed, 100 ml of water was added, and the reaction product was extracted with 100 ml of chloroform using a separating funnel.

The extracted organic layer was first washed with 50 ml each of water, then 10% by weight sodium thiosulfate solution, and then saturated brine, dried over 10 g of anhydrous sulfur and lithium sulfate, and then the solvent was distilled off under reduced pressure using an evaporator. , succinic anhydride 1. 0
8 g (10.8 mmol) was obtained.

Example 2 Succinic acid dimethyl ester 2.05g (14.

On+mol) and sodium iodide 12.6g (84
.

1 mmol) in 25 ml of acetonitrile,
To this was added 10% trimethylsilane chloride at room temperature. 8ml (
85, 1 mmol) was added dropwise, and heating and refluxing was continued for 4 days under normal pressure. After the reaction was completed, 100 ml of water was added and the reaction product was extracted with 100 ml of ether, washed and dried in the same manner as in Example 1 to obtain succinic anhydride 1.
．． 13 g (11.3 mmol) was obtained.

Example 3 2.05 g of phthalic acid dimethyl ester (10.

6 mmol) and 9.50 g of sodium iodide (63.

4 mmol) was suspended in 25 ml of acetonitrile, and 8.0 mmol of trimethylsilane chloride was suspended at room temperature. Oml (6
3.

After dropping 0 mmol), heating under reflux was continued for 4 days.

After the reaction is complete, add 100ml of water and add 100ml of ether.
The reaction product was extracted, and the following procedure was performed in the same manner as in Example 1.
Wash and dry to remove 1.53 g of phthalic anhydride (10.
3 mmol) was obtained.

Example 4 Dimethyl 4-t-butyldimethylsiloxyphthalate 0.
33 g (1.0 mmol) and 0.91 g (6.1 mmol) of thorium iodide were suspended in 10 ml of acetonitrile, and 0.9 g (6.1 mmol) of thorium iodide was added to the suspension at room temperature. 80ml (6.:3mmol
) was added dropwise, and heating and refluxing was continued for 4 days. After the reaction, 100 ml of water was added and the reaction product was extracted with 100 ml of ether, washed and dried in the same manner as in Example 1 to obtain 0.27 g of 1-t-butyldimethylsiloxyphthalic anhydride ( 0.97 north of) was obtained.

Example 5 3, 9 2, 10 4.8 [9. 2. 1. 1, 0, 0
] ] tricyclopentadecyl 5,12 diene 5
．． 26 g (16.6 mmol) and 15.0 g (0.10 mmol) of sodium iodide were suspended in 20 ml of acetonitrile, and trimethylsilane chloride 15 was added to the suspension at room temperature.

Oml (0.1 18 mmol) was added dropwise and heating under reflux was continued for 5 days. After the reaction was completed, 100 ml of water was added and the reaction product was extracted with 100 ml of ether, followed by washing and drying in the same manner as in Example 1 [9. 2.

3,9 2,10 4.8 1,1 ,0 ,0 ] ] Tricyclopentadecyl 5,12 diene anhydride 3. 54g (13
, 1 mmol) was obtained.

[Effects of the Invention] According to the present invention, an acid anhydride can be produced from a polycarboxylic acid ester through a stepwise reaction without decomposition or isomerization of the raw material compound.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] Having a structure represented by the formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (where R^1 and R^2 may be the same or different and represent a monovalent organic group) (1) A compound represented by R^3R^4R^5SiI (
Here, R^3, R^4 and R^5 may be the same or different and represent a monovalent organic group) or (2) a compound represented by R^3R^4R^5SiX (
Here, R^3, R^4 and R^5 are the same as above, and X represents a chlorine atom or a bromine atom) and a compound represented by MI (here, M represents an alkali metal atom). A method for producing an acid anhydride, characterized by reacting it with a mixture of.