JPS5913749A - Preparation of 4-trifluoromethyl-4'-nitrodiphenyl ether compound - Google Patents

Abstract

PURPOSE:To prepare the titled compound useful as a herbicide, in high yield, by reacting bis-4-trifluoromethylphenyl carbonate compound with 4-chloronitrobenzene compound in an inert organic solvent in the presence of an alkali metal (bi)carbonate. CONSTITUTION:The objective compound of formula III can be prepared by reacting the bis-4-trifluoromethylphenyl carbonate compound of formula I (X is H or Cl) with the 4-chloronitrobenzene compound of formula II [Y is H, OR, COOR, CONHR, or CON(R)2 (R is lower alkyl)] in an inert organic solvent (e.g. DMF) in the presence of an alkali metal carbonate (e.g. potassium carbonate) or bicarbonate. When the reaction is carried out using 1.0-5.0 mol of the alkali metal compound per 1mol of the compound of formula II, at 100-150 deg.C for about 10-40hr, the ratio of by-product can be decreased and the objective compound can be prepared in high purity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing diphenyl ether u from bisphenyl carbonates and chlorobenzenes, in which the target compound 4-)IJ fluoromethyl-4'-nitrodiphenyl ether is It is known as a compound useful as a herbicide.

Conventionally, the following two methods are generally known as methods for producing diphenyl ethers.

・・・・・・・・・・・・(Ml For example, method (1) is disclosed in JP-A-49-256, but 4-trifluoromethylphenol is easily polymerized in the presence of alkali. However, it is difficult to suppress side reactions, so the purity and yield of the target product are extremely low.

Also, the method (!l) is described in the Journal of Agr.
cultural and food chemist
ry Vol. 26, p. 285 (1978), and various derivatives can be obtained by further esterification or amidation. However, this method has many problems that are inconvenient for industrialization, such as 2) producing a large amount of isomers other than the desired product in the o-conversion reaction step, and there is an urgent need to establish an advantageous production method.

As a result of intensive research to overcome these problems, the present inventors have succeeded in producing high-purity nosiphenyl ethers from bisdiphenyl carbonates and tochlorobenzenes on an industrial scale with dynamic K and high yield. A new manufacturing method was discovered and the present invention was completed.

That is, the present invention provides bis-4-trifluoromethylphenyl carbonates represented by the general formula (wherein, X represents a hydrogen atom or a chlorine atom), 0R1-COOR1-CON
HRl-CON(R12 (R is a lower alkyl group)
Indicates the group. A general formula characterized by reacting 4-chloronitrobenzene represented by ] in an inert organic solvent in the presence of an alkali metal carbonate or bicarbonate.

4-trifluoromethyl-4 (X and Y have the same meanings as in general formulas (1) and (2))
This is a method for producing '-nitrodiphenyl ethers.

Bis- represented by general formula (1) used in the method of the present invention
Examples of 4-trifluoromethylphenyl carbonates include bis-4-trifluoromethylphenol carbonate ($-) and bis-(2-/chloro-4-trifluoromethylphenyl) carbonate.

Further, R representing the lower alkyl group of the substituent Y of the 4-chloronitrobenzene represented by the general formula (2) has 1 to 4 carbon atoms.

Specifically, 4-chloronitrobenzene, 3-methoxy-4-nitrochlorobenzene, 3-ethoxy-4-nitrochlorobenzene, 4-nitro-5-70
biloxychlorobenzene, 3-1-propyloxy-4-nitrochlorobenzene, 5-7') xy-4-nitrolobenzene,! 1-i
-7') xy-4-nitrochlorobenzene, 3-s
-1) xy-4-nitropolylobenzene, 5-1-b)
xy-4-nitrochlorobenzene.

5-chloro-2-nitrobenzoic acid methyl ester, 5-chloro-2-nitrobenzoic acid methyl ester, 5-chloro-2-nitrobenzoic acid propyl ester, 5-rioo2-nitrobenzoic acid-1 -7"lopyl ester, 5-100-2- 2) o benzoill glutyl ester, 5- / o o + 2-nitrobenzoic acid-toro-butyl ester, 5-rioaQ-nitrobenzoic acid-5-butyl ester , 5-chloror:1-2-nido-abenzoic acid-t-glythyl ester, N-methyl-5-chloro-2-nitrobenzoic acid amide, N-ethyl-5-chloro-2-nitrobenzoic acid Amide, N-propyl-5-chloro-2-nitrobenzoic acid amide
N-1-propyl-5-chloro-2-nitrobenzoic acid i)''.

N-butyl-5-chloro-2-nitrobenzoic acid amide, N-1-7'thyl-5-chloro-2-nitrobenzoic acid ido, N-s-phthyl-5-/chloro-2-nitro Benzoic acid amide, N-t-butyl-5-chloro-2-nitrobenzoic acid amide, N,N-di)thyl-5-chloro-2-nitrobenzoic acid amide.

N,N-diethyl-5-chloro-2-nitrobenzoic acid amide, N,N-di'jroby-5-chloro-2-nitrobenzoic acid ido, N,N-di-1-propyl-5- Chloro-2-nitrobenzoic acid amide.

N,N-diptyl-5-chloro-2-nitrobenzoic acid i.

N,N-di-I-butyl-5-chloro-2-nitrobenzoic acid amide, N,N-di-S-butyl-5-chloro-2-nitrobenzoic acid ido, N,N-di-1- Examples include butyl-5-chloro-2-nitrobenzoic acid amide.

These bis-4-trifluoromethylphenyl carbonates and 4-chloronitrobenzenes can be easily synthesized by known methods.

Method 1c1 of the present invention! ! As the inert organic solvent to be used, dimethylformamide, dimethylsulfoxide, sulfolane, dimethylacetamide, etc. are preferable, taking into consideration the maintenance of the degree of 1 reaction group, activation of the reaction reagent, etc.

The amount of solvent used is suitably 2 to 20 times the weight of the 4-chloronitrobenzenes, preferably 3 to 10 times the amount by weight.

As the alkali metal compound, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate are used, and potassium carbonate is particularly preferred. The amount of alkali metal compounds used is 4-chloronitrobenzenes 1
1.0 to 5, . A suitable range is 0 mol, preferably 1.0 to 2.0 mol.

4-chloronitrobenzenes Tohis-4-) Use with IJ fluoromethylphenyl carbonates! 'J
1 mol of 4-chloronitrobenzenes to 4-) of 4-chloronitrobenzenes 0 fluoromethylphenyl carbonates
．． 5 to 0.7 mol is appropriate, preferably α50 to α
It is 60 moles.

Since the reaction with 4-chloronitrobenzenes and tohis-4-trifluoromethylphenyl carbonates does not require the presence of water, it is necessary to remove as much water as possible from the reaction system. As a method for removing water, after charging an inert organic solvent and an alkali metal compound into a reactor, benzene,
It is preferable to perform azeotropic distillation by adding a solvent such as toluene that is azeotropic with water.

Next, after distilling off the excess azeotropic solvent, 4-chloronitrobenzenes and tobis-4-trifluoromethylphenyl carbonates are charged and a reaction is carried out. Alternatively, water may be distilled off while the reaction proceeds without benzene or toluene being distilled off.

The reaction temperature is preferably in the range of 100 to 150°C. More preferably, the temperature is 100 to 120°C.

At temperatures below 100°C, the etherification reaction rate is slow and it takes a long time to complete the reaction. If the temperature is 150° C. or higher, the proportion of by-products produced increases, resulting in low yield and purity.

The reaction time varies mainly depending on the reaction temperature and the type of reagent used, but is about 10 to 40 hours.

In the reaction with 4-chromitrobenzenes tohis-4-) IJ fluoromethylphenyl carbonates, the presence of oxidizing substances increases the rate of by-product formation, so the reaction is carried out under an inert gas stream of nitrogen, helium, argon, etc. It is best to do it inside.

After the reaction is completed, if necessary, the solvent is recovered by distillation under reduced pressure.
The desired diphenyl ether compound can be separated by pouring the residue into water.

Alternatively, the diphenyl ether compound may be separated by extraction using water or a water-insoluble solvent such as benzene or toluene.

According to the method of the present invention, a highly purified diphenyl ether compound can be obtained in a high yield, so that the crude product can usually be used as is for the intended purpose.

Hereinafter, the present invention will be specifically explained and explained by examples.

Example 1 Potassium carbonate 2aO in 200r dimethylformamide
Add r (202 mmol) and benzene 1501,
A water separator and a nitrogen inlet pipe were attached, and after replacing the air dissolved in the solvent and the air in the reactor with nitrogen, water in the reaction system was azeotropically distilled off under a nitrogen atmosphere. Furthermore, after distilling off benzene, bis-(2-10-4-)IJ fluoromethylphenyl) carbonate 24r (57 mmol)
and 103 mmol of 5-chloro-2-nitrobenzoic acid-1-propyl ester (25FC) were added thereto, and the mixture was stirred at 110° C. for 14 hours in a nitrogen stream. After cooling, the mixture was poured into a 2% aqueous sodium hydroxide solution in a reactor, stirred at room temperature for about 15 minutes, and then the insoluble materials were removed. Dry after washing with water 37
．． 5F 5-[2-chloro-4-()IJ fluoromethyl)phenoxyf-nitrotrobenzoic acid-1-propyl ester was obtained in a yield of 90.1%. Purity by gas chromatography was 97.8%, 0 point 55-55°C.

Example 2 Potassium carbonate 14,5 in dimethylformamide 70
FC (105 mmol) and 50 r of benzene were added, a water separator and a nitrogen inlet tube were attached, and water in the reaction system was azeotropically distilled off in a nitrogen stream. Bis-(2-chloro-4-)
IJ fluoromethylphenyl)carbonate) 15.4
PC37 mmol) and N-methyl-5-chloro-2
-Nitrobenzoic acid 15. OF (70 mmol) was added and the solution was heated under azeotropic dehydration with benzene in a nitrogen stream for 1
The mixture was stirred at 20°C for 25 hours. After cooling, the reaction mixture was reduced to 2%
It was poured into an aqueous sodium hydroxide solution and extracted using benzene. After washing the benzene layer with water, it was dehydrated with anhydrous sodium sulfate and the solvent was removed by distillation under reduced pressure to remove 2&9rN.
-1+ru5-(2-chloro-4-(trifluoromethyl)phenoxif-2-nitrobenzoic acid amide was obtained in a yield of 91.2%. (Purity 97.4%, melting point 116-1
19°C) Example 6 Potassium carbonate 37F in 500r dimethyl sulfoxide
(268 mmol) of 50 liters of dichloromethane was added, a water separator and a nitrogen inlet tube were attached, and water in one reaction system was azeotropically distilled off in a nitrogen stream. Furthermore, after distilling off benzene, bis-(
4-trifluoromethylphenyl) carbonate 2 & 3
R (75 mmol) and 30.2 r (150 mmol) of 6-nitoxy-4-nitroxybenzene were added, and the mixture was stirred at 120° C. for 11 hours in a nitrogen stream. After cooling,
The reaction mixture was poured into water to remove insoluble matter. After washing with water and drying, 43.1r of 3-ethoxy-4-nitro-4'-)
IJ fluoromethyl diphenyl ether yield 87.8
Obtained in %. (Purity 9a1%, melting point 72-74°C) Example 4 Potassium carbonate 10F in dimethylformamide 55'y
(72 mmol) and 30 tons of benzene were added, a water separator and a nitrogen introduction tube were attached, and water in the reaction system was azeotropically distilled off in a nitrogen stream. Furthermore, after distilling off benzene, bis-(2
-Chloro-4-trifluoromethylphenyl) 9.2r (22 mmol) and p-nitrochlorobenzene&3r (40 mmol) were added, and the mixture was stirred at 100°C IC in a nitrogen stream for 28 hours. After the reaction was completed, dimethylformamide was distilled off under reduced pressure, and the residue was added to water and stirred for about 10 minutes. The insoluble matter was washed in a separate furnace with water and then dried to obtain 11.2F 2-chloro-4-trifluoromethyl-4'-nitrodiphenyl ether in a yield of 8% and 2%. (Purity 97.6%, melting point 68-71°C) Example 5 Potassium carbonate 17r (
125 mmol) and benzene 30F were added, a water separator and a nitrogen inlet tube were attached, and water in the reaction system was azeotropically distilled off in a nitrogen stream. After further distillation of benzene, bis-(2
-chloro-4-trifluoromethylphenyl)carbonate) 1&8F (40 mmol) and 5-ethoxy-4
-Nitrochlorobenzene i 4.7 r (75 mmol) All charges were stirred at 110°C for 25 hours. After the reaction was completed, the reaction mixture was poured into water, and the insoluble materials were washed with water and dried.
g, 251r 2-chloro-4-trifluoromethyl-
6'-Ethoxy-4'-nitrodiphenyl ether was obtained in a yield of 87.5%. (Purity 9a2%, weight 82-84
℃) Example 6 1 part potassium bicarbonate in 110 parts dimethylformamide
41F (140 mmol) and 40 rft of benzene were added, a water separator and a nitrogen introduction tube were attached, and water in the reaction system was azeotropically distilled off in a nitrogen stream. Furthermore, after distilling off benzene,
Bis-(2-chlorolff-4-trifluoromethylphenyl)carbonate 2[16P (49 mmol)
and 6-Medoxy 4-Nitrok oral benzene 1!5
．． A total of 4F (82 ('J mol)) was charged and stirred at 125°C for 26 hours. After the reaction was completed, the reaction mixture was poured into a 2% aqueous sodium hydroxide solution, and the insoluble matter was washed with water in the furnace and then dried. r(71)2-/chloro4-) IJ fluoromethyl-3'-methoxy-4'-nitrodiphenyl ether was obtained in a yield of 84.6%. (Purity 96.4%,
Melting point 9&~101°C) Example 7 Dimethylformamide 50r3 Sodium carbonate 15F (
141 mmol) and toluene Sat were added, a water separator and a nitrogen inlet tube were attached, and water in the reaction system was azeotropically distilled off in a nitrogen stream. Furthermore, after distilling off toluene, bis-(2
-chloro-4-trifluoromethylphenyl) carbonate 90t (21# 17 mol) and p-nitrochlorobenzene 5.7 r (36 mmol) were added to 125
The mixture was stirred at ℃ for 24 hours. After the reaction was completed, the solvent was distilled off under reduced pressure, and the residue was extracted using toluene. 5 layers of toluene
After washing with % sodium hydroxide aqueous solution, dehydration with sodium sulfate and distilling off toluene (9.5 t O)
2-/chloro4-) IJ fluoro-l-4'
-Nitrodiphenyl ether was obtained in a yield of 856%. (
Purity 96.2%, melting point 67-70℃) Hodogaya Chemical Industry Co., Ltd.
'l Display Showa 574 ■Special;'rlPj No. 120529 No. 2
Name of the invention 4 bit 4-1 refluorinated methyl 4゛-2] ronobenyl eno-y-not t1. ．． ．． q's production J Lean,・Last 3,）City 11:Relationship with Sekushi Ino 1Special↓'1tlllf Address: Toranomon, Minato-ku, Tokyo-T 4-2-
11, +-1- 5. Contents of amendment (1) Page 1.1, first line (7) I-100-120
'Correct CJ to rloO~125°CJ.

(2) Correct ``water, or to water'' in the 16th item of the same page to ``water'' and ``water'' to J by δJ.

(3) ff month page 4, line I rl 16-119'CJ
is corrected to r136-139° (j.

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Scope of Claims] Bis-4-trifluoromethylphenyl carbonates represented by the general formula (wherein, X represents a hydrogen atom or a chlorine atom); is a hydrogen atom, -OR, -COOR. -CONHR, -CON(R), (R represents a lower alkyl group) group. ] in an inert organic solvent in the presence of an alkali metal carbonate or bicarbonate. 4-trifluoromethyl-
An method for 4'-nitrodiphenyl ethers.