A method to produce 2‑ chloric acid

A technology of chloronicotinic acid and chloronicotinic acid ethyl ester, which is applied in the direction of organic chemistry, can solve environmental hazards and other problems, and achieve the effects of environmental friendliness, significant economic and social benefits, and simple operation

Active Publication Date: 2017-05-24
SHANGHAI TAIHE INT TRADE CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this route still uses chlorinating agents with increased toxicity such as phosphorus oxychloride, and by-products of equimolar dimethylamine, all of which have great harm to the environment

Method used

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  • A method to produce 2‑ chloric acid

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Experimental program
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Effect test

Embodiment 1

[0026] A method for producing 2-chloronicotinic acid, which comprises catalytic oxidation of propynyl alcohol and diisopropylamine to obtain diisopropylaminoacrolein, and then reacts with ethyl cyanoacetate to generate 2-cyano-5-diisopropylamine Base-2,4-pentadienoic acid ethyl ester, pass through dry hydrogen chloride, will obtain 2-chloronicotinic acid ethyl ester through alkaline hydrolysis, after acidification, obtain 2-chloronicotinic acid, the reaction is as follows:

[0027]

[0028] Preparation of Diisopropylaminoacrolein

[0029] 51 g of diisopropylamine 51 g, 28 g of propynyl alcohol, 2.5 g of manganese dioxide and 200 mL of toluene were sequentially added to a 0.5 L autoclave, and the reactor was closed. After raising the temperature to 80°C, feed oxygen, keep the internal pressure of the reactor at 0.1-0.2Mpa, and keep warm for 8-10h. After testing that the reaction of the raw materials is complete, filter the reaction solution, wash the filter cake with a smal...

Embodiment 2

[0037] A method for producing 2-chloronicotinic acid, adopting the following steps:

[0038] 1) propynyl alcohol and diisopropylamine are mixed and dissolved in toluene at a molar ratio of 1:1, manganese dioxide is added as a catalyst, air is passed through, and the reaction is carried out at 30°C and 2Mpa for 20 hours, the catalyst is removed by filtration, and methanol is used as solvent, and the filtrate is precipitated to obtain diisopropylamino acrolein;

[0039] 2) After dissolving diisopropylaminoacrolein in toluene, add methyl cyanoacetate and catalyst triethylamine, the molar ratio of diisopropylaminoacrolein to cyanoacetate is 1:0.95 and reflux for 6 hours, using ethanol As a solvent, get 2-cyano-5-diisopropylamino-2,4-pentadienoate through precipitation;

[0040] 3) Dissolve ethyl 2-cyano-5-diisopropylamino-2,4-pentadienoate in ethanol, pass through dry hydrogen chloride gas, the pressure of hydrogen chloride gas is 0.8Mpa, and then under the conditions of 5°C and ...

Embodiment 3

[0043] A method for producing 2-chloronicotinic acid, adopting the following steps:

[0044] 1) propynyl alcohol and diisopropylamine are mixed and dissolved in toluene at a molar ratio of 1:1, manganese dioxide is added as a catalyst, oxygen is passed through, at 60°C and 1Mpa, react for 12 hours, filter to remove the catalyst, and use toluene as solvent, and the filtrate is precipitated to obtain diisopropylamino acrolein;

[0045] 2) After dissolving diisopropylaminoacrolein in toluene, add ethyl cyanoacetate and catalyst sodium carbonate, the molar ratio of diisopropylaminoacrolein to cyanoacetate is 1:0.9 and reflux for 8 hours, using toluene as Solvent, precipitation to obtain 2-cyano-5-diisopropylamino-2,4-pentadienoate;

[0046]3) Dissolve ethyl 2-cyano-5-diisopropylamino-2,4-pentadienoate in ethanol, pass through dry hydrogen chloride gas, the pressure of hydrogen chloride gas is 1.0Mpa, and react at 20°C and 1Mpa for 18 Hours, with toluene as solvent, the oil phase...

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Abstract

The invention relates to a method for producing 2-chloro nicotinic acid. Propiolic alcohol and diisopropylamine are catalyzed and oxidized to obtain diisopropylamine acrolein. Then Konevenagel reaction is carried out to the diisopropylamine acrolein and ethyl cyanacetate to generate 2-cyan-5-diisopropylamine-2, 4-pentadiene ethyl gallate. Dried hydrogen chloride is let in, and the obtained ethyl 2-chloronicotinate is acidized to obtain 2-chloro nicotinic acid after basic hydrolysis. Compared with the prior art, the method for producing the 2-chloro nicotinic acid employs raw materials easy to purchase, has no rigor condition in the process, and is friendly to environment and suitable for industrialization production.

Description

technical field [0001] The invention relates to the field of industrial production of pesticides and pharmaceutical intermediates, in particular to a method for producing 2-chloronicotinic acid. Background technique [0002] 2-Chloronicotinic acid is a widely used pyridine pesticide and pharmaceutical intermediate. In pesticides, 2-chloronicotinic acid is mainly used to synthesize the herbicides nicosulfuron, difluzachlor and the fungicide boscalid, etc. These are new and efficient pesticide varieties, friendly to the environment, and have been widely used in domestic and foreign markets. became the dominant species. In medicine, 2-chloronicotinic acid is mainly used to synthesize anti-AIDS drug nevirapine, antidepressant drug mirtazapine, non-steroidal anti-inflammatory analgesic drug niflumic acid, nicotinic acid and so on. [0003] At present, the synthetic techniques of 2-chloronicotinic acid reported in literature and patents are as follows: [0004] 1. Patent US4081...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/803C07D213/80
CPCC07D213/80C07D213/803
Inventor 李盛林王海水卫一龙谢思勉田晓宏
Owner SHANGHAI TAIHE INT TRADE CO LTD
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