JPS6228945B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to nitration of anthraquinones in the coexistence of halogenated aliphatic hydrocarbons, and then recovery of the halogenated aliphatic hydrocarbons. Halogenation is achieved by intermittently or dropwise injecting the nitration reaction liquid into the water maintained at a temperature above the azeotropic point of water and water, and instantly cooling and separating the azeotropic fraction. The present invention relates to a method for recovering aliphatic hydrocarbons.

Various methods are known for the nitration of anthraquinone, but a method for selectively introducing a nitro group into the α-position of anthraquinone is described in Japanese Patent Application Laid-open No. 49-1999.
Nitration in the coexistence of halogenated aliphatic hydrocarbons is described in No. 55654 or JP-A-52-39663. When the present inventors conducted additional tests, the effects of halogenated aliphatic hydrocarbons were indeed recognized, so they investigated a method for recovering halogenated aliphatic hydrocarbons and completed the present invention.

Halogenated aliphatic hydrocarbons are highly volatile;
It is also highly toxic, so it is essential to recover it.

Normally, in this type of reaction such as the nitration reaction of anthraquinone, the reaction mass after the reaction is
Generally, the target product is discharged into water, the precipitate of the desired product is separated into solid and liquid, and the solvent is recovered from the filtrate by distillation. However, when a halogenated aliphatic hydrocarbon is used as a solvent, it has an affinity for nitroanthraquinone, so after the reaction is complete, it is discharged into water and separated into solid and liquid. Since it is adsorbed, it is necessary to separate it in the slurry state before solid-liquid separation.

The present inventors attempted to recover the solvent by discharging the anthraquinone nitration reaction solution into water and increasing the temperature of the discharged solution without separation, but foaming was so severe that it was impossible to carry out the experiment. Attempts were also made to extract halogenated aliphatic hydrocarbons by adding other organic solvents to the effluent, but this was found to be uneconomical as it required dissolution loss of nitroanthraquinones or separation and purification of the organic solvent.

In view of the above-mentioned circumstances, the present inventors placed the nitration reaction solution in water kept at a temperature higher than the azeotropic point of water and the halogenated aliphatic hydrocarbon used in the nitration reaction. By intermittent injection or dripping, halogenated aliphatic hydrocarbons are instantaneously applied to the surface of the water.
It has been found that halogenated aliphatic hydrocarbons can be recovered very easily by azeotropic evaporation with water and immediate distillation from the effluent to prevent foaming.

The anthraquinone used in the present invention may have a halogen atom, hydroxyl group, alkyl group, allyloxy group, acylamino group, etc. as a substituent.

Nitration of anthraquinones is usually carried out with a mixed acid, and mononitration or dinitration reactions of the anthraquinone nucleus are considered. However, when an allyloxy group is included as a substituent, the nitration reaction of the allyl nucleus of allyloxy must also be taken into consideration.

Although it is possible to extract the anthraquinone nitration reaction liquid as it is into hot water, the anthraquinone nitration reaction liquid diluted with water or the like may be discharged into hot water. The water may be just water or dilute sulfuric acid.

The halogenated aliphatic hydrocarbons used together with the nitration reaction include those having 1 to 3 carbon atoms substituted with 1 to several halogens (fluorine, chlorine, and bromine).
saturated aliphatic hydrocarbons. Specifically, methylene chloride, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2
-tetrachloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,2,3
-Compounds such as trichloropropane, methylene bromide, bromoform, and 1,2-dibromoethane can be mentioned. In particular, 1,1-dichloroethane, 1, which has a high affinity with nitroanthraquinone,
2-dichloroethane, 1,1,2,2-tetrachloroethane, 1,2-dichloropropane, 1,
When dichlor having 2 to 3 carbon atoms, such as 1,2-trichloroethane and 1,2,3-trichloropropane, or trichlorohalogenated aliphatic hydrocarbons are used in the reaction, the solvent can be effectively recovered. In such a case, the temperature in the water will vary slightly depending on the azeotropic temperature, but it is preferably in the range of 70 to 100°C. There is no particular limitation on the amount of these used during the nitration reaction.

By the method of the present invention, halogenated aliphatic hydrocarbons can be easily recovered in high yield and recycled. Note that the quality and yield of nitroanthraquinones are not affected by this operation.

Next, the method of the present invention will be specifically explained using examples.

Example 1 A mixed acid consisting of 68.4 ml of 98% (by weight, same hereinafter) nitric acid and 85.2 ml of 100% sulfuric acid was boiled under reflux in a 1 volume flask equipped with a stirrer, thermometer, reflux condenser and dropping funnel. The solution was added slowly dropwise over a period of about 150 minutes to a mixture of 200 ml of methylene chloride and 250 g (1.2 moles) of anthraquinone (99%). Subsequently, the mixture was stirred at the same temperature for 4 hours and then cooled to room temperature. The reaction mixture was then kept at 60°C.
It was poured intermittently into 500 ml of water over 100 minutes, and the organic solvent was recovered by distillation. The remaining aqueous suspension was filtered and the mass was washed with water until neutral and dried.

Yield: 299g. 1-Nitroanthraquinone content
77%, yield 77%.

The azeotropic temperature of methylene chloride and water is 38.1℃.
The amount of methylene chloride recovered was 180 ml.

Example 2 Anthraquinone 20.8 with a particle size of 150 mesh or less
Add 62.4 g of 90% sulfuric acid and 5.2 g of methylene chloride to g, stir well, cool and keep warm at 15℃ to dissolve 98% nitric acid.
8.32g was added over 1 hour. The mixture was further stirred at this temperature for 24 hours to complete the nitration reaction. The nitration mixture was then diluted to a 70% sulfuric acid concentration by dropwise addition of 50% sulfuric acid, and this was heated at 500 °C maintained at 70 °C.
methylene chloride was recovered by distillation, and the remaining aqueous suspension was filtered, washed with water until neutral, and then dried. 25.4 g of crude 1-nitroanthraquinone was obtained. The composition of this product is 79.0% 1-nitroanthraquinone and 1,5-dinitroanthraquinone.
1.4%, 1,8-dinitroanthraquinone 2.0g,
The amount of unreacted anthraquinone was 1.7%. The amount of methylene chloride recovered was 4.8 g.

Example 3 Add 20.8 g of anthraquinone with a particle size of 150 mesh or less to 41.6 g of 90% sulfuric acid and add 1.
Add 5.2g of 2-dichloroethane, disperse well, cool and keep warm at 15℃, and mix with nitric acid 28.5% and sulfuric acid 64.3%.
% and 7.2% water were added over 1 hour. The mixture was further stirred at this temperature for 21 hours to complete the nitration reaction. After the reaction is complete
The 1,2-dichloroethane was intermittently poured into 500 g of water kept at 80°C over 90 minutes to recover the 1,2-dichloroethane by distillation, the remaining aqueous suspension was filtered by suction, and the residue was washed with water and dried. did. 26.1 g of crude 1-nitroanthraquinone was obtained. The composition of this product was 78.1% 1-nitroanthraquinone, 3.3% 1,5-dinitroanthraquinone, 2.4% 1,8-dinitroanthraquinone, and 1.8% anthraquinone.

The azeotropic temperature of 1,2-dichloroethane and water was 71.9°C, and the amount of 1,2-dichloroethane recovered was 4.9 g.

Example 4 208g of anthraquinone was added to 416g of 98% sulfuric acid,
After taking a complete bath at 110-120℃, cool to 70-80℃.
60 g of 70% sulfuric acid and 40.8 g of water were added dropwise. Next 1,
After charging 20.8g of 1,2-trichloroethane,
A mixed acid consisting of 83.6 g of 98% nitric acid and 155.4 g of 91% sulfuric acid was gradually added dropwise at 20°C over 5 hours, and at the same temperature
The nitration reaction was completed by keeping the temperature for an hour. The reaction mass composition was 258 g of nitroanthraquinone (composition ratio
26.2%), sulfuric acid 591.1g (composition ratio 59.9%), nitric acid 12.9g
g (composition ratio 1.3%), 1,1,2-trichloroethane 20.8g (composition ratio 2.1%), water 103.9g (composition ratio 10.5
%).

Next, in order to completely terminate the reaction, the nitration reaction mixture to which 208 g of water was added was intermittently injected into 832 ml of water in a flask kept at 100° C. over 120 minutes. At this time, only slight foaming due to azeotropy was observed only in the injection section, and it was possible to distill 1,1,2-trichloroethane by azeotropy.

The azeotropic temperature of 1,1,2-trichloroethane and water is 86°C, and the amount of 1,1,2-trichloroethane recovered by distillation and separation in this way was 19.8g (recovery rate 95 %).

Comparative Example A nitration reaction mixture obtained by adding 208 g of water to the reaction mass obtained in Example 4 after completion of the nitration reaction was discharged into 832 ml of water.

Next, in order to distill and recover 1,1,2-trichloroethane, the drained liquid was gradually heated.
Near the azeotropic point of 1,1,2-trichloroethane and water, intense foaming occurs, and nitroanthraquinone is pushed up to the top of the distiller, producing 1,1,2-trichloroethane.
Recovery of trichloroethane was not practicable.

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Claims (1)

[Claims] 1. When anthraquinones are nitrated in the coexistence of halogenated aliphatic hydrocarbons and halogenated aliphatic hydrocarbons are recovered from the resulting reaction mass, the halogenated aliphatic hydrocarbons and water used in the nitration reaction are A method for producing nitroanthraquinones, which comprises intermittently injecting or dropping a nitration reaction liquid into water kept at a temperature above the azeotropic point, cooling and separating the azeotropic fraction. A method for recovering halogenated aliphatic hydrocarbons.