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Synthesis method for 2,5-dichloronitrobenzene

A technology of dichloronitrobenzene and a synthesis method is applied in the directions of nitro compound preparation, organic chemistry, etc., to achieve the effects of increasing reaction rate, increasing mass transfer rate, and reducing acid concentration

Inactive Publication Date: 2013-04-17
XIAMEN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

2,5-Dichloronitrobenzene is an intermediate for synthesizing pesticides, medicines, dyes and other chemical raw materials, and it is also a highly efficient nitrogen fertilizer synergist, which has the effect of nitrogen fixation and fertilizer preservation [6] .At present, 2,5-dichloronitrobenzene still uses high-concentration mixed acid as the nitration method in the industry, and there are few reports on the use of phase transfer catalysts in the nitration reaction, especially the nitration reaction of passivated aromatics.

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  • Synthesis method for 2,5-dichloronitrobenzene
  • Synthesis method for 2,5-dichloronitrobenzene
  • Synthesis method for 2,5-dichloronitrobenzene

Examples

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Effect test

Embodiment 1

[0020] Example 1: Add 25g of p-dichlorobenzene and 0.1g of dodecyltrimethylammonium chloride into a 250mL three-necked flask, put it in a water bath and preheat it to 80°C, add 20mL of 95% concentrated sulfuric acid 4.5 Add 12.5mL of 95% concentrated nitric acid slowly with a constant pressure titration funnel, mechanically stir at a constant temperature for 4h to stop the reaction, use a separatory funnel to separate the oil phase and water phase while hot, and oxidize the upper oil phase with 1moL / L of hydrogen Wash with sodium several times to make the pH = 7-8, then wash with deionized water several times to make the pH neutral, and obtain a light yellow liquid that turns into a light yellow solid after natural cooling at room temperature. Using GC-9160 gas chromatography and SE-54 capillary column to analyze the composition of the product, the content of the target product is about 95.58%. Embodiment 1 product gas chromatogram analysis chart is referring to Figure 5 . ...

Embodiment 2

[0021] Example 2: Add 25g of p-dichlorobenzene and 0.1g of cetyltrimethylammonium bromide to a 250mL three-necked flask, put it in a water bath and preheat it to 80°C, add 20mL of 95% concentrated sulfuric acid 4.5 Add 12.5mL of 95% concentrated nitric acid slowly with a constant pressure titration funnel, mechanically stir at a constant temperature for 4h to stop the reaction, use a separatory funnel to separate the oil phase and water phase while hot, and oxidize the upper oil phase with 1moL / L of hydrogen Wash with sodium several times to make the pH = 7-8, then wash with deionized water several times to make the pH neutral, and obtain a light yellow liquid that turns into a light yellow solid after natural cooling at room temperature. Using GC-9160 gas chromatography and SE-54 capillary column to analyze the composition of the product, the content of the target product is about 84.68%. Embodiment 2 product gas chromatogram analysis chart is referring to Figure 6 .

Embodiment 3

[0022] Example 3: Add 25g of p-dichlorobenzene and 0.1g of trioctylmethylammonium chloride into a 250mL three-necked flask, put it in a water bath and preheat it to 80°C, add 20mL of 95% concentrated sulfuric acid and 4.5mL of Water, slowly add 12.5 mL of 95% concentrated nitric acid with a constant pressure titration funnel, mechanically stir at a constant temperature for 4 hours to stop the reaction, use a separatory funnel to separate the oil phase and water phase while hot, and wash the upper oil phase with 1 mol / L sodium hydroxide Several times to make the pH = 7-8, and then wash with deionized water several times to make the pH neutral, and the obtained light yellow liquid turns into a light yellow solid after natural cooling at room temperature. GC-9160 gas chromatography and SE-54 capillary column were used to analyze the composition of the product, and the content of the target product was 100%. Embodiment 3 product gas chromatogram analysis chart is referring to Fi...

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Abstract

The invention provides to a synthesis method for 2,5-dichloronitrobenzene, and relates to 2,5-dichloronitrobenzene and the method has optimized technical conditions and adopts a phase transfer catalyst. The synthesis method comprises the following steps of: 1) mixing nitric acid, sulfuric acid, santochlor and the phase transfer catalyst for reaction so as to obtain a faint yellow liquid; and 2) separating the faint yellow liquid prepared in the step 1), washing the liquid at an upper layer with a sodium hydroxide solution to regulate the pH value of the liquid to be equal to 7-8, then washing with water to regulate to the pH value to be neutral, and cooling so as to obtain 2,5-dichloronitrobenzene. The prepared product can be analyzed by GC-9160gas chromatography, and the purity of the product is above 99%. The mass transfer rate between two phases in nitration can be greatly improved by adding a small quantity of phase transfer catalyst in the nitrifying process, so that the reaction rate is improved under the same condition and the concentration of the acid is lowered.

Description

technical field [0001] The present invention relates to 2,5-dichloronitrobenzene, in particular to a synthesis method of 2,5-dichloronitrobenzene. Background technique [0002] The traditional nitration process (nitric acid mixed acid nitration) requires extremely high acid concentration, while the new solid acid catalyst has extremely low nitration activity for nitration reactions, especially for aromatic hydrocarbons with passivating groups, so it is difficult to industrialize [1-2] . Phase transfer catalysts have been used in hydrolysis, regioselectivity of Diels-alder reactions, nucleophilic substitution of arenes, reduction, oxidation [3-5] It has been applied in such reactions, and the conversion rate, rate and selectivity of the reaction have been greatly improved. 2,5-Dichloronitrobenzene is an intermediate for the synthesis of chemical raw materials such as pesticides, medicines, and dyes. It is also a high-efficiency nitrogen fertilizer synergist, which has the e...

Claims

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Application Information

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IPC IPC(8): C07C205/12C07C201/08
Inventor 曹志凯吴建军师佳江青茵周华
Owner XIAMEN UNIV