JPS6147830B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides compounds of the general formula () having a halogen atom at the ortho position of the nitro group. (In the formula, X represents a halogen atom, and n is 0 to 3
indicates an integer. ) Halogenonitrobenzene derivatives (excluding 2,3-dichloronitrobenzene)
and an alkali cyanide in an aprontic polar solvent or a basic solvent in the presence of cuprous chloride or cuprous chloride and a cupric salt (2) The present invention relates to a method for producing an O-nitrobenzonitrile derivative represented by the formula (wherein X and n are as shown above). In particular, it is preferable to use 0.05 to 1.0 parts by weight of N-methylpyrrolidone or N,N'-dimethylimidazolidone as the aprontic polar solvent per 1 part by weight of the halogenonitrobenzene derivative.

Conventionally, the method for substituting the halogen group of an aromatic halogen compound with a cyano group is to place the aromatic halogen compound in an aprotic polar solvent or a basic solvent.
A common method was to react an aromatic halogen compound with copper cyanide in an amount equal to or more than the same molar amount.

The present inventors believe that the cyano substitution reaction using copper cyanide not only requires expensive reagents but also makes it difficult to recover and reuse copper after the reaction. When we investigated the cyano substitution reaction with alkali cyanide in the presence of easily available cuprous chloride or cuprous chloride and cupric salt, we found that cuprous chloride was used as a raw material for 2-halogenonitrobenzene derivatives. The present invention has been completed based on the discovery that even when using 0.1 to 0.4 times the molar amount, 0-nitrobenzonitrile derivatives can be obtained from 2-halogenonitrobenzene derivatives at a yield equivalent to or higher than when copper cyanide is used. In particular, N-methylpyrrolidone or N,N'-dimethylimidazolidone is used as the aprotic polar solvent.
For 1 part by weight of halogenonitrobenzene derivative
When 0.05 parts by weight to 1.0 parts by weight is used, the selectivity of the reaction can be particularly improved, and the desired 0-nitrobenzonitrile derivative can be obtained in good yield.

The method of the present invention produces less copper waste than the method using copper cyanide. In addition, there is almost no loss of solvents such as N-methylpyrrolidone and N,N'-dimethylimidazolidone during the reaction, and they can be separated and recovered by distillation after the reaction and reused, making this solvent industrially suitable. It is a very advantageous solvent.

The halogenonitrobenzene derivatives used in the present invention include 2-chloronitrobenzene, 2,
4-dichloronitrobenzene, 2,5-dichloronitrobenzene, 2,3,4-trichloronitrobenzene, 2,3,4,5-tetrachloronitrobenzene, 2-bromonitrobenzene, 2,3-
Dibromonitrobenzene, 2,4-dibromonitrobenzene, 2,5-dibromonitrobenzene,
Those having a halogen atom at the ortho position of the nitro group, such as 2,3,4-tribromonitrobenzene, are used. Examples of halogen atoms include fluorine, chlorine, bromine and iodine.

As the alkali cyanide, for example, sodium cyanide or potassium cyanide, which can be obtained industrially at low cost, is used. Alkali cyanide is usually used in a molar range of 1.0 to 2.0 times the amount of the raw material 2-halogenonitrobenzene derivative, but there is no particular advantage in using it in excess, and 1.0 to 1.2 times is suitable in practice. be.

The amount of cuprous chloride used is usually 0.05 to 1.0 times the mole of the raw material 2-halogenonitrobenzene derivative, but in consideration of the cyanation reaction results and the price of cuprous chloride, it is practically 0.1 to 0.4. Double molar ratio is appropriate. Cuprous chloride is gradually oxidized in the air,
Although it is known that cuprous chloride becomes cupric salt, there is no need to particularly purify cuprous chloride in this reaction, and according to the inventor's experiments, cuprous salt coexists in cuprous chloride. It has been found that it is advantageous to allow the reaction to proceed more slowly. The cupric salt may be contained in cuprous chloride in an amount of 0 to 70 mol percent, preferably 0.5 to 30 mol percent.
As the cupric salt, cupric sulfate, cupric nitrate, cupric chloride, etc. may be added. The copper used is eluted from the recovered inorganic matter with hydrochloric acid, etc., and then processed using a conventional method.
It can be recovered and used as cuprous chloride.

As the basic solvent, pyridine etc. can be used, and as the aprotic polar solvent, dimethylformamide, diethylformamide, dimethylsulfoxide, dimethylacetamide, hexamethylphosphoramide, N-methylpyrrolidone, N,
N'-dimethylimidazolidone, tetramethylene sulfone, dimethyl sulfone, etc. are used.
In particular, 2-
Good results can be obtained when 0.05 to 1.0 parts by weight are used per 1 part by weight of the halogenonitrobenzene derivative.

The reaction temperature and reaction time vary depending on the type and amount of the solvent used, but generally the reaction temperature is suitably 100 to 220°C, preferably 140 to 200°C. A suitable reaction time is 0.5 to 15 hours.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 19.2 g of 2,4-dichloronitrobenzene, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 5.44 g of sodium cyanide, and 4.0 g of N,N'-dimethylimidazolidone were added, and the reaction temperature was 170 g. The reaction was carried out at ℃ for 8 hours. After the reaction is complete, add 50ml of dichloroethane,
Inorganic substances were filtered out. After washing the filtrate with 5% aqueous ammonia and water, the organic layer was quantified by gas chromatography to obtain 3-chloro-6-nitrobenzonitrile in a yield of 78.7%.

Comparative Example 1 19.2 g of 2,4-dichloronitrobenzene, 10.0 g of copper cyanide, and 3.0 g of N-methylpyrrolidone were added, and the mixture was reacted at a reaction temperature of 170° C. for 4 hours. Post-treatment was carried out in the same manner as in Example 1 to obtain 3-chloro-6-nitrobenzonitrile in a yield of 59.5%.

Example 2 19.2 g of 2,4-dichloronitrobenzene, 5.44 g of sodium cyanide, 4.0 g of cuprous chloride, and 3.0 g of pyridine were added, and the mixture was reacted at a reaction temperature of 170° C. for 4 hours. Post-processing was performed in the same manner as in Example 1,
3-chloro-6-nitrobenzonitrile was obtained with a yield of 34%.

Example 3 2-chloronitrobenzene 23.6g, cuprous chloride
4.8g, anhydrous cupric sulfate 2.0g, sodium cyanide 8.16g and N,N'-dimethylimidazolidone
4.5g was added and the reaction was carried out at a reaction temperature of 170°C for 4 hours. Post-treatment was performed in the same manner as in Example 1, and the yield was
2-nitrobenzonitrile was obtained at 76.3%.

Example 4 2-chloronitrobenzene 23.6g, cuprous chloride
4.8 g of anhydrous cupric sulfate, 2.0 g of anhydrous cupric sulfate, 8.16 g of sodium cyanide, and 4.5 g of N-methylpyrrolidone were added, and the mixture was reacted at a reaction temperature of 180° C. for 4 hours. Post-treatment was carried out in the same manner as in Example 1, and 2 was obtained with a yield of 67.1%.
- Obtained nitrobenzonitrile.

Comparative example 2 2-chloronitrobenzene 23.6g, copper cyanide
Add 15.0g and 4.5g of N-methylpyrrolidone,
The reaction was carried out at a reaction temperature of 180°C for 4 hours. Post-treatment was performed in the same manner as in Example 1 to obtain 2-nitrobenzonitrile in a yield of 20.6%.

Example 5 19.2 g of 2,5-dichloronitrobenzene, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 5.44 g of sodium cyanide, and 3.0 g of N,N'-dimethylimidazolidone were added, and the reaction temperature was 170°C. The mixture was allowed to react for 8 hours. Post-treatment was performed in the same manner as in Example 1, and the yield was
4-chloro-6-nitrobenzonitrile was obtained at 61.4%.

Example 6 2,3,4-trichloronitrobenzene 17.0
g, 2.4 g of cuprous chloride, 1.0 g of anhydrous cupric sulfate, 4.1 g of sodium cyanide, and 2.3 g of N-methylpyrrolidone were added, and the mixture was reacted at a reaction temperature of 170° C. for 4 hours. Post-treatment was performed in the same manner as in Example 1 to obtain 2,3-dichloro-6-nitrobenzonitrile in a yield of 88.6%.

Example 7 28.1 g of 2,3-dibromonitrobenzene, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 5.44 g of sodium cyanide, and 4.0 g of N,N'-dimethylimidazolidone were added, and the reaction temperature was 160°C. The mixture was allowed to react for 4 hours. Post-treatment was performed in the same manner as in Example 1 to obtain 2-bromo-6-nitrobenzonitrile in a yield of 75.3%.

Example 8 28.1 g of 2,5-dibromonitrobenzene, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 5.44 g of sodium cyanide and 4.0 g of N-N'-dimethylimidazolidone were added, and the reaction temperature was 160°C. The mixture was allowed to react for 4 hours. Post-treatment was performed in the same manner as in Example 1 to obtain 4-bromo-6-nitrobenzonitrile in a yield of 70.6%.

Example 9 19.2 g of 2,4-dichloronitrobenzene, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 7.22 g of potassium cyanide, and 4.0 g of N,N'-dimethylimidazolidone were added, and the reaction temperature was 170°C. The mixture was allowed to react for 8 hours. Post-treatment was performed in the same manner as in Example 1 to obtain 3-chloro-6-nitrobenzonitrile in a yield of 76.3%.

Example 10 2,4-5-tribromonitrobenzene 36.0
g, 3.2 g of cuprous chloride, 1.3 g of anhydrous cupric sulfate, 5.44 g of sodium cyanide, and 4.0 g of N,N'-dimethylimidazolidone were added, and the reaction temperature was 160°C.
Allowed time to react. Post-treatment was carried out in the same manner as in Example 1 to obtain 3,4-dibromo-6-nitrobenzonitrile in a yield of 85.2%.

Example 11 2,4,5-tribromonitrobenzene 36.0g
37.5g of 2,3-diiodonitrobenzene instead of
The reaction and post-treatment were carried out in the same manner as in Example 10, except that 2-iodo-6-nitrobenzonitrile was obtained in a yield of 83.5%.

Example 12 2,4,5-tribromonitrobenzene 36.0g
2,4-difluoronitrobenzene instead of 15.9
The reaction and post-treatment were carried out in the same manner as in Example 10 except that 3-fluoro-6-
Nitrobenzonitrile was obtained.

Example 13 Add 19.2 g of 2,4-dichloronitrobenzene, 4.0 g of cuprous chloride, 5.44 g of sodium cyanide and 4.0 g of N,N'-dimethylimidazolidone,
The reaction was carried out at a reaction temperature of 170°C for 8 hours.

Post-treatment was performed in the same manner as in Example 1, and the yield was
3-chloro-6-nitrobenzonitrile was obtained at 77.8%.

Example 14 19.2 g of 2,4-dichloronitrobenzene, 3.2 g of cuprous chloride, 0.8 g of cupric chloride, 5.44 g of sodium cyanide, and N,N'-dimethylimidazolidone
4.0g was added and the reaction was carried out at a reaction temperature of 170°C for 8 hours. Post-treatment was performed in the same manner as in Example 1, and the yield was
3-chloro-6-nitrobenzonitrile was obtained at 78.4%.

Claims (1)

[Claims] 1 General formula () having a halogen atom at the ortho position of the nitro group (In the formula, X represents a halogen atom, and n is 0 to 3
indicates an integer. ) A halogenonitrobenzene derivative (excluding 2,3-dichloronitrobenzene) and an alkali cyanide are mixed with cuprous chloride or cuprous chloride in an aprotic polar solvent or basic solvent. General formula () characterized by reacting with and in the presence of a cupric salt A method for producing an O-nitrobenzonitrile derivative represented by the formula (wherein X and n are as shown above).