A kind of synthetic method of 2,3-dichloropyridine

A synthesis method and a technology for dichloropyridine, which are applied in the field of preparation of organic compounds, can solve the problems of expensive raw materials, many returned materials, and large amount of waste water, and achieve the effects of reducing production costs, avoiding cost input, and reducing process costs.

Active Publication Date: 2018-07-17
JIUJIANG SHANSHUI TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the chlorination-dechlorination method disclosed above solves the problems of large amount of wastewater in the diazo-chlorination method, it still has expensive raw materials, limited sources, and is easy to be monopolized by the industry. Low, repeated rectification in multi-stage rectification towers is required to obtain qualified 2,3-dichloropyridine

Method used

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  • A kind of synthetic method of 2,3-dichloropyridine
  • A kind of synthetic method of 2,3-dichloropyridine
  • A kind of synthetic method of 2,3-dichloropyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Mix 790 kilograms of pyridine, 3950 kilograms of water and 80 kilograms of iron powder, continuously feed 3000 kilograms of chlorine gas at 120 ~ 230 ° C, stir until the reaction is completed, stand and separate layers, and obtain 1500 kilograms of pyridinium chloride (II);

[0035] 1500 kg of pyridinium chloride (II) was mixed with 1500 kg of water, allowed to stand and separated to obtain 1440 kg of pyridinium chloride (II);

[0036] With 1440 kg of pyridinium chloride (II) and 5000 kg of water, 7.2 kg of nanometer IrO 2 -ZnO-MnO 2 Composite catalyst and 420 kg of pyridine are mixed, and the reaction is complete at 40~60°C and hydrogen pressure of 0.3~0.5MPa, and the nano-IrO is recovered by filtration. 2 -ZnO-MnO 2 Composite catalyst, the filtrate was separated by standing, and the oil layer was washed with 200 kg of water to obtain 1035.9 kg of 2,3-dichloropyridine with a purity of 98.3%;

[0037] 1035.9 kg of 2,3-dichloropyridine with a purity of 98.3% was purif...

Embodiment 2

[0045] Under the condition of 180~220℃ and ultraviolet light irradiation, the mixed steam of 790 kg of pyridine and 7900 kg of water is contacted with 3000 kg of chlorine gas to react; the mixed gas generated enters the reactor fixed with iron powder, and the chlorination product is collected , cooling, standing and stratifying to obtain 1560 kg of pyridinium chloride (II);

[0046] With 1560 kg of pyridinium chloride (II) and 7800 kg of water, 10 kg of nanometer IrO 2 -ZnO-MnO 2 Composite catalyst and 700 kg of sodium carbonate are mixed, under the conditions of 30~40℃ and hydrogen pressure of 0.3~0.5MPa, the reaction is complete, and the nano-IrO is recovered by filtration 2 -ZnO-MnO 2 Composite catalyst, the filtrate obtained 1050 kg of 2,3-dichloropyridine with a purity of 97.6% through standing and layering;

[0047] 1050 kg of 2,3-dichloropyridine with a purity of 97.6% was purified by rectification to obtain 903 kg of colorless and transparent 2,3-dichloropyridine wi...

Embodiment 3

[0055] Under the condition of 200~280℃ and ultraviolet light irradiation, the mixed steam of 790 kg of pyridine and 7900 kg of water is contacted with 3000 kg of chlorine gas to react; the mixed gas generated enters the reactor fixed with iron powder, and the chlorination product is collected , cooling, standing and stratifying to obtain 1430 kg of pyridinium chloride (II);

[0056] 1430 kg of pyridinium chloride (II) was mixed with 2860 kg of water, allowed to stand and separated to obtain 1380 kg of pyridinium chloride (II);

[0057] With 1380 kg of pyridinium chloride (II) and 6900 kg of water, 69 kg of nanometer IrO 2 -ZnO-MnO 2 Composite catalyst, 1380 kg of calcium carbonate mixed, under the condition of 60~80℃, hydrogen pressure of 0.8~1.0MPa, the reaction is complete, and the nano-IrO is recovered by filtration 2 -ZnO-MnO 2 Composite catalyst, the filtrate obtained 750 kilograms of 2,3-dichloropyridine with a purity of 93.3% through static stratification;

[0058] ...

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Abstract

The invention discloses a synthetic method of 2,3-dichloropyridine(III). The synthetic method of 2,3-dichloropyridine comprises the following steps: (1) taking pyridine (I) as a main starting raw material, taking water or water vapor as a reaction medium, reacting the pyridine with chlorine completely in the presence of a chlorination inducer to obtain pyridine chloride (II) as a reaction raw material for the next step; (2) taking the pyridine chloride (II) obtained from the first step as the reaction raw material, taking water or water vapor as a reaction medium, enabling the pyridine chloride (II) to be in contact with hydrogen in the presence of an acid-bining agent and a catalyst, and carrying out catalyzed hydrogeneration reduction reaction to obtain the 2,3-dichloropyridine (III) of which the purity is 99% or above, wherein the catalyst is a nano IrO2-ZnO-MnO2 composite catalyst. A reaction equation is as shown in the specification, wherein n ranges from 2 to 5. The synthetic method of 2,3-dichloropyridine has the advantages of high reaction conversion, high selectivity, stable product quality, simplicity in production and operation, low cost and the like, and the shortcomings that the quality of the 2,3-dichloropyridine (III) obtained by an existing synthetic method is not stable, and the quality of the 2,3-dichloropyridine (III) can reach up to the standard after the 2,3-dichloropyridine (III) is rectified repeatedly necessarily are overcome.

Description

technical field [0001] The invention relates to a method for preparing organic compounds, in particular to a method for synthesizing 2,3-dichloropyridine. Background technique [0002] Pyridine chloride, such as 2-chloropyridine, 2,3-dichloropyridine, 2,6-dichloropyridine, 2,3,5-trichloropyridine, etc. are important fine chemical synthesis intermediates, widely used in pesticides , The field of pharmaceutical production. Among them, 2,3-dichloropyridine is a kind of pyridine chloride with wide application and large dosage among the 6 kinds of dichloropyridine isomers, and it is the key intermediate of the new insecticide chlorantraniliprole, 2,3 , 5-Trichloropyridine is the main raw material for the synthesis of herbicides oxaflufefen, clodinafop-propargyl and clodinafop-propargyl which have excellent control effects on sagegrass, oats, ryegrass and foxtail. [0003] Currently, there are two main methods for producing 2,3-dichloropyridine. The first one, referred to as "d...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/61B01J23/656
CPCB01J23/002B01J23/6562B01J2523/00C07D213/61B01J2523/27B01J2523/72B01J2523/827
Inventor 邵玉田柳燕青
Owner JIUJIANG SHANSHUI TECH
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