JPH0681737B2 - Process for producing 4- (parafluorobenzoyl) phenol - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing 4- (parafluorobenzoyl) phenols, which are important as monomers for heat-resistant polymers or intermediates for agricultural chemicals, pharmaceuticals and the like.

(Prior Art and Problems) As a method for producing 4- (parafluorobenzoyl) phenol, a method of reacting parafluorobenzoic acid and phenol in a large amount of polyphosphoric acid (Japanese Patent Publication No. 50-4653), a large amount of Reaction in anhydrous hydrogen fluoride (JP-A-53-9735), reaction in a large amount of methanesulfonic acid (JP-A-57-154140), reaction in a large amount of trifluoromethanesulfonic acid Method (JP-A-58)
-62132) has been proposed, but these methods are expensive due to the high cost of parafluorobenzoic acid, the use of a large amount of strong acid, and the water produced by the dehydration reaction. The acid is diluted and must be concentrated in order to maintain the required acid concentration, but it has drawbacks such as the large affinity of these acids with water and the difficulty in separating them. There is. Further, a method of performing Friedel-Crafts reaction between parafluorobenzoic acid chloride and phenol (JP-A-53-9735 and JP-A-58-15936) has also been proposed, but parafluorobenzoic acid chloride is also proposed. Is even more expensive.

Further, a method of reacting fluorinated benzene and parahydroxybenzoic acid in anhydrous hydrogen fluoride-boron trifluoride (JP-A-58-15936), a method of reacting in a large amount of trifluoromethanesulfonic acid ( JP-A-58-62132) has also been proposed, but the fact that parahydroxybenzoic acid is a relatively expensive raw material and the separation of water generated by the dehydration reaction from these strong acids is mentioned above. It has drawbacks such as difficulty.

(Means for Solving Problems) Therefore, the present inventors have proposed a method for inexpensively producing 4- (parafluorobenzoyl) phenols from simple compounds such as fluorinated benzene, carbon monoxide, and phenols. As a result of intensive studies, the present invention has been completed.

That is, the present invention relates to a method for producing 4- (parafluorobenzoyl) phenols from fluorinated benzene, carbon monoxide and phenols, which comprises producing 4- (parafluorobenzoyl) phenols from 4- (parafluorobenzoyl) phenols. In producing fluorobenzoyl) phenol, a) an iodination step of reacting iodine and / or hydrogen iodide with fluorinated benzene in the presence of an oxidizing agent to obtain para-iodofluorobenzene, b) the para-iodofluorobenzene An esterification step of reacting iodofluorobenzene with carbon monoxide and a phenol having no substituent in the para position in the presence of a carbonylation catalyst and a base to obtain parafluorobenzoic acid phenyl esters, and c) The parafluorobenzoic acid phenyl esters were treated with 4- (parafluorobenzoyl) phenol in the presence of an acid catalyst. 4- (para-fluorobenzoyl) phenols manufacturing method characterized in that it comprises the rearrangement reaction step of transposition to the class.

The method of the present invention is represented by the following reaction formula.

a) Iodination process b) Esterification process c) Rearrangement reaction step (In the formula, R ¹ , R ² , R ³ and R ⁴ each represent hydrogen or a substituent selected from a lower alkyl group, a lower alkoxy group, a fluorine atom, a nitro group and a cyano group, and these are:
Each may be the same. ) In the iodination step of the present invention, the iodination reaction is carried out by reacting an iodination agent comprising iodine and / or hydrogen iodide and an oxidizing agent with fluorinated benzene. It is preferable to carry out so that the selectivity and the yield of benzene are as high as possible, and it is necessary to carry out so as to obtain an iodinated fluorobenzene mixture containing at least 80 mol% of paraiodofluorobenzene. For that purpose, it is preferable to use 2 mol or more of fluorinated benzene per 1 mol of iodine,
More preferably, it is carried out using 2.5 to 10 mol of fluorinated benzene. If the amount of fluorinated benzene used is less than 2 mol per mol of iodine, the amount of polyiodofluorobenzene such as diiodofluorobenzene increases as a by-product and unreacted iodine remains, resulting in paraiodofluoro. The yield and selectivity of benzene decrease. Further, more than 10-fold mole of fluorinated benzene may be used, but this is not so preferable method because the reactor becomes large and the amount of unreacted fluorinated benzene to be separated increases.

As the oxidizing agent which is combined with iodine and / or hydrogen iodide to serve as an iodination agent, various oxidizing agents can be used. For example, oxidizing inorganic acids such as nitric acid, nitrous acid, and sulfuric acid; oxidizing nitrogen oxides such as NO ₂ and N ₂ O ₃ ; halogen oxyacids such as iodic acid and periodic acid; peracetic acid and peroxide. Peroxides such as hydrogen oxide are preferably used. Particularly preferred are nitric acid and / or nitrogen oxides having oxidizing power, which are inexpensive and have good reactivity.

The amount of the oxidizing agent used is preferably 2 moles or more in the case of a one-electron oxidizing agent and 1 mole or more in the case of a two-electron oxidizing agent per 1 mole of iodine.

The iodination reaction is preferably carried out at a temperature as low as possible in order to maximize the selectivity of paraiodofluorobenzene in the iodinated fluorobenzene mixture,
If the reaction temperature is too low, the reaction rate becomes slow, which is not a preferable method. The selectivity of paraiodofluorobenzene is 80% or more, and in order to react at an appropriate reaction rate, the range of 10 to 150 ° C is preferable, and the range of 30 to 100 ° C is more preferable.

It is not necessary to use a catalyst in the iodination reaction,
It is also possible to use iron-based catalysts such as iron powder, iron chloride, iron bromide and iron iodide, and aluminum-based catalysts such as aluminum chloride and aluminum iodide.

Further, it is also a preferable method to carry out the iodination step without using a solvent other than fluorinated benzene, but a solvent can be used if necessary. As such a solvent, any solvent can be used as long as it does not adversely affect the reaction, for example, lower aliphatic carboxylic acids such as acetic acid and propionic acid; carbon tetrachloride, chloroform, methylene chloride, trichloroethane, etc. Lower aliphatic halogenated hydrocarbons; ethers such as ether and dioxane; carbon disulfide; water and the like.

Depending on the type of iodizing agent used and, in some cases, the type of solvent used, the iodination reaction may be carried out in a heterogeneous liquid phase. , The reaction can proceed smoothly.

The iodination step can be carried out in either a batch system or a flow system,
In the reaction system, it is important to react with the iodination agent in a state in which the fluorinated benzene is present in excess of the equivalent amount, and also to make the reaction rate of iodine and / or hydrogen iodide as high as possible. Reacting is also important.

A separation / purification step is carried out in order to separate and obtain paraiodofluorobenzene from the iodinated fluorobenzene mixture obtained in the iodination step. The reaction mixture that has undergone the iodination step usually contains unreacted fluorinated benzene and para-iodofluorobenzene, orthoiodofluorobenzene, which may be present in excess during the reaction, and in some cases, metaiodofluorobenzene and diiodofluorobenzene. Water containing the iodinated product of polyiodofluorobenzene and the reduced product of the oxidant, or possibly unreacted oxidant left by the use of excess amounts. It is made up of divisions.

When the amount of water or the amount of residual oxidant is smaller than that of the organic part, the organic part can be separated and recovered by a method such as distillation as it is, but usually the organic part is separated into two layers. It is preferable to carry out the step of separating and purifying the organic portion after separating the product by washing with water.

Separation / purification of the iodinated fluorobenzene mixture is carried out by distillation or / and crystallization operation to obtain highly pure paraiodofluorobenzene.

In the esterification step of the present invention, the paraiodofluorobenzene obtained in the iodination step is reacted with carbon monoxide and phenols in the presence of a carbonylation catalyst and a base to give parafluorobenzoic acid phenyl esters. To get

As the carbonylation catalyst, a catalyst containing a white metal element such as palladium, rhodium, ruthenium, platinum or iridium, or a catalyst containing a metal element such as iron, cobalt or nickel is preferably used. Particularly preferred is a palladium catalyst or a nickel catalyst. The palladium catalyst is not particularly limited as long as it contains a palladium element as a component, and palladium may be in a metallic state or may be a component forming a compound. Further, the palladium component is, for example, activated carbon, graphite, silica, alumina, silica-alumina, silica-titania, titania, zirconia, barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, polymer, ion exchange resin, zeolite, It may be supported on a carrier such as molecular sieve, magnesium silicate or magnesia.

Palladium in the metallic state includes palladium metal, palladium black, a compound containing palladium ions supported on the above carrier, and then subjected to reduction treatment with hydrogen, formaldehyde, hydrazine, or an alloy containing palladium or an intermetallic compound. Are used. Examples of alloys or intermetallic compounds include selenium, tellurium,
Sulfur, antimony, bismuth, copper, silver, gold, zinc, tin, vanadium, iron, cobalt, nickel, mercury, lead,
Some include thallium, chromium, molybdenum, and tungsten. Of course, these alloys or intermetallic compounds may be supported on the carrier as described above.

On the other hand, compounds containing palladium include PdCl ₂ and PdB
Inorganic salts such as r ₂ , PdI ₂ , Pd (NO ₃ ) ₂ and PdSO ₄ ; Pd (OCOC
H ₃ ) ₂ , organic acid salts such as palladium oxalate; Pd (CN) ₂ ;
PdO; PdS; M ₂ [PdX ₄ ], M ₂ [PdX ₆ ] palladates (M represents an alkali metal or ammonium ion, X represents a nitro group, a cyano group, a halogen, N
O ₃ , Ammine complexes of palladium such as [Pd (NH ₃ ) ₄ ] X ₄ and [Pd (en) ₂ ] X ₂ (X has the same meaning as above, and en represents ethylenediamine); PdCl ₂ (PhC
N) ₂ , PdCl ₂ (PR ₃ ) ₂ , Pd (CO) (PR ₃ ) ₃ , Pd (PPh ₃ ) ₄ , PdCl (R)
(PPh ₃ ) ₂ , Pd (C ₂ H ₄ ) (PPh ₃ ) ₂ , Pd (C ₃ H ₅ ) ₂ or other complex compounds or organometallic compounds (R represents an organic group such as alkyl or aryl); Complex compounds in which a chelate ligand such as Pd (acac) ₂ is coordinated (acac represents acetylacetone) are used.

The nickel catalyst used in the present invention is not particularly limited as long as it contains a nickel element as a component, and nickel may be in a metallic state or may be a component forming a compound. Further, the nickel component may be supported on the carrier as described above.

On the other hand, compounds containing nickel include NiCl ₂ , NiBr ₂ ,
Halogenated nickels such as NiI ₂ ; NiSO ₄ , Ni (NO ₃ ) ₂ , N
Nickel salts of inorganic acids such as iCO ₃ , Ni (SCN) ₂ and Ni (ClO ₄ ) ₂ ; Nickel salts of organic acids such as Ni (OCOCH ₃ ) ₂ and nickel oxalate; Nickel oxide; Nickel hydroxide; Nickel sulfide Nickel phosphide; Nickel acid salts represented by M ₂ [NiX ₄ ], M ₄ [NiX ₆ ] (M represents an alkali metal or ammonium ion, X is a nitro group, a cyano group, a halogen, NO ₃ , 1 / 2SO ₄ ); [Ni (NH ₃ ) ₄ ] X ₂ , [Ni
Nickel ammine complexes such as (Y) ₃ ] X ₂ , [Ni (Y) ₂ ] X ₂ , [Ni (py) ₄ ] X ₂ (X has the same meaning as above, Y is ethylenediamine, diethylenetriamine, Represents chelating ligands such as biviridine and phenanthroline, py represents pyridine); Complex compounds in which chelating ligands such as Ni (acac) ₂ are coordinated (acac represents acetylacetone); Ni (CO) ₄ , Ni (CO) ₃ (PR) ₃ , Ni (CO) ₂ (P
R ₃ ) ₂ , NiX ₂ (PR ₃ ) ₂ , NiX (PR ₃ ) ₃ , Ni (PR ₃ ) ₄ , NiXPh (P
R ₃ ) ₂ , Ni (RNC) ₂ , [NiX (allyl)] ₂ , Ni (C ₅ H ₅ ) ₂ , Ni (C
O) ₂ (C ₅ H ₅ ) ₂ , NiX (C ₅ H ₅ ) (PR ₃ ), Ni (COD) ₂ , Ni (COD) (PR ₃ )
Complex compounds such as or organic nickel compounds (R and X are as described above, COD represents cyclooctadiene) and the like are used. Note that some of these compounds may be used in the form of hydrates.

These palladium catalysts and nickel catalysts may be used alone or in combination of two or more.

Further, other compounds can be added for the purpose of improving the yield and selectivity, increasing the reaction rate, and decreasing the reaction temperature. Examples of such a compound include a phosphine compound represented by the general formula (I).

PR ₁ ′ R ₂ ′ R ₃ ′ (I) (wherein R ₁ ′ R ₂ ′ R ₃ ′ represents hydrogen, halogen, an aliphatic group, an alicyclic group, an aromatic group, an araliphatic group, These may be the same or may be elements constituting a ring containing phosphorus.) Of course, such a polyphosphine compound containing two or more phosphorus in one molecule may be used. .

Examples of such phosphine compounds include n-octylphosphine, di-n-butylphosphine, diethylbutylphosphine, tri-n-propylphosphine,
Alkylphosphines such as tri-n-butylphosphine, dialkylphosphines and trialkylphosphines; alicyclic phosphines such as cyclohexylphosphine and dicyclohexylphosphine; benzylphosphine, dibenzylphosphine, dibenzylethyl Aroaliphatic phosphines such as phosphine and tribenzylphosphine; methylphenylphosphine, ethylphenylphosphine, dimethylphenylphosphine, methyldiphenylphosphine, methylbenzylphenylphosphine, ethyldiphenylphosphine Mixed phosphines such as inn and dicyclohexyl phenyl phosphine; phenyl phosphine, tolyl phosphine, diphenyl phosphine, triphenyl phosphine, tristril phosphine, diphenyl tolyl phosphine Which arylphosphines, diarylphosphines and triarylphosphines; bis (diphenylphosphino) methane, bis (diphenylphosphine) ethane, orthophenylenebis (diethylphosphine), 2,2'-bis ( Diphenylphosphine) -1,
Diphosphines such as 1'-binaphthyl are used.

Such phosphine compounds may be of one type or of two types.
You may use it in mixture of 2 or more types. Among such phosphine compounds, triarylphosphine is particularly preferably used. Among the triarylphosphines, triphenylphosphine is particularly preferably used because it is easily available.

The base used in the present invention may be either inorganic or organic. Examples of such a base include lithium oxide, lithium peroxide, sodium oxide, sodium peroxide, sodium superoxide, potassium oxide, potassium peroxide, dipotassium trioxide, potassium superoxide, rubidium oxide, rubidium peroxide, Rubidium trioxide, Rubidium superoxide, Rubidium ozonate,
Alkali metal oxides such as cesium oxide, cesium peroxide, cesium trioxide, cesium superoxide, and cesium ozonide; beryllium oxide, magnesium oxide, calcium oxide, calcium peroxide, strontium oxide, strontium peroxide, barium oxide , Oxides of alkaline earth metals such as barium peroxide; lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide,
Alkali metal and alkaline earth metal hydroxides such as cesium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide and barium hydroxide; sodium carbonate, sodium hydrogen carbonate, potassium carbonate, hydrogen carbonate Salts of strong bases and weak acids such as potassium, barium carbonate, sodium silicate, magnesium silicate, potassium aluminate, calcium aluminate, sodium borate and barium borate; carbides such as calcium carbide and cesium carbide; aluminum hydroxide , Hydroxides and oxides of aluminum group metals such as potassium hydroxide, indium hydroxide, thallium hydroxide and thallium oxide; oxides and hydroxides of rare earth elements such as lanthanum oxide, cerium oxide and cerium hydroxide ; Lithium hydride, sodium hydride Hydride such as sodium borohydride, calcium hydride, lithium aluminum hydride, alkali metal or alkaline earth metal sulfide and hydride such as sodium sulfide, sodium hydrogen sulfide, potassium sulfide, calcium sulfide; water; Quaternary ammonium hydroxide compounds such as tetraethylammonium oxide and tetrapropylammonium hydroxide; Quaternary phosphonium hydroxide compounds such as methyltriphenylphosphonium hydroxide and tetramethylphosphonium hydroxide; triethylsulfonium hydroxide and hydroxide Tertiary sulfonium hydroxide compounds such as triphenylsulfonium; salts of strong bases and strong organic acids such as sodium acetate, potassium benzoate, rubidium oxalate, barium propionate; sodium methylate, sodium ethyler , Alkali metal and alkaline earth metal alcoholates such as calcium ethylate; alkali metal and alkaline earth metal phenolates such as sodium phenolate, potassium phenolate, magnesium phenolate, and alkali metal of aromatic hydroxy compounds used Salts or alkaline earth metal salts; amides of alkali metals and alkaline earth metals such as lithium amide, sodium amide, calcium amide, lithium dimethylamide; trimethylamine, triethylamine, tri-n-butylamine, triphenylamine, diethylmethylamine , N, N−
Diethylaniline, N-methylpiperidine, N, N'-diethylpiperazine, N-methylmorpholine, triethylenediamine, hexamethylenetetramine, N, N, N ', N'-tetramethylethylenediamine, dicyclohexylethylamine, 1,2,2 , 6,6-Pentamethylpiperidine, pyridine, quinoline, phenanthroline, indole, N-methylimidazole, 1,8-diazabicyclo- [5,4,0] -undecene-7 (DBU), 1,5-diazabicyclo- [ Tertiary amines such as 4,3,0] -nonene-5 (DBN) and cyclic nitrogen-containing compounds (however, those having no NH group); Crown ether, azacrown ether, thiacrown ether ，
Crown compounds such as azacrown, and complexes of these crown compounds with alkali metal or alkaline earth metal ions are used.

Further, two or more of these basic groups may be present in the molecule, and they may form a part of a polymer such as an anion exchange resin having a quaternary ammonium hydroxide group. May be. Further, these basic substances or groups having basicity may be supported on a solid or chemically bound. These bases may be used alone or in combination of two or more.

The phenols having no substituent at the para position used in the present invention have the general formula Is a compound represented by. (R ¹ , R ² , R ³ and R ⁴ are as described above) Examples of such phenols include phenol,
Cresol, dimethylphenol, trimethylphenol, toteramethylphenol, ethylphenol, diethylphenol, triethylphenol, ethylcresol, methoxyphenol, ethoxyphenol, dimethoxyphenol, methoxycresol, fluorophenol, difluorophenol, fluorocresol,
Nitrophenol, dinitrophenol, nitrocresol, cyanophenol, dicyanophenol, cyanocresol, fluoronitrophenol, fluoronitrocresol, fluorocyanophenol, nitrocyanophenol, cyclohexylphenol, cyclohexylcresol, cyclohexylfluorophenol and the like are used (however, In the case of substituted phenols, those substituted at the para position with respect to the hydroxyl group are excluded).

Among such phenols, phenol or
2,6-Dimethylphenol is particularly preferably used.

The carbon monoxide may be pure carbon monoxide or may be diluted with another gas such as nitrogen, argon, helium, or lower hydrocarbon that does not adversely affect the reaction. Carbon monoxide has a partial pressure of 0.1 to 300 kg / cm ² , preferably 1 to 200 kg /
Used in the cm ² range.

In carrying out the esterification step, the carbonylation catalyst is preferably used as a metal atom contained therein usually in an amount of 0.0001 to 1.000 times by mole with respect to paraiodofluorobenzene.

The base is preferably used in an amount necessary to neutralize the hydrogen bromide formed, but of course, it may be less or more than this.

Further, when an additive such as a phosphine compound is used, it is usually 0.01 to 0.01 to the metal atom in the carbonylation catalyst.
It is preferably used in an amount of 1.000 times the molar amount.

The phenol group is preferably used in at least an equivalent amount with respect to paraiodofluorobenzene. It is also possible to use a solvent by using an excess amount of phenols.

Thus, the esterification reaction can be carried out without using a reaction solvent, but a solvent which does not adversely influence the reaction can be used if necessary. Examples of such a solvent include aliphatic hydrocarbons such as hexane, heptane, octane, decane, and pentadecane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatics such as benzene, toluene, xylene, and mesitylene. Hydrocarbons; nitriles such as acetonitrile and benzonitrile; sulfolane, methylsulfolane,
Sulfones such as dimethylsulfolane; Ethers such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane; Ketones such as acetone and methyl ethyl ketone; Esters such as ethyl acetate and ethyl benzoate; N, N
-Dimethylformamide, N, N-Dimethylacetamide, N
Examples include amides such as methylpyrrolidone and hexamethylphosphoramide.

Esterification reaction is usually 50 ~ 350 ℃, preferably 100 ~ 30
In the range of 0 ℃, the reaction pressure is usually 1 ~ 500kg / cm ² ,
It is preferably carried out in the range of 5 to 300 kg / cm ² .

By carrying out such a carbonylation reaction, the fluorine atom of paraiodofluorobenzene is not replaced,
Parafluorobenzoic acid phenyl esters in which only the iodine atom is substituted with an aryloxycarbonyl group,
It has been found that a high yield of 90% or more and a high selectivity can be obtained.

The salt of hydrogen iodide and a base produced as a by-product in the esterification step is easily separated from the parafluorobenzoic acid phenyl ester by a method such as washing the esterification reaction mixture with water. And from this salt of hydrogen iodide and a base, it can be easily recovered as a hydrogen iodide and a base, or as an iodine and a base, respectively, by a known method. It can be recycled and reused in the esterification step.

In the rearrangement reaction step of the present invention, the parafluorobenzoic acid phenyl ester obtained in the esterification step is subjected to a rearrangement reaction in the presence of an acid catalyst to give the desired 4- (parafluorobenzoyl) phenols. obtain.

As the acid catalyst that can be used in the rearrangement reaction step, it is possible to use an acid catalyst that does not substantially contain water, but in order to maximize yield and selectivity, Lewis acid, and It is preferable to use a strong acidic protonic acid. Such Lewis acids include halides of Group III elements such as boron, aluminum, gallium, indium, thallium, scandium, and yttrium; halides of Group IV elements such as silicon, germanium, tin, titanium, and zirconium. Kind;
Halides of group V elements such as antimony, bismuth, vanadium, niobium, and tantalum, and metal halides such as iron, copper, and zinc are used. The strongly acidic protic acid includes hydrogen fluoride anhydride; fluorocarboxylic acids such as trifluoroacetic acid and perfluoropropionic acid; sulfonic acids such as methanesulfonic acid, ethanesulfonic acid and benzenesulfonic acid; fluorosulfonic acid,
Halogenated sulfonic acids such as chlorosulfonic acid, trifluoromethanesulfonic acid, trichloromethanesulfonic acid, and perfluoroethanesulfonic acid, and halogenated alkanesulfonic acids are used. Further, a high-silica-containing zeolite which is a solid acid, a strongly acidic cation exchange resin, and acids called solid superacid can also be used in the rearrangement reaction of the present invention. A solid superacid is a solid strong acid having an acid strength stronger than 100% sulfuric acid, and examples thereof include SbF ₅ , TaF ₅ , BF ₃ , CF ₃ SO ₃ H, SbF ₅ -HF, S
bF ₅ -FSO ₃ H or a mixture thereof is used as SiO ₂ -Al ₂ O ₃ , SiO _2-
TiO ₂ , SiO ₂ -ZrO ₂ , TiO ₂ -ZrO ₂ , Al ₂ O ₃ -B ₂ O ₃ , SiO ₂ -WO ₃ ,, H
Examples include F-zeolite, Al ₂ O ₃ , SiO ₂ , graphite, cation exchange resin, activated carbon, fluorinated graphite, and the like, and fluorinated sulfonic acid resin. Here, the fluorinated sulfonic acid resin is -CF ₂ SO ₃ H
A resin having a group and / or a CFSO ₃ H group.

These acids can be used alone or in combination of two or more.

Further, this rearrangement reaction may be carried out without a solvent, but a solvent which does not adversely influence the reaction can also be used. Such solvents include carbon disulfide; halogenated hydrocarbons such as chloroform, methylene chloride, carbon tetrachloride, dichloroethane, trichloroethane and tetrachloroethane; halogenated hydrocarbons such as chlorobenzene, dichlorobenzene, bromobenzene and chloronaphthalene. Aromatic hydrocarbons; nitro compounds such as nitrobenzene, nitrotoluene, and nitromethane are used.

This rearrangement reaction is preferably performed under substantially anhydrous conditions. When water is present in the reaction system, hydrolysis of the phenyl ester of p-fluorobenzoic acid occurs, and the desired 4
This is because the yield of-(parafluorobenzoyl) phenol decreases. Therefore, not to mention the water content in the acid catalyst, when using a solvent, it is preferable to keep the water content in the solvent as low as possible.

The temperature and reaction time for carrying out this rearrangement reaction vary depending on other reaction conditions such as the type of catalyst and solvent used, but are usually in the temperature range of -30 to 250 ° C, preferably -20 to 200 ° C.
It ranges from a few minutes to a few tens of hours.

By carrying out such a rearrangement reaction, 4- (parafluorobenzoyl) phenols can be obtained from parafluorobenzoic acid phenyl esters with high yield and high selectivity.

(Effects of the Invention) It has been clarified that the method of the present invention can produce 4- (parafluorobenzoyl) phenols from fluorinated benzene, carbon monoxide and phenols with high yield and high selectivity.

(Examples) Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited to these Examples.

Example 1 288 g of fluorinated benzene and iodine were placed in a flask equipped with a reflux condenser.
Add 254g and heat to 65-70 ° C, then stir with 61% nitric acid.
840 g was gradually added dropwise. After completion of dropping, stirring was continued for further 3 hours to complete the reaction. Iodine was completely consumed. The reaction mixture was separated into two layers, the organic layer was washed with water, an aqueous solution of sodium carbonate and water in this order, and then distilled.
After distilling off the excess fluorinated benzene and a small amount of water, the composition was para-iodofluorobenzene.
91.9%, orthoiodofluorobenzene 7.6%, metaiodofluorobenzene 0.5%, the weight is 442g.
(99.5% yield as monoiodofluorobenzene).

The following esterification step was carried out using paraiodofluorobenzene obtained by rectifying this monoiodofluorobenzene using a packed column rectification apparatus equipped with a reflux device.

Paraiodofluorobenzene 22.2 g, phenol 11.3 g, tri-n-butylamine 22.2 g, and palladium chloride 40 mg were put into the autoclave, and after the inside of the autoclave was replaced with carbon monoxide, carbon monoxide was pressed into 30 kg / cm ² . . After reacting at 200 ° C for 2 hours with stirring, the mixture was cooled and the reaction mixture was analyzed. As a result, the reaction rate of paraiodofluorobenzene was 10
At 0%, yield of parafluorobenzoic acid phenyl ester was 9
It was obtained with a selectivity of 9% and a selectivity of 99%.

Using parafluorobenzoic acid phenyl ester obtained by vacuum distillation of the esterification reaction mixture,
The next rearrangement reaction step was performed.

Add 10.8 g of phenyl parafluorobenzoate and 22 g of trifluoromethanesulfonic acid to the flask and stir at 45-50 ° C with stirring.
And reacted for 2 hours. After that, most of trifluoromethanesulfonic acid was distilled off under reduced pressure, and then the reaction mixture was put into cold water. The white crystals thus formed were separated by filtration, dried under reduced pressure and analyzed. As a result, it was found that 4- (parafluorobenzoyl) phenol was obtained in a yield of 96% and a selectivity of 96%.

Since the unreacted fluorinated benzene can be recovered and reused in the iodination step by circulation, in this example, 4- (parafluorobenzoyl) phenol was obtained in a yield of 87% and a selectivity of 87 with respect to the reacted fluorinated benzene. It shows that it was obtained in%.

Example 2 A flask equipped with a reflux condenser was charged with 884 g of fluorinated benzene, 687 g of finely ground iodine and 145 g of 61% nitric acid, and the mixture was heated to 50-54.
Heat to ℃. Then, 1 kg of 61% nitric acid was gradually added dropwise with stirring. After completion of dropping, stirring was continued for further 5 hours to complete the reaction. Iodine was completely consumed. Example 1
After performing the same post-treatment,
Monoiodofluorobenzene consisting of 92.2%, orthoiodofluorobenzene 7.4%, and metaiodofluorobenzene 0.4% was obtained with a yield of 99.6%.

By cooling this iodofluorobenzene mixture to −30 to −40 ° C., para-iodofluorobenzene crystallized was obtained. The following esterification step was performed using this paraiodofluorobenzene.

Paraiodofluorobenzene 22.2 g, 2,6-dimethylphenol 14.6 g, tri-n-butylamine 22.2 g, and nickel (II) acetylacetonate 0.77 g were placed in an autoclave, and the inside of the autoclave was replaced with carbon monoxide. Carbon monoxide was pressed into 50 kg / cm ² . 200-2 under stirring
After reacting at 20 ℃ for 2 hours, cooled and analyzed the reaction mixture, the reaction rate of parafluoroiodobenzene is 100%
Thus, parafluorobenzoic acid-2,6-dimethylphenyl ester was obtained with a yield of 98% and a selectivity of 98%.

19.5 g of this parafluorobenzoic acid-2,6-dimethylphenyl ester and 76 g of methanesulfonic acid were placed in a flask and reacted under stirring at 150 ° C for 1.5 hours, and then most of the methanesulfonic acid was distilled off under reduced pressure. I left. Then, the reaction mixture was put into cold water to separate white crystals that had formed, and the crystals were dried under reduced pressure. The white crystals were 4- (parafluorobenzoyl) -2,6-dimethylphenol, and the yield was 97.
The selectivity was 99% in%.

Since unreacted fluorinated benzene can be recovered and recycled in the iodination step, in this example, 4- (parafluorobenzoyl) -2,
It shows that 6-dimethylphenol was obtained with a yield of 87% and a selectivity of 89%.

Example 3 Fluorine-containing benzene (192 g), iodine (63.5 g), periodic acid dihydrate (28.4 g), acetic acid (500 ml) and sulfuric acid (1 g) were placed in a flask, and the temperature was 45 to 50 ° C.
And reacted for 5 hours under stirring. After the completion of the reaction, fluorinated benzene and acetic acid were distilled off, and the mixture was washed with an aqueous sodium carbonate solution and water and then dried.

The reaction product consisted of paraiodofluorobenzene 93.0%, orthoiodofluorobenzene 6.7%, and metaiodofluorobenzene 0.3%, and the yield as monoiodofluorobenzene was 98.8%.

This monoiodofluorobenzene mixture was crystallized by the same method as in Example 2 to obtain 22.2 g of para-iodofluorobenzene, 11.3 g of phenol and tri-n-.
Butylamine (22.2 g), NiCl _{2 (} 0.1 g) and triphenylphosphine (0.2 g) were placed in an autoclave and reacted in the same manner as in the esterification step of Example 2, with the result that the reaction rate of paraiodofluorobenzene was 100%. Then, p-fluorobenzoic acid phenyl ester was obtained with a yield of 97% and a selectivity of 97%.

Using parafluorobenzoic acid phenyl ester obtained by vacuum distillation of the esterification reaction mixture,
The next rearrangement reaction step was performed.

15 g of parafluorobenzoic acid phenyl ester and 150 g of liquid anhydrous hydrogen fluoride were placed in a polyethylene flask equipped with a reflux condenser and reacted at 0-10 ° C. for 6 hours with stirring. After the reaction
The system was raised to 20-40 ° C and anhydrous hydrogen fluoride was recovered by distillation. The obtained residue was washed with a small amount of diluted alkaline water and distilled water, and then dried under reduced pressure. As a result of analyzing the product, the reaction rate of parafluorobenzoic acid phenyl ester was 67%, and 4- (parafluorobenzoyl) phenol was produced in a yield of 66.3% and a selectivity of 99%. The isomer 2- (parafluorobenzoyl) phenol was only detected at 1%.

Unreacted para-iodofluorobenzene and para-fluorobenzoic acid phenyl ester can be recovered and reused in circulation in the iodination step and rearrangement reaction step. −
(This indicates that parafluorobenzoylphenol was obtained with a yield of 88.2% and a selectivity of 88.2%.

Example 4 The following esterification step was performed using the paraiodofluorobenzene obtained in Example 2.

Paraiodofluorobenzene 22.2 g, 2,6-dimethylphenol 14.6 g, palladium acetate 50 mg, pyridine 15 g, tris- (4-methylphenyl) phosphine 0.5 g was placed in an autoclave, and after replacing the inside of the autoclave with carbon monoxide, Heated to 180 ° C. At this temperature the reaction pressure is 20 kg /
While continuously introducing carbon monoxide so as to keep cm ² ,
As a result of reacting for 2 hours with stirring, parafluorobenzoic acid-2,6-dimethylphenyl ester was obtained in a yield of 99% and a selectivity of 9%.
Obtained in 9%.

Next, 12.2 g of this parafluorobenzoic acid-2,6-dimethylphenyl ester, 7.3 g of anhydrous aluminum chloride, and 70 ml of dry orthodichlorobenzene were placed in a flask,
The reaction was carried out for 4 hours with stirring at ℃. After the reaction, orthodichlorobenzene was distilled off under reduced pressure, and a hydrochloric acid aqueous solution was added to the residue and stirred. Then, extraction was performed with ethyl acetate, and ethyl acetate was distilled off from the extract to obtain 4- (parafluorobenzoyl) -2,6-dimethylphenol in a yield of 94%. The yield based on the reacted fluorinated benzene was 85.5%.

Example 5 The following esterification step was carried out using the paraiodofluorobenzene obtained in Example 2.

Paraiodofluorobenzene 22.2g, phenol 11.3g,
Triethylamine 12.2 g, 5% Pd / C 1 g with palladium 5w% on activated carbon, and 0.5 g triphenylphosphine were placed in an autoclave. After replacing the inside of the autoclave with carbon monoxide, carbon monoxide up to 50 kg / cm ^2. Pressed in. After reacting at 170 ° C for 2 hours with stirring, benzene was added to the reaction mixture, Pd / C and triethylamine hydrogen iodide salt were separated by filtration, and the liquid components were analyzed. As a result, parafluorobenzoic acid phenyl ester was found. It was produced with a yield of 99.8% and a selectivity of 99.8%.

After distilling off benzene from the filtrate containing the esterification reaction mixture, vacuum distillation was performed to obtain highly pure parafluorobenzoic acid phenyl ester.

This parafluorobenzoic acid phenyl ester 17.3g, methanesulfonic acid 50g, trifluoromethanesulfonic acid 1g
Was placed in a flask and reacted at 100 ° C. for 30 minutes under stirring, and most of methanesulfonic acid and trifluoromethanesulfonic acid were distilled off under reduced pressure. Then, the reaction mixture was put into cold water to separate white crystals that had formed, and the crystals were dried under reduced pressure. 4- (parafluorobenzoyl) phenol was obtained with a yield of 96% and a selectivity of 96%. The yield based on the reacted fluorinated benzene was 88%.

The ortho and meta-iodofluorobenzene produced as by-products in the iodination step of these examples are subjected to a hydrogenolysis reaction in the presence of a catalyst and a base,
Since it can be quantitatively converted into a fluorinated benzene and a salt of hydrogen iodide and the base, if the fluorinated benzene recovered by performing this operation is recycled, the fluorinated benzene standard in these examples can be used. It goes without saying that the yields of 4- (parafluorobenzoyl) phenols rise to even higher values around 95%, respectively.

Preferred embodiments of the present invention are as follows.

(1) The method according to claim 1, wherein the oxidizing agent is nitric acid and / or nitrogen oxide having oxidizing power. (2) The method according to claim 1, wherein the phenols are phenol or 2,6-dimethylphenol. The method according to claim 3, wherein the carbonylation catalyst is a palladium catalyst or a nickel catalyst, and the acid catalyst is a Lewis acid and / or a strongly acidic protic acid.

Claims (1)

[Claims] 1. A process for producing 4- (parafluorobenzoyl) phenols using fluorinated benzene, carbon monoxide and phenols, which comprises a) iodine and / or iodide in the presence of an oxidizing agent. An iodination step of reacting hydrogen with fluorinated benzene to obtain para-iodofluorobenzene, and b) having carbon monoxide and a substituent at the para position in the presence of a carbonylation catalyst and a base. Esterification step to obtain parafluorobenzoic acid phenyl esters by reacting with non-phenols, and c) the parafluorobenzoic acid phenyl esters in the presence of an acid catalyst, 4- (parafluorobenzoyl) phenols Of 4- (parafluorobenzoyl) phenols characterized by including a rearrangement reaction step of rearrangement