JPS61238763A - Production of nitrophenol - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as a raw material of agricultural chemicals, pharmaceuticals, dyes and monomers of heat-resistant polymer, quantitatively in high yield, by cleaving allyl nitrophenyl ether with formic acid in the presence of palladium and trivalent phosphine compound. CONSTITUTION:The objective compound can be produced by reacting allyl nitrophenyl ether (e.g. alkyl m-nitrophenyl ether) with formic acid or its salt in an inert solvent in the presence of a palladium catalyst and a trivalent phosphine compound at 20-200 deg.C. The amount of the palladium catalyst is 0.01-2mol% based on the raw material, that of the trivalent phosphine compound is 3-20mol per 1mol of the palladium catalyst and that of formic acid and formic acid salt is 1-5mol per 1mol of the raw material. EFFECT:Hardly producible m-nitrophenol can be produced in high yield at a low cost without using complicate process.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for producing nitrophenol.

More specifically, the present invention relates to a method for producing allyl nitrophenyl ether, a catalytic amount of a palladium compound, and a catalytic amount of trivalent monomer.

Nitrophenol is a very important compound as a raw material for agricultural chemicals, medicines, dyes, and monomers for heat-resistant polymers.

(Prior Art) It is widely known that 0- and p-nitrophenol can be easily produced industrially by nitration of phenol. On the other hand, regarding the production method of m-nitrophenol, (1) a method of hydrolyzing m-nitroaniline via a diazonium salt (Org, 5ynth, C
o11. Vol 1, 404 (1941)), (2
) A method of hydrolyzing furkyl m-nitrophenyl ether (Japanese Patent Application Laid-Open No. 157-059-1982)
, (3) Method of hydroxylating nitrobenzene using hydrogen peroxide (Ger, Of fen, DFi3.1
35.559! etc.) are only known.

However, regarding these conventional techniques, method (1) requires the use of a large amount of acid and water, resulting in very low volumetric efficiency, and also requires the treatment of a large amount of waste acid. ) method requires the use of large amounts of hydrochloric acid or hydrobromic acid, which causes corrosion of the reaction equipment due to the acid, and the acid used is diluted after the reaction, making it difficult to reuse repeatedly. Even when using hydrochloric acid, which is moreover cheap, the reaction must be carried out at high temperature and under pressure. Furthermore, method (3) produces a mixture of positional isomers, has extremely low yields, and has various drawbacks such as safety issues, and these drawbacks need to be resolved for industrial implementation. There is.

m-Nitrophenol is used as a raw material for various fine chemicals and [-
Although it is a very important substance in
Furthermore, there is no known method for manufacturing it at low cost.

(Problems to be Solved by the Invention) The object of the present invention is to provide an industrial method for producing m-nitrophenol that does not have the disadvantages of the prior art described above.

(Means for Solving the Problems) The present inventors have made various considerations and investigations in order to achieve the above object.

Therefore, as a method to overcome the drawbacks of the conventional technology, we came up with the idea of using allyl nitrophenyl ether as a raw material.
-We conducted extensive research on the production method of nitrophenol.

Already, PdCl2 or pd(aH3Co)2 and triglycerides have been used. For example, when allyl phenyl ether is reacted in the presence of a catalytic amount of Pd C12 or pd(CH31:!O),2 catalyst and triphenylphosphine, phenol and propylene are produced.
gew, chem.

It is also known that when this reaction is applied to various allyl phenyl ethers, 1-olefins and phenols are produced when formic acid or ami/salts of formic acid are used. (Tet-rahe
Dron Lett, 1979.615). On the other hand, when formic acid or triethylamine salt of formic acid acts on an aromatic nitro compound in the presence of pd/c or Pd(OH3C○)2 and a trivalent phosphine compound, some of the nitro groups may be reduced to amines. Conventionally known, in particular, the method using triethylamine salt of formic acid is one of the effective methods for reducing aromatic nitro compounds to aromatic amines (J, Org, Ohem, 42).

3491 (1977)).

Among these conventional techniques, there have been no attempts to produce nitrophenol by performing only a cleavage reaction without reducing the nitro group using an allyl nitroph that has an easily reducible group such as a nitro group in the molecule. It had not been done.

Such an attempt of the present invention surprisingly revealed that the nitro group was reduced by treating allyl nitrophenyl ether with formic acid or a salt thereof in the presence of a catalytic amount of a Pd catalyst and a catalytic amount of a trivalent phosphine compound. The present inventors have discovered that the corresponding nitrophenol can be produced quantitatively by selectively removing only the allyl group without being removed, and have completed the present invention.

That is, the present invention provides a novel method for producing nitrophenol, which is characterized in that allyl nitrophenyl ether is cleaved using formic acid or a salt thereof in the presence of a catalytic amount of a Pd catalyst and a catalytic amount of a trivalent phosphine compound. It is about the method.

The compounds produced by the method of the present invention are three types of isomers of nitrophenol, specifically 0-nitrophenol, m-nitrophenol, and p-nitrophenol. In particular, the method of the present invention is useful for producing m-nitrophenol, which has conventionally been difficult to produce industrially.

The compounds used as raw materials in the method of the present invention are three types of isomers of allyl nitrophenyl ether, specifically allyl 0-nitrophenyl ether, allyl m-
Nitrophenyl ether is allyl p-nitrophenyl ether. These compounds can be easily produced by the condensation reaction of various isomers of the corresponding dinitrobenzene, chloronitrobenzene, or bromonitrobenzene with allyl alcohol (for example, JP-A-58
-180.461, 59-25.353, 59-4
4.343).

As the Pd catalyst, a zero-valent or divalent palladium compound is used.

Specifically, the zero-valent Pd catalyst includes tetrakis(triphenylphosphine)palladium, bis(triphenylphosphine)palladium, tetramethylpalladium,
(maleic anhydride)bis(triphenylphosphine)
Palladium, among other things.

Specifically, the divalent Pd catalyst includes palladium chloride,
Examples include palladium acetate, bis(pentanedionato)palladium, bis(triphenylphosphine)palladium chloride, bis(benzonitrile)palladium chloride, and the like. The amount of such a catalyst used is not particularly limited, but usually 0.01 to 2 moles of the number of moles of the raw material is sufficient.

Examples of hexavalent phosphine compounds include trialkylphosphines such as triethylphosphine, triisopropylphosphine, and trilobylphosphine, tricycloalkylphosphines such as tricyclohexylphosphine, triphenylphosphine, tritolylphosphine, etc.
! Triarylphosphines such as J(+)-1'lolophenyl)phosphine, trialkylphosphines such as tribenzylphosphine, and phosphines crosslinked with methylene chains such as 1,2-bis(diphenylphosphine)ethane are used.

The amount of these used is not particularly limited, but usually 3 to 20 times the molar amount of the Pd catalyst used is sufficient.

The purity of the formic acid used is not particularly limited, and quartz-containing crystals are also acceptable. Furthermore, there is no problem in using a formic acid salt instead of formic acid.

Examples of formic acid salts include alkali metal salts such as lithium formate, sodium formate, and potassium formate; alkaline earth metal salts such as magnesium formate and calcium formate;
Primary alkylamine salts such as ammonium formate, methylamine salts of formic acid and ethylamine salts, secondary alkylamine salts such as dimethylamine salts and diethylamine salts of formic acid,
In addition to 6-class alkylamine salts such as triethylamine salt of formic acid, aromatic amine salts such as aniline salt and pyridine salt of formic acid are used.

The amount of formic acid and formic acid salt used is not particularly limited.

Usually, 1 to 5 times the mole, preferably 1 to 2 times the mole of the raw material is sufficient.

The reaction solvent is not particularly limited as long as it is inert to the reaction, and includes, for example, alcohols such as methanol, ethanol, and inpropyl alcohol, alcohols such as ethylene glycol and fluoropylene glycol, and ether. , ethers such as dioxane, tetrahydrofuran and methyl cellosolve, aliphatic hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate, dichloromethane, chloroform, Halogenated hydrocarbons such as carbon tetrachloride, 1,2-dichloroethane, 1,1,2-trichloroethane, and tetrachloroethane, N,N-dimethylformamide, dimethylsulfoxide, and the like can be used. Note that when using a reaction solvent that is immiscible with water, if the reaction progresses slowly, it can be accelerated by adding a commonly used phase transfer catalyst such as a quaternary ammonium salt or a quaternary phosphonium salt.

The amount of the solvent to be used is not particularly limited as it is sufficient to suspend or completely dissolve the raw materials, but usually 0.5 to 10 times the weight of the raw materials is sufficient.

The reaction temperature is not particularly limited. Generally 20~200℃
be carried out within the range of The reaction time is also not particularly limited, and is usually 30
It ranges from minutes to 10 hours. There are no particular restrictions on the reaction pressure; normal pressure is usually sufficient.

Although the embodiment of the reaction is not particularly limited, usually, raw materials are added to a state in which a Pd catalyst and a trivalent phosphine compound are dissolved in a solvent, and then formic acid is added dropwise or formic acid is added at a predetermined temperature while stirring. The reaction is carried out by adding salt little by little.

The end point of the reaction can be determined by thin layer or liquid chromatography or by cessation of the evolved gas.

After the reaction is completed, the reaction solution is filtered to remove the catalyst, the solvent is distilled off, and then distilled under reduced pressure to obtain the desired nitrophenol in high purity and almost quantitatively.

(Functions and Effects) According to the method of the present invention, nitrophenol can be produced in high purity and almost quantitatively under mild conditions by the cleavage reaction of allyl nitrophenyl ether. In particular, the method of the present invention provides an extremely excellent method for producing m-nitrophenol, which has hitherto been difficult to produce industrially, at low cost and in a high yield without resorting to complicated steps.

(Example) Hereinafter, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 Palladium acetate 357119 (0,16 mmot)
and triphenylphosphine 380 rrui (1,4
! 5 mmo7) was dissolved in 70 mm of methyl cellosolve, and further 20 mm of allyl m-nitrophenyl ether was dissolved in 70 mm of methyl cellosolve. (
0,112 mot). Heated to 85℃ and added 86 thiformic acid 7.21 (0,13
mol)? ' was added dropwise at 85-95°C for about 1 hour. 100-110
Stir for a further 45 hours at <0>C. According to liquid chromatography, the yield of m-nitrophenol was 100%. After filtration and washing with methyl cellosolve, the resulting oil was distilled under reduced pressure to obtain m-nitrophenol as a pale yellow oil, which immediately crystallized. Yield 1452 (93% yield), bp, 120-12
2°/3rd edition, mp, 95-96°C, yellow crystals.

Example 2 20 mm of palladium chloride (o, 11 mmoz) and 293 mm of triphenylphosphine (1,12 mmot) were dissolved in 50 m of methyl cellosolve, and allyl m-nitrophenyl ether 10 F (0,056 mot) and 86 mm of thiformic acid were dissolved. Add 92 (0°0671 mot). 90~
Stir at 100'C for about 1 hour. The same post-treatment as in Example 1 was carried out to isolate m-nitrophenol. Yield 7
, Ofi' (yield: 90%), 95-96°C, yellow crystals.

Example 3 The same operation as in Example 2 was performed except that allyl 0-nitrophenyl ether was used as the raw material. Yield Z3
2 (yield 96cm), bp, 9'4~96℃/20m
sHy, mp, 44-45°C.

Example 4 The same operation as in Example 2 was carried out except that allyl p-nitrophenyl ether was used as the raw material. Yield Z2
1 (yield 92%), mp, 112-114°C.

, Examples 5 to 9 As raw materials, allyl m-nitrophenyl ether, Pd
The table shows the results of the reaction using the catalyst and palladium chloride in the same manner as in Example 2, but with other people. Note that the yield determined from analysis by liquid chromatography is shown.

Procedural amendment (voluntary) June 1, 1985 Manabu Shiga, Commissioner of the Japan Patent Office1, Indication of the case 1985 Patent Application No. 793552, Title of invention: Process for producing nitrophenol 3゜Amendment case Relationship with Patent Applicant Address: 3-2-5-4 Kasumigaseki, Chiyoda-ku, Tokyo, "Detailed Description of the Invention" column 5 of the specification to be amended, Contents of the amendment 1) Description, page 2, U (org, 5y
ntb.

coel, J wo ``(Oi'nic, Shinsense. Collective (org, 5ynth, aoH,),'' is corrected.

2) Similarly, on page 2, line 15, “(Ger.Offe
n.

5) Similarly, on page 4, lines 5.8 to 9 and 17, "pd (,0H300)," is replaced with rpd (
OH3COO)2” is corrected.

Similarly, on page 4, line 11, I-(AngeW.

Ohem, j is corrected to ``(Ar&ew; Ohem, ],''.

5) Similarly, on page 4, lines 15-16, “(-Tetr
? -hedron Lett, , j
Tetrahedron.

Letters (Tetrahedron Lett,])
I am corrected.

The same (, page 5, lines 3-4: ``(J.Or9゜Ch
erTL, J is ``(Journal, Off 8 Organic, Chemistry (J, Org, ahem, L
Correct it with J.

7) Similarly, on page 5, line 7, change “trivalent phosphine” to “
Trivalent phosphine,” he corrected.

8) Similarly, on page 15, line 11, "rpd catalyst and palladium chloride" was changed to "balaji chloride (0Hs) 3 as a pd catalyst".
0PJ Toal f) wo ``phOH bag (0H3J20j
F'J Correct.

that's all

Claims (1)

[Claims] 1) Nitrophenol, which is characterized in that allyl nitrophenyl ether is cleaved using formic acid or a salt thereof in the presence of a catalytic amount of a palladium compound and a catalytic amount of a trivalent phosphine compound. Production method. 2) The method according to claim 1, wherein the allyl nitrophenyl ether is allyl m-nitrophenyl ether.