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Synthetic preparation method of 2-amino-3-nitro-4-chloropyridine

A technology of nitropyridine and chloropyridine, which is applied in the field of synthesis and preparation of 2-amino-3-nitro-4-chloropyridine, can solve problems such as reactor clogging, pyridine coking, and affecting continuous production of industrial reactions, and achieves Mild preparation conditions, high production safety, and easy industrial production

Pending Publication Date: 2021-01-22
南京麦瑞米生物技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Pyridine chloride and its derivatives are generally prepared with pyridine, ammonia, chlorine, etc. as the main raw materials. In the usual preparation process, there is obvious pyridine coking phenomenon, which leads to blockage of the reactor, thus affecting the industrial reaction. serial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Step 1: take a certain amount of pyridine and react with a chlorination reagent to obtain 4-chloropyridine;

[0032] Using pyridine as a starting material, reacting pyridine with a chlorination reagent at -5°C for 2 hours, and separating and obtaining 4-chloropyridine after the reaction is complete;

[0033] The specific steps are:

[0034] Starting material: pyridine; Organic solvent: ethyl acetate; Chlorination reagent: thionyl chloride;

[0035] Add 200g of anhydrous pyridine and 100mL of ethyl acetate in sequence in a 1000mL reaction flask, protect with nitrogen, cool in a cold water bath, slowly add 200g of thionyl chloride dropwise under stirring, and the temperature does not exceed 40°C; after the addition, keep the temperature at 70 °C for 2 hours. During this period, the color of the reaction mixture gradually became darker, and finally turned into a black oily substance. Cool down and let it stand, add 500ml of ethanol to the reaction solution, heat it at 5...

Embodiment 2

[0056] Step 1: take a certain amount of pyridine and react with a chlorination reagent to obtain 4-chloropyridine;

[0057]Using pyridine as a starting material, reacting pyridine with a chlorination reagent at 20°C for 2.2 hours, after the reaction is completed, isolating 4-chloropyridine;

[0058] The specific steps are:

[0059] Starting material: pyridine; Organic solvent: methylene chloride; Chlorinating reagent: phosphorus oxychloride;

[0060] Add 200g of anhydrous pyridine and 150mL of dichloromethane to a 1000mL reaction flask in sequence, cool in a cold water bath, slowly add 160g of phosphorus oxychloride dropwise under stirring, and the temperature does not exceed 50°C. After the addition, the temperature was raised and kept at 73°C for 5 hours. During this time, the color of the reaction mixture gradually became darker. Cool down and let it stand, add 500ml of ethanol to the residue in the lower layer, heat at 50°C and stir for 1 hour, cool down to about 10°C, ...

Embodiment 3

[0081] Step 1: take a certain amount of pyridine and react with a chlorination reagent to obtain 4-chloropyridine;

[0082] Using pyridine as a starting material, reacting pyridine with a chlorination reagent at 60°C for 2.5 hours, after the reaction is completed, isolating and obtaining 4-chloropyridine;

[0083] The specific steps are:

[0084] Starting material: pyridine; Organic solvent: chlorobenzene; Chlorinating reagent: phosphorus pentachloride;

[0085] Add 100g of anhydrous pyridine and 100mL of chlorobenzene in sequence in a 500mL reaction bottle, protect with nitrogen, cool in a cold water bath, slowly add 100g of phosphorus pentachloride dropwise under stirring, and the temperature does not exceed 30°C. After the addition, the temperature was raised and kept at 75°C for 5 hours. During this time, the color of the reaction mixture gradually became darker. Cool down and let it stand, add 300ml n-butanol to the residue in the lower layer, heat it at 60°C and stir ...

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Abstract

The invention discloses a synthetic preparation method of 2-amino-3-nitro-4-chloropyridine. The method comprises the following steps of reacting a certain amount of pyridine with a chlorination reagent to obtain 4-chloropyridine, taking a certain amount of pyridine to react with chlorine to obtain 2-chloropyridine, mixing the obtained 2-chloropyridine with ammonia gas, and reacting in a trifluoromethyl chlorobenzene solvent to obtain 2, 6-dichloropyridine, reacting the obtained 2, 6-dichloropyridine with nitric acid to obtain 2, 6-dichloro-3-nitropyridine, and putting the obtained 2, 6-dichloro-3-nitropyridine into an ethanol solution, adding 4-chloropyridine and ammonia gas, and reacting to obtain 2-amino-3-nitro-4-chloropyridine. By researching different reaction conditions and post-treatment processes, optimized process conditions are obtained, the common problems of pyridine coking and reactor blockage are solved, the industrial reaction can be continuously and safely carried out;the preparation conditions are mild, the production safety is high, and industrial production is easy; and raw materials and auxiliary materials are cheap and easily available, so that the cost can beeffectively reduced.

Description

technical field [0001] The invention relates to the technical field of fine chemical synthesis, in particular to a synthesis and preparation method of 2-amino-3-nitro-4-chloropyridine. Background technique: [0002] Pyridine chloride and its derivatives are important chemical raw materials, mainly used to prepare a series of pesticides and pharmaceutical intermediates with pyridine ring as the parent. Pyridine and its derivatives are widely distributed in nature, and are mainly used in the pharmaceutical industry to make sulfonamides, odorless ribocycin, vitamin A, cortisone, anthelmintics, local anesthetics, etc.; they are also used as stabilizers for high-grade calico, Synthetic rubber accelerator, paint solvent, condensing agent for synthetic resin; also used in the manufacture of vinylpyridine, agricultural pesticides, herbicides (paraquat), etc. [0003] Pyridine chloride and its derivatives are generally prepared with pyridine, ammonia, chlorine, etc. as the main raw ...

Claims

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Application Information

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IPC IPC(8): C07D213/73C07D213/61
CPCC07D213/61C07D213/73
Inventor 廖明
Owner 南京麦瑞米生物技术有限公司
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