JPH03284649A - 4-bromo-3,5,6-trifluorophthalonitrile and 4-bromo-3,5,6-trifluorophthalic acid and production of 4-bromo-3,5,6-trifluorophthalic acid and 3-bromo-2,4,5-trifluorobenzoic acid - Google Patents

Abstract

NEW MATERIAL:4-Bromo-3,5,6-trifluorophthalonitrile expressed by formula I and 4-bromo-3,5,6-trifluorophthalic acid expressed by formula II. USE:An intermediate raw material for functional polymer materials, medicines, agricultural chemicals and liquid crystal materials, etc. PREPARATION:Tetrafluorophthalonitrile is reacted with a metal bromide in an aprotic polar organic solvent, preferably sulfolane or N, N- dimethylformamide to stop the reaction when the rate of reaction attains 20-50%, preferably 25-45%. Thereby, the objective compound expressed by formula I is efficiently obtained. The resultant compound expressed by formula I is hydrolyzed in an aqueous solution of an inorganic acid (preferably sulfuric acid) to provided the compound expressed by formula II. Furthermore, the compound expressed by formula II is decarboxylated to readily afford 3- bromo-2,4,5-trifluorobenzoic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel compound 4-bromo 3.3 which is useful as an intermediate raw material for functional polymer materials, pharmaceuticals, agricultural chemicals, liquid crystal materials, etc.
Regarding 5.6-trifluorophthalonitrile.

The present invention also relates to a novel compound 4-bromo-3,5,6-trifluorophthalic acid and a method for producing the same, and further relates to a method for producing 3-bromo-2,4,5-trifluorobenzoic acid.

[Prior Art] 4-Bromo-3,5,6-trifluorophthalonitrile of the present invention is a "Chemical Abstract"
9, it is considered to be a new substance as far as the present inventors know.

However, “J, Chemical Sac, (Cl
”, Vol. 3, pp. 456-462 (1970),
When tetrafluorophthalonitrile is reacted in N-methylpyrrolidone with 4 or 8 times the molar amount of lithium bromide relative to the tetrafluorophthalonitrile at reflux temperature, tetrabromophthalonitrile and 4,5- It is disclosed that dibromo-3,6-lifluorophthalonitrile is formed in different proportions.

However, in this document, 4-bromo-3゜5,6-trifluorophthalonitrile (hereinafter referred to as F, Br
There is no description of the formation of PN (sometimes abbreviated as PN), and in fact, as long as the reaction was carried out under the conditions described in the literature, no formation of F or BrPN was observed.

In addition, 4-bromo-3,5,6-trifluorophthalic acid (hereinafter sometimes abbreviated as F, BrPA) is also
No description of this substance is found in ``Chemical Abstract'', etc.5, and as far as the present inventors know, it is considered to be a new substance.

The above 3-bromo-2,4,5-trifluorobenzoic acid (
Several methods are known for producing F, BrBA (hereinafter sometimes abbreviated as BrBA). For example, Japanese Patent Application Laid-Open No. 62-59263 discloses a production method using the following steps. There is.

However, in the method described in the above-mentioned publication, the manufacturing process is extremely long and the yield from the starting materials must be low, so that it is not satisfactory as an industrial manufacturing method.

[Problems to be solved by the invention] As mentioned above, the present inventors have developed a functional polymer material, a pharmaceutical,
F, BrP useful as intermediate raw materials for agricultural chemicals and liquid crystal materials, etc.
As a result of research to obtain N, we found that tetrafluorophthalonitrile (hereinafter sometimes abbreviated as F or PN),
When reacted with a metal bromide such as lithium bromide in an aprotic polar organic solvent such as sulfolane, the F4
By stopping the reaction when the reaction rate of PH reaches a certain value, or by adjusting the amount of metal bromide used with respect to F4PN, it is possible to efficiently generate the new compounds F and BrPN. .5-dibromo-
3,6-lifluorophthalonitrile (hereinafter referred to as F, Br,
We have discovered that by-products such as F, BrP, etc. can be suppressed to extremely small amounts.
A new compound F, BrPA, can be obtained by hydrolyzing N, and further.

The inventors discovered that F,BrBA can be produced by decarboxylating the F,BrPA, and completed the present invention.

[Means for Solving the Problems] The first object of the present invention is to provide a new compound, 4-bromo-3,5,6-trifluorophthalonitrile.

Moreover, the present invention is a novel compound! 114-bromo-3,5,6
- Trifluorophthalic acid and its production method, i.e. 4-
4-Bromo-3,5,6- characterized by hydrolyzing bromo-3,5,6-trifluorophthalonitrile
The purpose of this invention is to provide a method for producing trifluorophthalic acid.

Furthermore, the present invention provides a method for decarboxylating 4-bromo-3,5,6-trifluorophthalic acid.
45-) The object of the present invention is to provide a method for producing lifluorobenzoic acid.

The present invention will be explained in detail below.

In the present invention, first, the new compound F, BrPN, is efficiently produced by reacting F4PN with a metal bromide in an aprotic polar organic solvent (bromination step).

Examples of the aprotic polar organic solvent used in the second step include dimethylsulfoxide, diphenylsulfone, dimethylsulfone, sulfolane, N,N-dimethylformamide, N,N-dimethylacetamide, N
- methylpyrrolidone, acetonitrile, hexamethylphosphoric triamide, dialkyl ether of glycolic acid,
Among these aprotic polar organic solvents, sulfolane and N,N-dimethylformamide are preferably used from the viewpoint of good reactivity when used in the method of the present invention. These can be used alone or in combination of two or more. Also.

The aprotic polar organic solvent generally has a weight of 10% or less,
Preferably, it may contain up to 5 parts by weight of water.

The amount of the above aprotic polar organic solvent used is the starting material F4.
It is generally 100 to 3000 parts by weight, preferably 200 to 1000 parts by weight per 100 parts by weight of PN.

Examples of the metal bromide used in this step include lithium bromide and lithium bromide dihydrate.

Examples include alkali metal bromides such as sodium bromide, sodium bromide dihydrate, and potassium bromide, and hydrates thereof. The amount of metal bromide used is based on the starting material F.
It is generally 0.2 to 20 mol, preferably 0.5 to 10 mol, per 1 mol of 4PN.

This reaction step can be considered to proceed according to a first-order reaction formula.

(Note that Me represents a metal) As a preferred method for efficiently proceeding the reaction in this step and producing the novel compound F and BrPN of the present invention, first,
An example may be a method in which F, PN is reacted with a metal bromide in an aprotic polar organic solvent, and the reaction is interrupted when the reaction rate of F4PN reaches 20 to 5 oz, preferably 25 to 45%. .

The above reaction rate is determined by sampling a portion of the reaction solution at regular intervals from the start of the reaction and measuring the remaining amount of F4PN by gas chromatography (hereinafter sometimes abbreviated as GC).
It can be calculated from this value. If the reaction rate is too high, exceeding the above upper limit, the amount of by-products of F, Br, and PN will increase, which is undesirable.On the other hand, if the reaction rate is too small, below the above lower limit, the target products F and BrPN will be produced. The ratio is too small, and even if the solution containing the raw material F4PN after separation of F and BrPN is recycled, as will be described later, the productivity of F and BrPN will deteriorate, which is not preferable.

As mentioned above, the amount of metal bromide used in this first method is generally 0 to 1 mole of starting materials F and PN.
．． The amount is 2 to 20 mol, preferably 0.5 to 10 mol, but since it is not easy to separate and recover the metal bromide after the completion of this reaction step, when using an expensive metal bromide such as lithium bromide, It is particularly preferred that the amount used be 0.5 to 1.2 mol.

The reaction temperature in the bromination step of the present invention is generally 50 to
The temperature is 200°C, preferably 100-150°C, and the reaction time is generally 0.5-20 hours, preferably 1-10 hours.

After the bromination reaction by the first method is completed, the reaction solution usually contains
Since it contains the starting material F4PN, the target product F, B r P N, and small amounts of by-products F, Br, and PN, this reaction solution was cooled and then poured into water (the amount of water used is Generally 200 to 20 parts by weight per 100 parts by weight
F, PN, FllBrPN and
Separate 2Br and PN. The starting materials F and PN can be recycled.

In addition, the reaction solution was added to water, extracted using a water-insoluble organic solvent, the organic solvent layer was washed with water by a conventional method, concentrated to dryness, and then distilled under reduced pressure in the same manner as above to obtain F4PN, F, BrP.
It is also possible to separate N and F, Br2PN.

Here, [water-insoluble j] means that the solubility (weight) in water is 6 or less.

Examples of such water-insoluble organic solvents include aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, propylbenzene, cumene, butylbenzene, and cymene; halogenated aromatics such as paradichlorobenzene and baradifluorobenzene; For example, dialkyl ethers such as propyl ether and butyl ether; for example, aliphatic hydrocarbons of C or more such as n-hexane and n-hebutane; and the like.

In addition, as a second preferred method for efficiently advancing the reaction in this step, when reacting F4PN with the metal bromide in an aprotic polar organic solvent, the amount of the metal bromide used is adjusted to 1 mole of F4PN. This is a method in which the amount is 0.8 to 2 mol, preferably 0.9 to 1.5 mol. If the amount used is below the stated value, it is preferable because by-products such as F, Br, PN, etc. can be suppressed to a small amount, and if it is above the lower limit, a sufficient reaction rate can be obtained and a high level of reaction can be achieved. This is preferred because the reaction rate can be maintained.

In this method, unlike the first method, the fluorination reaction is preferably allowed to react until the starting material F4PN is substantially eliminated, without interrupting the fluorination reaction.

In this second method, as in the first method, the reaction temperature is generally 50 to 200°C, preferably ioo to 15°C.
The reaction time is generally 0.5 to 20 hours, preferably 1 to 10 hours.

After the bromination reaction in the second method, the reaction solution mainly contains the desired product FIIBrPN and byproducts F, Br, and P.
Since it contains N, this reaction solution is also treated in the same manner as in the first method, and F, BrPN and F are removed by vacuum distillation etc.
, Br, and PN can be separated.

In the present invention, F, Br obtained by the bromination step
PN and then 1 of an inorganic acid such as sulfuric acid, hydrochloric acid or hydrobromic acid (preferably sulfuric acid), e.g. 50 to 9
By hydrolyzing in a 0 weight 2 aqueous solution, a new compound F, BrPA, can be produced as shown in the following reaction formula (2).

(However, HX represents acid) The reaction temperature is generally about 100 to 180°C.

The obtained F, BrPA can be isolated and purified according to any known method6. For example, the water-insoluble organic solvent used in the bromination step is added to the cooled reaction solution after the completion of the hydrolysis reaction. Methods such as extracting the layer and drying it can be adopted.

In addition, when decarboxylating F, BrPA to obtain F, BrBA, a water-insoluble nitrogen-containing organic base having no N-H bond to be used in the decarboxylation step described later, or , the products F and BrPA obtained in the hydrolysis step are extracted using an aprotic polar organic solvent or a water-insoluble non-polar organic solvent, and the F, B
The first decarboxylation step is carried out by using the extract as it is without isolating rPA, or by adding other solvents and/or catalysts to be described later as necessary, to obtain the target product F and BrBA. can be manufactured.

lJJ [1 hill] In the present invention, the F and BrPA obtained in the above hydrolysis step are further heated in a solvent at a temperature range of 80 to 250°C to decarboxylate as shown in the following reaction formula (2). F, BrBA is easily produced.

The above solvent may be one that does not cause any unfavorable side reactions for this decarboxylation process between the starting material F, BrPA, reaction product F, BrBA and the catalyst used as necessary. As such a solvent, water, an aprotic polar organic solvent, a nitrogen-containing organic base having no N--H bond, and a mixture thereof can be suitably used.

In this specification, the term "polar organic solvent °" refers to a neutral organic compound having a permanent dipole moment of 2D (Debye) or more in its molecule.

Examples of the aprotic organic solvent include dimethylsulfoxide, diphenylsulfone, dimethylsulfone, tetramethylenesulfone (sulfolane), dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetonitrile, hexamethylphosphoric triamide, benzonitrile, Examples include nitrobenzene, dialkyl ether of glycolic acid, and quinoline.

Among these, examples of water-soluble aprotic polar organic solvents include dimethyl sulfoxide, dimethyl sulfone,
Tetramethylene sulfone (sulfolane), dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetonitrile, hexamethylphosphoric triamide,
Dialkyl ethers of glycolic acid [e.g., diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme),
Examples include tetraethylene glycol dimethyl ether (tetraglyme) and quinoline. Furthermore, examples of water-insoluble aprotic polar organic solvents include benzonitrile and nitrobenzene.

Examples of nitrogen-containing organic bases (hereinafter sometimes abbreviated as aprotic organic bases) that do not have the aforementioned N-)1 bond that can be used in the decarboxylation step of the present invention include -general formula % formula % Mention may be made of the tertiary amines represented.

Preferred among such tertiary amines are trialkylamines (e.g., trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, trilaurylamine, tristearylamine, dimethylethylamine, methyldiethylamine,
di-i-propylethylamine), trialkenylamines, dialkylarylamines (e.g. dimethylaniline, diethylaniline).

Alkyl diarylamines (e.g. diphenylmethylamine, diphenylethylamine), triarylamines (e.g. triphenylamine), dialkylcycloalkylamines (e.g. dimethylcyclohexylamine), N-alkyl substituted saturated nitrogen heterocyclic compounds (e.g. N -Methylpyrrolidine, N-methylmorpholine, N-
methylpiperidine) or quinuclidine.

Examples of other aprotic organic bases that can be used in the decarboxylation step include diamines represented by the general formula.

Such diamines include 1, for example, N,N'-tetraalkylalkylenediamine (e.g., N,N'-tetramethylmethylenediamine, N,N'-tetramethylethylenediamine, N,N'-tetramethyltrimethylenediamine). ), N,N'-tetraalkylarylenediamine (for example, N,N'-tetramethylphenylenediamine), or cyclic diamine (for example, triethylenediamine, N,N'-dimethylpiperidine).

Further examples of aprotic organic bases that can be used in the decarboxylation step include amidine represented by the general formula.

Examples of such amidines include trialkylamidines and bicyclic amidines (eg, diazabicycloundecene, diazabicyclononene).

The various solvents can be used alone or in combination with each other. For example, the aprotic organic base and water, the aprotic organic base and an aprotic polar organic solvent, or water and an aprotic polar organic solvent. They can be used in combination, such as polar organic solvents.

Furthermore, as the solvent used in the decarboxylation step, organic solvents other than those mentioned above can be used in combination, if necessary.

Suitable examples of such organic solvents include non-polar organic solvents. Note that the term "non-polar organic solvent" as used herein refers to a neutral organic compound having a permanent dipole moment within one molecule of less than 2D.

Such nonpolar organic solvents are preferably organic compounds with a boiling point of 80 to 300°C, such as aliphatic alcohols of 04 or higher such as butanol, hexanol, and cyclohexanol; for example, propyl ether, butyl ether, etc. , dialkyl ethers in which at least one alkyl group is C1 or more; for example, benzene, toluene, xylene, mesitylene.

Aromatic hydrocarbons such as ethylbenzene, propylbenzene, cumene, butylbenzene, and cymene; Halogen-substituted aromatic hydrocarbons such as paradichlorobenzene and baradifluorobenzene; For example, aliphatic carbons of 07 or more such as heptane and octane Hydrogens; for example, halogen-substituted aliphatic hydrocarbons such as 1.2-dichloroethane and 1.1.2.2-tetrachloroethane; and the like.

Among these non-polar organic solvents, aromatic hydrocarbons, halogen-substituted aromatic hydrocarbons, aliphatic hydrocarbons,
It is preferable to use a hydrocarbon solvent such as a halogen-substituted aliphatic hydrocarbon, and it is particularly preferable to use an aromatic hydrocarbon that is not substituted with a halogen atom.

The decarboxylation step can optionally be carried out in the presence of a catalyst. The catalyst may be appropriately selected from those known for this type of decarboxylation reaction, depending on the type of solvent used.

Catalysts that can be used in reactions in aqueous solvents include 1
For example, hydroxides, carbonates, sulfates, organic acid salts or fluorides of ammonia; hydroxides, carbonates, bicarbonates, sulfates, organic acid salts or fluorides of alkali metals; Examples include oxides, hydroxides, carbonates, sulfates, organic acid salts, or fluorides; sulfates, organic acid salts, or fluorides of organic bases; and the like.

The hydroxide, carbonate, sulfate, organic acid salt or fluoride of ammonia includes, for example, ammonium ammonia hydroxide, ammonium sulfate, ammonium fluoride, or a salt of 1 reaction raw material or product with ammonia, i.e. 4 Examples include ammonium -bromo-3,5,6-trifluorophthalate and ammonium 3-bromo-2,4,5-trifluorobenzoate.

Alkali metal hydroxides, carbonates, bicarbonates, sulfates,
Examples of organic acid salts or fluorides include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium sulfate, potassium sulfate, rubidium sulfate, cesium sulfate, sodium fluoride, and fluoride. Examples include potassium chloride, or a salt of a reaction raw material or product with an alkali metal (eg, sodium, potassium, rubidium, or cesium) hydroxide.

Alkaline earth metal oxides, hydroxides, carbonates, sulfates, organic acid salts or fluorides; examples of organic base sulfates, organic acid salts or fluorides include magnesium oxide, calcium oxide, strontium oxide , barium oxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium carbonate, calcium carbonate, barium carbonate, magnesium sulfate, calcium sulfate, strontium sulfate, calcium fluoride, or reaction raw materials or products. Examples include salts of alkaline earth metals (eg, magnesium, calcium, strontium or barium) with hydroxides.

Examples of sulfates, organic acid salts, or fluorides of organic bases include pyridine sulfates, quinoline sulfates, or sulfates of the aprotic organic bases, fluoride 1 reaction raw material F, and BrPA. Salt or product F, BrBA
An example is the salt of

Next, examples of the catalyst used in the solvent containing the aprotic polar organic solvent include the above-mentioned inorganic bases such as alkali metal hydroxides, carbonates, and bicarbonates.

Furthermore, in a solvent containing an aprotic organic base, the aprotic organic base itself has a catalytic action, and the aprotic organic base and the reaction raw material solution may optionally be included. Salts with certain sulfuric acids and salts with organic acids that are reaction raw materials or products also have catalytic activity, so it is not necessarily necessary to add a separate catalyst.

In the decarboxylation step of the present invention, depending on the catalyst used and optionally the type of catalyst used.

Heating conditions, the ratio of amounts of reaction raw materials to solvent, etc. can be easily set.

For example, when decarboxylation is carried out in an aprotic polar organic solvent, the reaction temperature is 80 to 200°C, preferably 90°C.
~180°C, particularly preferably 0.5 at 105-140°C
The heat treatment is preferably carried out under atmospheric pressure for ~3 hours, preferably about 1 hour, and the amount of catalyst is 0.0 per mole of 1 reaction material.
The amount is preferably in the range of 5 to 0.75 mol, preferably 0.2 to 0.5 mol.

When decarboxylation is carried out in an aprotic organic base solvent, the reaction temperature is 100 to 200°C, preferably 120 to 180°C for 0.5 to 50 hours, preferably about 0.5 to 200°C. It is preferable to heat the treatment under atmospheric pressure for 5 hours. If the treatment is carried out in the coexistence of a non-polar organic solvent, the organic base is generally 0.1 to 3 mol per 1 mol of one reaction material (from the viewpoint of reaction rate). 0.3 to 2 mol, preferably 0.3 to 2 mol.

More preferably more than 0.75 to 1.5 mol) and 0.2 to 10 mol (preferably 0.5 to 5 mol) of a non-polar organic solvent are used. If non-polar organic solvents are not used,
The organic base is preferably used in an amount of 0.5 to 10 mol, more preferably 0.5 to 5 mol, per mol of the reaction raw material.

Furthermore, when decarboxylation is carried out in an aqueous solvent, the reaction temperature is 80 to 250°C, preferably 100 to 220°C, particularly preferably 130 to 180°C, for 2 to 40 hours, preferably about 5 to 30 hours, pH 0.7-2.2. The aqueous solvent is preferably 1.2 to 2.0, and the heat treatment is preferably carried out under vacuum to about 15 atm, preferably 1 to 10 atm. The amount of the aqueous solvent used is 0.1 per mole of the reaction raw material. -2 mol, preferably 0.2-1 mol. The amount of catalyst used varies depending on the type of catalyst, and for each mole of 1 reaction raw material, the amount of ammonia, alkali metal, alkaline earth metal, or organic base sulfate or fluoride is 0.01 to 0.01.
3 mol, preferably 0.05-1 mol; 0 for organic bases
．． 01-1.2 mol, preferably 0.1-0.9 mol;
0.01 to 0.4 mol, preferably 0.05 to 0.4 mol for ammonia hydroxide, carbonate or organic acid salt, alkaline earth metal oxide, hydroxide, carbonate or organic acid salt
0.25 mol, 0.002 to 0.1 mol for alkali metal hydroxide, carbonate or organic acid salt, preferably 0
．． 005 to 0.05 mol.

The obtained target product F, BrBA, can be isolated and purified according to any known method. When using non-aqueous solvents such as non-polar organic solvents.

After the completion of the decarboxylation reaction, an aqueous solution of an alkaline compound such as an aqueous sodium hydroxide solution is added to the cooled reaction solution, and the mixture is stirred.
A method can be adopted in which the aqueous layer is separated by liquid separation, then an aqueous solution of an inorganic acid such as an aqueous hydrochloric acid solution is added to the aqueous layer, and the precipitated crystals are filtered and dried.

In addition, as mentioned above, the product F in the hydrolysis step,
Without isolating BrPA, the F and BrPA are extracted using a water-insoluble aprotic organic base, a water-insoluble aprotic polar organic solvent, and a water-insoluble non-polar organic solvent. If necessary, a water-insoluble or water-soluble aprotic organic base, an aprotic polar organic solvent, a nonpolar organic solvent, and/or the above-mentioned catalyst may be further added to carry out the decarboxylation step continuously. can.

Examples of such water-insoluble aprotic organic bases include trialkylamines (each alkyl group has 2 or more carbon atoms), dialkylarylamines, alkyldiarylamines, triarylamines, and dialkylcycloalkylamines. and diamines such as N,N'-tetraalkylarylene diamine; Examples of water-insoluble aprotic polar organic solvents include benzonitrile and nitrobenzene; Examples of solvents include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, propylbenzene, cumene, butylbenzene, and cymene; halogen-substituted aromatic hydrocarbons such as paradichlorobenzene and paradifluorobenzene. For example, aliphatic hydrocarbons of 0.07 or higher such as heptane and octane; For example, dialkyl ethers such as propyl ether and butyl ether.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Reference Examples.

Example 1 Tetrafluorophthalonitrile (F4
PN) 50g (purity: about 98% by weight, about 0.245 mol), 17.2g of lithium bromide (99% purity, about 0.196 mol), and 150g of sulfolane were reacted at about 110°C. .

The residual amount of F4PN in the reaction solution was measured every 30 minutes after the start of the reaction using gas chromatography (GCI), and the reaction rate of F4PN was calculated. After 3 hours of reaction, the reaction rate was 45%.
W, the remaining amount of F4PN is 55. Ox,
Target product 4-bromo-3,5,6-trifluorophthalonitrile (F, BrPN) 44.0χ and by-product 4
,5-dibromo-3,5,6-trifluorophthalonitrile (F, Br, PN) 1.0 χ], the reaction was stopped and the reaction solution was cooled to room temperature (20°C). The reaction solution was added to about 300 ml of distilled water and mixed. The produced crystals are separated by suction filtration, dried, and fractionated under reduced pressure of about 25 Torr to obtain the desired product F.
, BrPN 26. Og (purity 98.4 weight 2, yield 4011, and starting material F4PN 25.0 g
(Purity 98.0 weight 2, raw material recovery rate 50χ) was obtained. The physical property values of the obtained F and BrPN are as follows.

Melting point: 114-115°C Mass, X/(cuttle (fJ): m/z-260"F-
NMR: (CDCI, solvent, CF, COOH internal standard, 1H-decoupling) (ppm) δ-23,6 (IF, dd, J=6.10
Hz, 10.99) 1z) -37,9 (IF, dd,
J=6.10Hz, 21.97Hz)-53,6(IF
, dd, J = 10.99 Hz, 21.971 (z) Example 2 In Example 1, the amount of lithium bromide used was 25.8 g.
(purity of about 99% by weight, about 0.294 mol), and the reaction was carried out in the same manner except that the remaining amount of F4PN in the reaction solution was not measured by GC during the course of the reaction and the reaction was carried out for 7 hours.

When the obtained reaction solution was analyzed by GC, the target product F,
It contained 82χ of BrPN and 14χ of byproducts F, Br, and PN.

Thereafter, by treating in the same manner as in Example 1, 48.7 g of the target product F, BrPN (purity of about 98.5% by weight, yield 75χ) and 9.6 g of by-products F, Br, PN (purity of about 98%) were obtained. .5% by weight, yield 12z) was obtained.

Comparative Example 1 F4P was placed in a 50m1 eggplant-shaped flask equipped with a reflux condenser.
N5.0g (approximately 25 mmol), lithium bromide8.
1 g (purity: approx. 99 weight 2. approx. 92.5 mmol) and 30 g of N-methylpyrrolidone were charged at reflux temperature (approx.
GC analysis of one reaction solution reacted for 20 minutes at 02℃) revealed that the raw material F4PN and the target products F and BrPN were not present, and byproducts F, Br, PN, and tetrabromophthalonitrile (Br4PN) were present. Only 2 each
Obtained in a yield of 1z and 54χ.

Example 3 Into the same apparatus as in Example 1, 50 g of F, BrPN (purity 98 weight 2, about 0.245 mol) and 73.6 g (0,563 mol) of 75 weight 2 sulfuric acid aqueous solution were charged, and about 1
After the hydrolysis reaction was completed at 50°C for 2 hours, 100g of distilled water was added to the reaction solution and the chamber was heated! (20°C), then extracted twice with 50 g of ether, and dried the extract to obtain 56.8 g of F, BrPA (purity 98.0% by weight, yield 99.1% based on F, BrPN).
) was obtained. The physical properties of the obtained F and BrPA were as follows.

Melting point: 160-161°C Mass spectrum (EI): m/z=2981-NM
R: (CDCI, solvent, CF, C0OH internal standard, t
H-decoupling) (ppm) δ-33,3 (IP, dd, J=2.44
Hz, 13.43Hz)-46,5(IP, dd, J
'2.44Hz, 21.97Hz) - 63,8 (IP,
dd, J=13.43Hz, 21.97Hz)
Example 4 F, 50 g of BrPA (purity of about 98% by weight, about 0.164 mol) and 58 g of tri-n-octylamine (0,164 mol) were charged into the same apparatus as in Example 1, and about 13
After the decarboxylation reaction was completed for 1 hour at 0°C, the reaction solution was poured into the room! (20°C), then add 78.7 g (0,197 mol) of a 10 wt. aqueous sodium dihydroxide solution, stir and mix well, separate the layers, take out the aqueous layer, and add 35 wt.% hydrochloric acid to this aqueous solution. 30.8g (0.30 mol)
was added for salting out, and the precipitated crystals were filtered off. By drying the obtained crystals, 38.4 g of F, BrBA (
Purity 98.0 Yield based on weight Z, F, BrPA 90.
0χ) was obtained. The physical properties of the obtained F and BrBA were as follows.

Melting point: 106-107°C Mass spectrum (EI): m/z=254”F-NM
R: (CDCl solvent, CF, C0OH internal standard, -H
-decoupling) (ppm) δ--28,9 (IF, dd, J-4,8
9Hz, 14.64) 1z) -44,6 (IP, d-d
, J=4.89Hz, 21.97Hz)-28,9(I
F, dd, J = 14.64Hz, 21.97Hz) Example 5 Distilled water was added to the reaction solution obtained by carrying out the reaction in the same manner as in Example 3.
After adding 0g and cooling to room temperature (20℃),
Extraction was performed by adding 86.6 g (0,245 mol) of octylamine to obtain 167 g of an extract. Approximately 5 weights of this extract was added to 412 g of 2-sodium bicarbonate aqueous solution (0.24 g
F, BrBA 55.9
(purity 98.1% by weight, yield 87.7χ based on F and BrPN) was obtained.

Claims (4)

[Claims] (1) 4-bromo-3,5,6-trifluorophthalonitrile. (2) 4-bromo-3,5,6-trifluorophthalic acid. (3) 4-bromo-3 characterized by hydrolyzing 4-bromo-3,5,6-trifluorophthalonitrile
, 5,6-trifluorophthalic acid production method. (4) 3-bromo-2,4,5 characterized by decarboxylating 4-bromo-3,5,6-trifluorophthalic acid
-Process for producing trifluorobenzoic acid.