2, 3-dichloro-6-nitroaniline and preparation method thereof

A technology for nitroaniline and trichloronitrobenzene, which is applied in the preparation of nitro compounds, the preparation of amino compounds, chemical instruments and methods, etc., can solve the problems such as the inability to recover and apply sulfuric acid, the products are not easily separated, and the potential safety hazard is increased, and the invention is achieved. The effect of reducing environmental protection pressure, mild reaction conditions and reducing consumption

CN106854162AInactive Publication Date: 2017-06-16ZHEJIANG HISUN CHEM
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2017-06-16
Estimated Expiration
Not applicable · inactive patent

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Abstract

Belonging to the field of organic synthesis, the invention relates to 2, 3-dichloro-6-nitroaniline and a preparation method thereof. According to the invention, 2, 3-dichloro-6-nitroaniline is prepared by a two-step method. The method includes: firstly taking 1, 2, 3-trichlorobenzene as the raw material to carry out nitration reaction with nitric acid in a sulfuric acid system to prepare 2, 3, 4-trichloronitrobenzene; and then carrying out ammonolysis reaction on the 2, 3, 4-trichloronitrobenzene and ammonia water in an organic solvent at 120-150DEG C so as to obtain DCONA. The preparation method has the advantages of simple operation, mild reaction conditions, high yield and purity, and green and environment protection, and the sulfuric acid, organic solvent and ammonia water used in the preparation process can all be effectively recovered.
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Description

technical field

[0001] The invention relates to 2,3-dichloro-6-nitroaniline and a preparation method thereof, belonging to the field of organic synthesis. Background technique

[0002] The molecular formula of 2,3-dichloro-6-nitroaniline (DCONA) is C 6 h 4 C l2 N 2 o 2 , is a kind of important pesticide intermediate, in the prior art, the preparation of DCONA mainly uses o-dichlorobenzene as raw material, through nitration reaction, separates 2,3-dichloronitrobenzene and 3,4-dichloro Nitrobenzene, wherein 2,3-dichloronitrobenzene is then reduced and nitrated to synthesize the target product (Route A); the separated 3,4-dichloronitrobenzene is ammonated to synthesize the target product (Route B).

[0003]

[0004] The raw materials of this process route are easy to obtain, but the products are not easy to separate. In order to make full use of the raw materials, two sets of production processes must be designed. It is easy to cause material shifting during feeding, wh...

Examples

Embodiment 1

[0034] The preparation method of 2,3-dichloro-6-nitroaniline comprises the following steps:

[0035] Preparation of S1, 2,3,4-trichloronitrobenzene: pump 200g of 98% sulfuric acid and 1816g of 1,2,3-trichlorobenzene into the nitration reactor, start stirring, and raise the temperature of the reactor to 45 ℃, after 1,2,3-trichlorobenzene is completely dissolved, pump 551g of 98% sulfuric acid and 696g of 95% nitric acid into the header tank, and the molar ratio of nitric acid to 1,2,3-trichlorobenzene is 1.05 : 1, sulfuric acid dehydration value D·V·S is 3.2. Add the mixed acid dropwise into the nitration reaction kettle for 20 minutes. After the dropwise addition, the reaction temperature is 50°C and the heat preservation reaction is 3 hours. The material layer was washed with water, and the water layer was separated to obtain 2239g of crude 2,3,4-trichloronitrobenzene, which was directly used for feeding in the next step;

[0036] S2, the preparation of 2,3-dichloro-6-nitro...

Embodiment 2

[0039] The preparation method of 2,3-dichloro-6-nitroaniline comprises the following steps:

[0040] S1. Preparation of 2,3,4-trichloronitrobenzene: pump 250g of 98% sulfuric acid and 2179g of 1,2,3-trichlorobenzene into the nitration reactor, start stirring, and raise the temperature of the reactor to 50°C After the 1,2,3-trichlorobenzene is completely dissolved, pump 749g of 98% sulfuric acid and 875g of 95% nitric acid into the header tank, and the molar ratio of nitric acid to 1,2,3-trichlorobenzene is 1.10: 1. Sulfuric acid dehydration value D·V·S is 3.5. Add the mixed acid dropwise into the nitration reaction kettle for 30 minutes. After the dropwise addition, the reaction temperature is 55°C and the heat preservation reaction is 2.5 hours. , the material layer was washed with water, and the water layer was separated to obtain 2688g 2,3,4-trichloronitrobenzene crude product, which was directly used for feeding in the next step;

[0041] Preparation of S2, 2,3-dichloro-...

Embodiment 3

[0044] The preparation method of 2,3-dichloro-6-nitroaniline comprises the following steps:

[0045] S1. Preparation of 2,3,4-trichloronitrobenzene: pump 400g of 98% sulfuric acid and 2724g of 1,2,3-trichlorobenzene into the nitration reactor, start stirring, and raise the temperature of the reactor to 55°C ,; After the 1,2,3-trichlorobenzene is completely dissolved, pump 1,009g of 98% sulfuric acid and 1,143g of 95% nitric acid into the header tank, and the molar ratio of nitric acid to 1,2,3-trichlorobenzene is 1.15 : 1, sulfuric acid dehydration value D·V·S is 3.9. Add the mixed acid dropwise into the nitration reaction kettle for 30 minutes. After the dropwise addition, the reaction temperature is 60°C and the heat preservation reaction is 2 hours. The material layer was washed with water, and the water layer was separated to obtain 3373g of crude 2,3,4-trichloronitrobenzene, which was directly used for feeding in the next step;

[0046] Preparation of S2, 2,3-dichloro-6...