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Synthesis method of 3-chloro-2-hydrazinopyridine

A hydrazinopyridine and synthetic method technology, which is applied in the field of preparation of pharmaceutical and pesticide intermediates, can solve the problems of low product yield, high equipment requirements, and many steps, and achieve high product purity and yield, low equipment requirements, etc. High and mild reaction conditions

Active Publication Date: 2022-02-18
SUZHOU KAIYUAN MINSHENG SCI & TECH CORP
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Problems solved by technology

The hydrogenation reaction process is required in the above two synthetic methods, but the use of catalysts in the hydrogenation reaction and the operation process of the hydrogenation reaction are relatively dangerous, industrial production has certain dangers, and the hydrogenation reaction has higher requirements for equipment. Especially the high pressure hydrogenation reaction has higher requirements
[0005] As another example, in the invention patent application CN103588705A, 2-fluoro-3-chloropyridine and hydrazine hydrate are mixed, and ethanol is used as a solvent to react at room temperature. The reaction raw material 2-fluoro-3-chloropyridine of this method is difficult to prepare, Not suitable for industrial production
[0006] As another example, in the invention patent application CN111134128A, 2,3-dichloropyridine is used as raw material, ethanol is used as solvent, 80% hydrazine hydrate is added, slowly heated to reflux, reflux reaction is 25-30h, and the reaction is completed and cooled to room temperature, however When the reaction raw material 2,3-dichloropyridine is prepared with the prior art, nicotinamide and sodium hypochlorite are generally used to obtain 3-aminopyridine through Hoffman degradation reaction, and then chlorination reaction, diazotization and Sandmeyer The reaction is obtained. There are many steps in this reaction process, which leads to a low product yield and a large amount of labor costs. Moreover, diazotization, chlorination and more extraction operations in the reaction process will also produce a large amount of waste liquid and waste solid, which is harmful to the environment. The pollution is serious, which restricts the industrial production scale of this product, and does not meet the requirements of my country's energy saving, emission reduction and green production

Method used

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  • Synthesis method of 3-chloro-2-hydrazinopyridine
  • Synthesis method of 3-chloro-2-hydrazinopyridine
  • Synthesis method of 3-chloro-2-hydrazinopyridine

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preparation example Construction

[0032] In specific implementation, such as figure 1 Shown, the synthetic method of 3-chloro-2-hydrazinopyridine of the present invention comprises the following steps:

[0033] The first step, in the reactor, add 3-chloropyridine, the first solvent, the catalyst and stir evenly, add the sulfonation reagent, heat up the reaction; cool down after the reaction, add the second solvent, continue to cool down and then filter, the filter cake Purify by vacuum distillation to obtain 3-chloro-2-pyridinesulfonic acid.

[0034] Wherein, the first solvent is a dialkyl sulfate; the second solvent is one of ether, trichloroethylene, tetrachloropropene or any mixture thereof; the catalyst is a heavy metal sulfate; the 3-chloropyridine, The equivalent ratio of the sulfonating reagent and the catalyst is 1: (1.1-5): (0.005-0.2); the weight ratio of the 3-chloropyridine, the first solvent, and the second solvent is 1: (2-10): ( 2~10).

[0035] Specifically, first raise the temperature to 60°...

Embodiment 1

[0042] Embodiment 1, the synthesis of intermediate 3-chloro-2-pyridinesulfonic acid

[0043] Add 56.5g of 3-chloropyridine, 150g of diethyl sulfate, HgSO 4 Start stirring at 1.5g, raise the temperature to 60°C, slowly add 100g of 65% oleum dropwise, after the drop, raise the temperature to 140°C-150°C, keep the temperature for 12 hours, take samples for detection, 3-chloropyridine HPLC is 1.28%, cool down To 20°C-25°C, add 200g of diethyl ether, continue to cool down to 0°C-5°C, stir for 2 hours, filter, and filter the cake through high vacuum distillation to obtain 82.5g of the intermediate compound, with a yield of 85.67%. The intermediate compound 3-chloro-2-pyridinesulfonic acid 1 H NMR 300MHz DMSO results as shown in figure 2 shown.

Embodiment 2

[0044] The synthesis of embodiment 2,3-chloro-2-hydrazinopyridine

[0045] Add 96.7g of the intermediate 3-chloro-2-pyridinesulfonic acid, 300g of xylene, 10g of ethanolamine, 125g of 80% hydrazine hydrate into a 1000ml four-necked reaction flask, start stirring, raise the temperature to 140°C-150°C, keep it warm for 20 hours, and take a sample Detection, 3-chloro-2-hydrazinopyridine HPLC is 97.30%, then cooled to 0 ° C -10 ° C, stirred for 1 hour to start suction filtration, the filter cake was washed with 200g of water to obtain 3-chloro-2-hydrazinopyridine wet The finished product was dried with infrared light, weighed and tested to obtain 68.9g of finished product with a yield of 96.09%. The finished product 3-chloro-2-hydrazinopyridine 1 H NMR 300MHz DMSO results as shown in image 3 Shown; HPLC detection purity is 99.68%, and liquid phase chromatogram is as follows Figure 4 And shown in table 1, two-step reaction total yield is: 82.32%.

[0046] Table 1

[0047] ...

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Abstract

The invention relates to a synthesis method of 3-chloro-2-hydrazinopyridine. The method comprises the following steps: carrying out sulfonation reaction on 3-chloropyridine serving as a raw material, and reacting the obtained intermediate with hydrazine hydrate to obtain the 3-chloro-2-hydrazinopyridine. The route is simple, the average yield of the product is not lower than 80%, and the purity of the product is 99.50% or above; reaction conditions are mild, operation is safe and simple, equipment requirements are not high, and the method is suitable for industrial production; and raw materials and auxiliary materials are conventional compounds, used solvents can be recycled, the catalyst is single, industrial three wastes are few, and the method is environment-friendly.

Description

technical field [0001] The invention relates to a synthesis method of 3-chloro-2-hydrazinopyridine, which belongs to the technical field of preparation of medicine and pesticide intermediates. Background technique [0002] 3-Chloro-2-hydrazinopyridine, product CAS: 22841-92-5, molecular formula C 5 h 6 ClN 3 , with a molecular weight of 143.57, in the form of white or off-white crystals that are insoluble in water. 3-Chloro-2-hydrazinopyridine is an important intermediate for the synthesis of new ryanodine receptor insecticides, chlorantraniliprole and cyantraniliprole, and is widely used in the fields of medicine, pesticides, rubber and dyes. With the widespread use of chlorantraniliprole, especially the rapid development of my country's medicine and pesticide industries, the demand for 3-chloro-2-hydrazinopyridine is bound to increase significantly, so it is of great significance to develop a synthetic process route suitable for industrialized production. Great social a...

Claims

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Application Information

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IPC IPC(8): C07D213/77
CPCC07D213/77Y02P20/584
Inventor 孙思赵飞陈玮朱家可
Owner SUZHOU KAIYUAN MINSHENG SCI & TECH CORP
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