JPS61221146A - Production of difluorobenzophenone - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a monomer for heat-resistant polymers, an intermediate for agricultural chemicals, drugs, etc., simply and economically, by reacting fluorobenzene with carbon monoxide and molecular oxygen catalytically in the presence of a catalyst comprising specific components. CONSTITUTION:Fluorobenzene is reacted with carbon monoxide and molecular oxygen in the presence of a catalytic system containing palladium, iron and a chlorine ion as components usually at 30-350 deg.C, preferably 80-300 deg.C at 1-500kg/cm<2>, preferably 5-300kg/cm<2>, to give the aimed compound. Preferably the amount of palladium [e.g., PdCl2, Pd(Cd3H5)2, etc.] used as the catalytic component is 0.0001-100mol based on 1mol flurobenzene, the amount of iron (FeCl2, FeOCl, etc.) is 0.1-1,000atom based on 1atom palladium and the amount of the chlorine ion (hydrogen chloride, etc.) is 1-100atom based on 1 iron atom.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing difluorobenzophenone, which is important as an intermediate for heat-resistant polymers, agrochemicals, pharmaceuticals, etc.

[Conventional technology]

Difluorobenzophenone, especially its 4,4' monomer, 4,4'-difluorobenzophenone, has recently attracted particular attention as a monomer for aromatic polyetherketone polymers with good heat resistance and chemical resistance. There is a demand for the development of inexpensive manufacturing methods. The following methods have been proposed for producing 4,4'-difluorobenzophenone.

(114,4'-diaminodiphenylmethane is diazotized in anhydrous hydrogen fluoride or a concentrated aqueous hydrogen fluoride solution, and then the decomposition and fluorination of the diazonium salt and the oxidation of the methylene group to the ketone group are simultaneously carried out in the presence of nitrous acid. Method (Japanese Unexamined Patent Publication No. 54-132558).

(2) 1.1-bis(4-fluorophenyl)-2
゜2.2-) A method of treating dichloroethanol with an alkali (Japanese Unexamined Patent Publication No. 154139/1983).

+31 A method of reacting 4.4'-cyclopenzophenone with an alkali fluoride (Japanese Patent Application Laid-open No. 169441/1983).

(A method of reacting 414-fluorobenzoyl chloride and fluorinated benzene in anhydrous hydrogen fluoride in the presence of boron trifluoride (Japanese Patent Application Laid-Open No. 58-12
Publication No. 4731).

(5) 1.1-bis(4-fluorophenyl) -
A method of oxidizing 2,2°-dichloroethylene with nitric acid (Japanese Unexamined Patent Publication No. 126829/1982).

However, these methods require the use of large amounts of anhydrous hydrogen fluoride, which is dangerous and difficult to handle (methods (11 and (4)), and the production of diazonium fluoride, which is unstable and has the risk of explosion. (Method (1)) and that complicated steps are required to produce the raw material compound (Method (2)).

(31, (sl)), the reaction must be carried out at high temperature for a long time, therefore side reactions increase and the yield is not very high, as well as it is difficult to separate the product from the raw materials and by-products ( Due to method (3)), etc., there were problems with K carried out industrially.

On the other hand, it is known that difluorobenzophenone can be synthesized by reacting a fluorine-containing organometallic compound with carbon monoxide or a metal carbonyl compound in the presence of a catalyst. For example, 4,4'-difluoropenzophenone is obtained by reacting parafluorophenyl mercuric promide with cobalt octacarbonyl (D).

5eyfer th et al., J. Am. Chem. Soc.
, vol. 90, p. 540, 1968), 4,4'-difluoro Benzophenone was obtained (Sansui et al., Journal of the Chemical Society of Japan.

310 pages, 1982). However, all of these reactions require the preparation of fluorine-containing organometallic compounds, which are expensive raw materials.
There were problems with the industrial implementation of K.

[Means and effects of the invention]

Therefore, the present inventors conducted intensive research to see if it would be possible to directly introduce a carbonyl group into fluorinated benzene for condensation, and as a result, they were able to carry out an oxidative carbonylation reaction in the presence of several types of catalysts. Therefore, we have discovered a completely new reaction that enables the catalytic production of difluorobenzophenone, and have completed the present invention.

That is, the present invention resides in a method for producing difluorobenzophenone, which is characterized by reacting fluorinated benzene with carbon monoxide in the presence of a catalyst system containing palladium, iron, and chloride ions as components, and molecular oxygen.

The production of difluoropentuphenone by oxidative carbonylation of fluorinated benzene, which is a novel reaction of the present invention, is represented by the following reaction formula.

In this reaction, 4,4'-difluorobenzophenone is obtained as the main product, but in some cases a mixture containing small amounts of 2,4'-difluorobenzophenone and 2,z-difluorobenzophenone is obtained.

Palladium used as a catalyst component in the present invention is not particularly limited as long as it contains the element palladium as a component, and palladium may be in a metallic state or may be a component forming a compound. Examples of the palladium component include activated carbon, graphite, silica, aluminum, silica-alumina, silica-titania, titania, and zirconia.

It may be supported on a carrier such as barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, polymer, ion exchange resin, zeolite, molecular sheep, magnesium silicate, magnesia, or the like.

Metallic palladium includes palladium metal, palladium black, palladium ion-containing compounds supported on the above-mentioned carrier and then reduced with hydrogen, formaldehyde, hydrazine, etc., and palladium-containing alloys or metals. Intermediate compounds etc. are used. Examples of alloys or intermetallic compounds include selenium, tellurium, sulfur, antimony, bismuth, copper, silver, gold, zinc, and tin.

Vanadium, iron, cobalt, nickel, mercury, a.

Examples include those containing 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, examples of compounds containing palladium include PdCl.

PdBr, , PdI2. Pd(NO8), ,
Pd50.7'J: Which inorganic salt: Pd (OCOCH
8), Organic acid salts such as palladium oxalate; P
d(CN'h: PdO; PdS: Pigeon (PdX
4) Palladate salts represented by 2Mt(PdXa) (M is an alkali metal, ammonium ion, nido a group,
(represents a cyano group, X represents a halogen); (P
d(NH8),]X! .

CPd(en>t3Xa) Amine complexes of palladium (X has the same meaning as above, en represents ethylene cyabane); PdC1, (PhCN)1,
PdC1, (PRa)t.

Pd(Co)(PR,)8. Pd(PPh,),
PdC1(R)(PPh,)t.

Pd(C2H4)(PPhs)t, Pd(Cs
Complex compounds such as Hs)x or organometallic compounds (R represents an organic group); complex compounds coordinated with a chelate ligand such as Pd(acac)t, etc. are used.

The iron used as the catalyst component used in the present invention may be any compound containing iron as a component, but compounds containing iron in an oxidized state are more preferable. Such iron compounds include, for example, FeCl
, -FeCl5, Fe(C10Jt -Fe(CI
O, ), t FeBr, , FeBr, *Fe
1. t FeI, + Fe(IOs)s.

FeSO41Fe, (So, ), l Fe(NOx)
s # Fe (SCN) t I Fe (SCN).

salts such as, and hydrates of these salts, N2F
ferrates such as e04+13aFeO; FeK(S
o, 32., l 2H, O, Fe(NH4) (804
)*” 12H20, FeRb(SO4)t'12H2
0, FeC3 (SOJ2.

Iron products such as 12H,0, FeT1 (804), and 12H20; Fe(CH,Co,), , Fe
(CHsCot)s, Fe, (OH)t(cHs■
,),.

Fe, (OH), (CI(scO2)6c1, Fe
5(CaHeeOt)y(OH)y, iron oxalate (■1
．． Organic acid irons such as tiul oxalate and iron citrate (tut), and hydrates of these salts: FeOt Fe,
Os tFe, 0. Iron oxides such as Fed(OH)
Various iron oxide hydroxides represented by: Fe(OH),
, Fe(OH), and other iron hydroxides; FeS,
Iron sulfides such as Fe5S4, Fe, S, etc.; F
e0C1, Fe0Br, etc. (1) Oxybaro )j 7
Chemical P class; Fe, MgO, , Fe, MnC, , Fe, Co
d, Fe, N1o4. Fe1Zn04+Fe, YI
Ferrites such as OH; [(C'tHs)iN)t(
FeC14).

' ((CtHs)tN)(FeC14), ((CtHs)tN)(FeC14), ((CtHs)tN
s) iNMFeBr,), Nat[Fe(OH)a).

Ba5(Fe(OH)say, [Fe(CONtH*
)s) CI, -aH,0Nas(Fe(CeOJs)'
,9HtO,(Fe(Nl(s)a)C1t-(Fe
(C5HsN% ICJ *, Km [Fe (
Iron complex compounds such as CN)a] are used. Of course, substances containing both palladium and iron can also be used.

Among these iron compounds, FeClt, FeC15,
Particularly preferred are chlorine-containing compounds such as Fe0C1.

Chlorine ions used as catalyst components include tertiary amine hydrochlorides such as hydrogen chloride nitriethylamine hydrochloride and tri-n-butylamine hydrochloride; chlorine-containing phosphorus compounds such as phosphorus chloride, phosphorus oxychloride, and diphenylphosphine chloride. ; It may be added to the reaction system as a compound such as chlorine-containing sulfur compounds such as thionyl chloride and sul7lyl chloride, or it may not be added if the palladium compound and/or iron compound contains chlorine ions. . The chlorine ion is usually 0.1 to 10
It is used in an amount of 1 to 100 times, preferably 1 to 100 times.

In carrying out the reaction of the present invention, the amount of palladium used is not particularly limited, but it is usually 0.00001 to 1000 times, preferably 0.0001 to 100 times the amount of palladium atoms per mole of fluorinated benzene. Used in range.

In addition, iron is usually α0 per palladium atom as an iron atom.
It is used in an amount of 10,000 times to 1, preferably 1,000 times to Oll.

The carbon monoxide used in the present invention may be pure or may be diluted with other gases that do not adversely affect the reaction, such as nitrogen, argon, helium, lower hydrocarbons, or carbon dioxide. .

-If carbonization! ! Normal partial pressure 0.1 to 500 kl
l/cyt”, preferably 1 to 300 kli/ati
' used in the range.

Furthermore, the molecular oxygen used in the present invention refers to pure oxygen or a substance containing oxygen, which may be air, or other gases that do not inhibit the reaction with air or pure oxygen, such as nitrogen, argon, helium, carbon dioxide gas, etc. It may be diluted by adding an inert gas such as. In some cases, it may also contain gases such as hydrogen, carbon oxide, hydrocarbons, and halogenated hydrocarbons.

Molecular oxygen, usually at a partial pressure of O-05 to 200 9/e
rr? , preferably in the range of 0.5 to 100 kg/ctl, but preferably under conditions such that the gaseous mixture of carbon oxide and fluorinated benzene is outside the explosive limits.

In the method of the present invention, no reaction solvent may be used, but if necessary, a solvent that does not adversely affect the reaction may be used. Examples of such solvents include hexane, hegetane, and octane.

Aliphatic hydrocarbons such as decane and pentadecane; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Nitriles such as acetonitrile and benzonitrile; Sulfones such as sulfolane, methylsulfolane and dimethylsulfolane: Tetrahydrofuran, 1 , 4-dioxane, 1,2-dimethoxyethane and other ethers:
Ketones such as acetone and methyl ethyl ketone; ethyl acetate.

Esters such as N,N-dimethylformamide.

Amides such as N,N-dimethylacedoamide, N-methylpyrrolidone, hexamethylphosphoramide; methylene chloride, C2oform, carbon tetrachloride.

Examples include chlorinated aliphatic hydrocarbons such as dichloroethane, trichlorethane, and tetrachloroethane.

The reaction of the present invention is usually carried out at 30 to 350°C, preferably at 80°C.
~300°C, and the reaction pressure is usually IS-5.
00 to 9/(but preferably 5 to 300kli/art
” will be implemented within the scope of ``.

The reaction time varies depending on the catalyst system used, the type and amount of raw materials, and other reaction conditions such as temperature and pressure, but is usually from several minutes to several tens of hours.

As for the reaction method, any method such as a batch method, a continuous method, or a combination thereof can be adopted.

〔Effect of the invention〕

It has been revealed for the first time that difluorobenzophenone can be catalytically produced from fluorinated benzene and carbon dimolecular oxygen by the method of the present invention.

〔Example〕

EXAMPLES Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 Fluorinated benzene 3oII, palladium chloride α88trm
o 1. Ferric chloride 36 rrmol hastelloy-C
After replacing the air in the system with carbon monoxide, 70 kl/cta" of carbon oxide and then 20 kl//cm" of air were introduced to bring the total pressure to 90 kl//cm.
kg/d. After reacting at 170°C for 3 hours with stirring, the reaction solution cooled to room temperature was analyzed, and the result was 4.4.
'-difluorobenzophenone 5.3 rrmol
It was found that it was generated. This is 6 times the molar amount per palladium chloride used, indicating that the Ba2 chloride acts as a catalyst.

Incidentally, almost no side reaction products were detected, and the selectivity to difluorobenzophenone was 98%.

Example 2 The reaction was carried out in the same manner as in Example 1 except that iron oxychloride sOrrmol was used instead of ferric chloride. As a result, 4,4'-difluorobenzophenone was converted to s, 7
rrmol was produced.

Example 3 A reaction was carried out in the same manner as in Example 1 except that 1rrmol of K and palladium black was used instead of palladium chloride. As a result, 18 m of 4,4'-difluorobenzophenone was obtained.
mol was generated.

Example 4 α-FelOB 20 rrmol instead of ferric chloride
, The reaction was carried out in the same manner as in Example 1 except that 30 mmol of triethylamine hydrochloride was used. As a result,
4.4'-Schiff # o benzophenone is Z 2 r
mxol was being produced.

Claims (1)

[Claims] (1) A method for producing difluorobenzophenone, which is characterized by reacting fluorinated benzene with carbon monoxide in the presence of a catalyst system containing palladium, iron, and chloride ions as components, and molecular oxygen.