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A kind of convenient preparation method of 2,3-dichloropyridine

A technology of dichloropyridine and chlorine gas, which is applied in the direction of organic chemistry, can solve the problems of high price of 2-chloronicotinamide and unsuitability for industrialization, and achieve the effects of short process route, simple operation and high reaction selectivity

Active Publication Date: 2021-04-16
XINFA PHARMA
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although synthetic route 3 can avoid the difficult problem that 2-position chlorination easily produces side reactions, improves the purity of 2-chloro-3-aminopyridine and simplifies post-processing operation, the raw material 2-chloronicotinamide used in synthetic route 3 High price, not suitable for industrialization

Method used

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  • A kind of convenient preparation method of 2,3-dichloropyridine
  • A kind of convenient preparation method of 2,3-dichloropyridine
  • A kind of convenient preparation method of 2,3-dichloropyridine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] Embodiment 1: the preparation of 3-chloro-2-hydroxypyridine (IV)

[0047] In the 500 milliliter four-necked flask that is connected with stirring, thermometer, reflux condenser, gas guide tube and 30wt% sodium hydroxide aqueous solution absorbing device, add 160 grams of 1,2-dichloroethane, 49.5 grams (0.5 moles) of 2- Piperidone (II), 0.6 g of triethyl phosphite, heat, keep between 50-60 °C, slowly pass in 120.0 g (1.7 moles) of chlorine gas, and pass in about 3-4 hours, then 55-60 Stir and react at ℃ for 4 hours, cool to 20-25°C, add 160.0 grams (1.6 moles) of 40wt% sodium hydroxide aqueous solution, stir and react at 50-55°C for 3 hours, cool to 20-25°C, acidify the pH of the system with 30wt% hydrochloric acid 3.0-4.0, separate layers, extract the water layer with 1,2-dichloroethane 3 times, 50 grams each time, combine the organic phases, recover the solvent by distillation, and dry to obtain 59.7 grams of 3-chloro-2-hydroxypyridine as a solid (Ⅳ), the yield is 92....

Embodiment 2

[0048] Embodiment 2: the preparation of 3-chloro-2-hydroxypyridine (IV)

[0049] In the 500 milliliter four-neck flask that is connected with stirring, thermometer, reflux condenser, constant pressure dropping funnel and 30wt% sodium hydroxide aqueous solution absorption device, add 50 grams of dichloromethane, 9.9 grams (0.1 mole) 2-piperidine Ketone (II), 0.2 grams of 4-dimethylaminopyridine, 45.0 grams (0.43 moles) of 35wt% hydrochloric acid, kept at 35-40 °C and added dropwise 45.0 (0.4 moles) of 30wt% hydrogen peroxide, and the addition was completed in about 3-4 hours , then stirred at 40-45°C for 5 hours, cooled to 20-25°C, added 35.0 grams (0.35 moles) of 40wt% sodium hydroxide aqueous solution, stirred and reacted at 40-45°C for 3 hours, cooled to 20-25°C, 30wt% The pH value of the hydrochloric acid acidification system was 3.0-4.0, and the layers were separated, and the aqueous layer was extracted with dichloromethane 3 times, 50 g each time, the organic phases were ...

Embodiment 3

[0050] Embodiment 3: the preparation of 3-chloro-2-hydroxypyridine (IV)

[0051] In the 500 milliliters of four-neck flasks that are connected with stirring, thermometer, reflux condenser, gas guide tube and 30wt% sodium hydroxide aqueous solution absorption device, add 150 gram trichloroethanes, 49.5 grams (0.5 moles) 2-piperidone ( Ⅱ), 0.9 grams of triphenyl phosphite, heated, kept between 70-75 °C, slowly introduced 115.0 grams (1.62 moles) of chlorine gas, and the introduction was completed in about 3-4 hours, then stirred at 70-75 °C for 3 hour, cooled to 20-25°C, added 170.0 grams (1.7 moles) of 40wt% sodium hydroxide aqueous solution, stirred and reacted at 40-45°C for 3 hours, cooled to 20-25°C, and the pH value of the 30wt% hydrochloric acid acidification system was 3.0-4.0 , layered, the aqueous layer was extracted 3 times with trichloroethane, each 50 grams, the organic phases were combined, the solvent was reclaimed by distillation, and dried to obtain 60.4 grams o...

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Abstract

The invention provides a simple and convenient preparation method of 2,3-dichloropyridine, which uses 2-piperidone (II) as a raw material to prepare 1,3,3-trichloro-2-piperidone (III) through chlorination reaction ), and then eliminate hydrogen chloride to obtain 3-chloro-2-hydroxypyridine (IV), and then prepare 2,3-dichloropyridine (I) through a substitution reaction with a chlorinated reagent. The method of the invention has cheap and easy-to-obtain raw materials, low cost, stable reaction intermediates and raw materials, safe and convenient operation, less waste water generation, environmental protection, high reaction selectivity, few side reactions, high product yield and purity, and is suitable for industrialization Production.

Description

technical field [0001] The invention relates to a convenient preparation method of 2,3-dichloropyridine, which belongs to the technical field of fine chemicals. Background technique [0002] 2,3-Dichloropyridine (I) is an important fine chemical intermediate widely used in the preparation of medicines and pesticides, and is the key intermediate of the new insecticide chlorantraniliprole. Chlorantraniliprole is a class of phthalamide insecticides developed by DuPont that act on ryanodine receptors. This insecticide has a novel structure and a unique mode of action. It has special effects on Lepidoptera pests and is highly effective , broad-spectrum, no cross-resistance with existing pesticides, etc., low toxicity to mammals, suitable for pest control and integrated control. [0003] [0004] Chinese patent document CN103145609A uses 2,3,6-trichloropyridine as the starting material, in the presence of alcohol solvent and palladium carbon catalyst, with formate as the hydro...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D213/61C07D213/64
CPCC07D213/61C07D213/64
Inventor 戚聿新张明峰鞠立柱王全龙
Owner XINFA PHARMA
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