JPS61197546A - Production of 3,3'-dinitrodiphenyl ether - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a raw material for agricultural chemicals and drugs easily in high purity and in high yield, by subjecting inexpensive meta-dinitrobenzene to self-condensation reaction in the presence of a base and a catalytic amount of meta-nitrophenol in an aprotic polar solvent. CONSTITUTION:Meta-nitrobenzene is subjected to self-condensation reaction in the presence of a base (e.g., potassium carbonate, potassium hydroxide, NaOH, etc.) and a catalytic amount of meta-nitrophenol in an aprotic polar solvent (e.g., 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoramide, etc.) to give 3,3'-dinitrodiphenyl ether. Since this method has high conversion ratio to the aimed substance and high selectivity, it is economical. This process has further easy purification, and is industrially preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention comprises 3. ;'-Relating to a novel method for producing dinitrodiphenyl ether.

More specifically, the 3,5'-
The present invention relates to a method for producing dinitrodiphenyl ether.

3.3'-Dinitrodiphenyl ether is an intermediate for 3,3'-diaminodiphenyl ether, which is a raw material for agrochemicals and medicines, and is also a raw material for boria ε-do, polyamideimide, and polyimide.

(Prior art) 3. s'-dinitrodiphenylniterha, conventionally,
U of metanitrophenol and metabromonitrobenzene
A method of producing by l1mann reaction is known (
Tomita et al., Pharmaceutical Journal, 751080 (1955),
Benyo et al., Pharmaceutical Journal, 79273 (1959),
J, P, Crlt-chley et al., T, Polyme
r, Sci,, part A-1101795 (1
797) ).

(Problems to be solved by the invention) However, these methods have drawbacks such as low yields and the risk of explosion, and furthermore, the raw materials are too expensive to carry out industrially. The biggest drawback is that it is not easy to obtain.

(Another Means to Solve the Problem) The present inventors have intensively studied methods for producing 3,3'-dinitrodiphenyl ether at low cost and industrially. First, we discovered a method using stoichiometric amounts of metadinitrobenzene and metanitrophenol, and a method of self-condensing methadinitrobenzene in the presence of nitrite.Furthermore, as a result of intensive studies on the reaction of metadinitrobenzene, we discovered that metadinitrobenzene was The present invention was completed based on the discovery that the entire self-condensation reaction can proceed in the presence of a base and a catalytic amount of meta-nitrophenol.

That is, the present invention is characterized in that methadinitrobenzene is subjected to a self-condensation reaction in an aprotic polar solvent in the presence of a base and a catalytic amount of metanitrophenol.
- A method for producing dinitrodiphenyl ether.

The method of the present invention involves first condensing a catalytic amount of metanitrophenol alkali metal with metadinitrobenzene;
In this method, the generated nitrite sequentially leads metadinitrobenzene to a self-condensation reaction. Therefore, in addition to self-condensation of metadinitrobenzene, the desired product can also be derived from any catalytic amount of metanitrophenol.

An example of producing ethers by the self-condensation reaction of nitro compounds is 4-nitro-N-methylphthalimide.
．． Method for producing 4'-oxybis(N-methylphthalimide) (R,J, Markezich et al.

J, ○rg, Chem,, 423431-3434 (
1977) ), 4-nitrohenzonitrile to 4.
Method for producing 4'-dicyanodiphenyl ether (E
, Helnz et al.

Ger of fen,, 2.037.781)
etc.

However, all of these reactions involve an active nitro group having an electron-withdrawing group at the P-position, and reactions involving an inert nitro group having an electron-withdrawing group at the m-position are unknown.

Further, there is no known example of a self-condensation reaction of a compound having multiple nitro groups on the same nucleus.

The method of the present invention in which metadinitrobenzene is subjected to a self-condensation reaction with nitrite as a by-product using nitrophenol as a catalyst is a novel reaction.

The base used in the method of the invention is an alkali metal carbonate, hydrogen carbonate, hydroxide or alkoxide, specifically potassium carbonate, sodium carbonate, potassium hydrogen carbonate, potassium hydroxide, sodium hydroxide. , sodium methoxide, potassium impropoxide, and the like.

The amount of these bases to be used may be at least equivalent to J:metanitrophenol used as a catalyst, and specifically, it may be from 1 to 10 equivalents.

As the solvent used in the method of the present invention, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoramide are preferably used, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl Pyrrolidone, dimethyl sulfoxide, sulfolane, etc. can also be used.

The amount of these solvents used is not particularly limited, but usually
The amount is 1 to 15 times, preferably 3 to 10 times the weight of the raw material.

Further, in the method of the present invention, a phase transfer catalyst such as copper powder or a copper-based compound, or a crown ether, polyethylene glycol, quaternary ammonium salt, or quaternary phosphonium salt is used as a catalyst to promote the reaction. There is nothing wrong with that either.

The reaction temperature is usually in the range of 100 to 240°C,
Preferably, the temperature is in the range of 140 to 200°C.

In a general embodiment of the present invention, a predetermined amount of metanitrophenol, a base, and a solvent are charged, metanitrophenol is converted into an alkali metal salt, and then methadinitrobenzene is added and reacted, or, It is also possible to add all the raw materials containing metadinitrobenzene at the same time in advance, and then to raise the temperature and allow the reaction to occur.

Of course, the present invention is not limited to these examples, and may be implemented in other ways as appropriate.

When water is generated in the reaction system, there is a method to remove it by passing nitrogen gas etc. to gradually discharge it out of the system during the reaction, but in general, benzene, toluene, xylene, and chlorobenzene are removed. A method is often used in which a small amount of acetate is used to remove it from the system by azeotropy.

The end point of the reaction can be determined by thin layer chromatography, high performance liquid chromatography, or gas chromatography while observing the decrease in raw materials.

After the reaction is completed, the residue is concentrated or directly discharged into water to obtain crude 3,3'-dinitrodiphenyl ether. This product can be easily purified by recrystallization using a solvent.

(Functions and Effects) According to the method of the present invention, a catalytic amount of methane nitrobenzene can be produced using extremely inexpensive methane nitrobenzene as a raw material.

Furthermore, since this method has a high conversion rate and selectivity to the target product, it is not only more economical, but also easy to purify and is suitable as an industrial manufacturing method because it can produce high-purity products with good yield. It is.

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

Example 1 Metanitrophenol 702 (0.05 mol) was added to a reactor equipped with a stirrer, a thermometer, a reflux condenser and a water separator.
, 96 kalium potassium hydroxide 2.921i' (0.05 mol), benzene", Oml and 1.ro-dimethyl-2
-imidazolidinone somg was charged, and water that azeotroped under the reflux state of benzene was removed from the system while stirring. After complete azeotropic dehydration, the temperature was lowered to 60°C and 84 ml (0.5 mol) of metadinitrobenzene was added.Next, the temperature was raised to 17°C while bubbling nitrogen gas.
The temperature was kept at 0 to 180°C and the reaction was carried out for 18 hours.

After the reaction was completed, the solvent was recovered by concentration under reduced pressure, and the remaining tar-like substance was discharged into 500 ml of water.

When stirring was continued, small brown crystals formed.

After filtering and drying this, it was reconstituted with benzene. (yield 548%) of 6.3'-
Obtain dinitrodiphenyl ether.

This product was recrystallized with ethyl acetate to obtain a pure product of slightly brown prismatic crystals.

The melting point was 127-128°C, and the results of elemental analysis were as follows.

HN Calculated value (%) 55,39 3.10 10.
77 Measured value (%) 55,12 3.31 1
0.71 Example 2 Into a reactor equipped with a stirrer and a thermometer, 20.99 (0.15 mol) of metanitrophenol, 84 y (0.5 mol) of metadinitrobenzene, and 138 g (138 g) of anhydrous potassium carbonate were added.
0.1 mol), copper powder 03L? and 350 ml of hexamethylphosphoramide were charged, and the temperature was raised by bubbling nitrogen gas while stirring. The reaction was completed by maintaining the temperature at 180-190°C for 8 hours.

Post-treatment after the completion of the reaction was carried out in the same manner as in Example 1.
61 (yield 63.3%), 3'-dinitrodiphenyl ether was obtained.

Example 3 The procedure of Example 1 was repeated except that the base was replaced with 2.79 (0.05 mol) of sodium methoxide and methanol was distilled off together with benzene.
5%) +7) 3.3'-dinitro diphenyl ether was obtained.

Example 4゜The base was 11M sodium carbonate? (0.1 mol) was carried out in the same manner as in Example 2, yielding 50.39 (yield $5
9.5%) of 3,3'-sinitron phenyl ether was obtained.

Example 5゜ Metanitrophenol 20.9 was added to the same apparatus as Example 1.
P (0.15 mol), 6 g of sodium hydroxide (0.1
5 moles), 50 ml of benzene, and 500 ml of N,N-dimethylformamide were charged, and water that azeotroped under the reflux state of benzene was removed from the system while stirring. After complete azeotropic dehydration, the temperature was lowered to 60° C. and metadinitrobenzene 847 (0.5 mol) was added. The subsequent operations are performed in the same manner as in Example 1, and S4B? (Yield 41
2%) of 69'-dinitrodiphenyl ether was obtained.

Claims (1)

[Claims] 1) A method for producing 3,3'-dinitrodiphenyl ether, which comprises subjecting metadinitrobenzene to a self-condensation reaction in an aprotic polar solvent in the presence of a base and a catalytic amount of metanitrophenol.