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Preparation method of 3-hydroxypyridine

A technology of hydroxypyridine and pyridine, applied in the field of preparation of 3-hydroxypyridine, can solve problems such as polluting the environment and unfavorable environmental protection, and achieve the effects of reducing pollutants, less waste liquid and waste gas, and being beneficial to green production

Inactive Publication Date: 2014-03-26
常熟市联创化学有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the process of traditional synthesis of 3-hydroxypyridine, a large amount of organic waste liquid will be produced, and the discharge of these waste liquids into the environment will pollute the environment and is not conducive to environmental protection

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] A kind of preparation method of 3-hydroxypyridine is provided, comprising the steps of:

[0015] (1) Mix pyridine and mercuric sulfate in fuming sulfuric acid, heat and react at 210°C for 9 hours, cool and add ethanol to precipitate crystals to obtain pyridine-3-sulfonic acid;

[0016] (2) Heat the mixture of pyridine-3-sulfonic acid and basic substance obtained in step (1) to a molten state. The heating temperature is 160°C, and then heat up for 2 hours. The heating temperature is 250°C. Use for cooling Saturated sodium carbonate solution was used to adjust the pH value to 8, and after treatment, 3-hydroxypyridine was obtained.

Embodiment 2

[0018] A kind of preparation method of 3-hydroxypyridine is provided, comprising the steps of:

[0019] (1) Mix pyridine and mercuric sulfate in oleum, heat and react at 215°C for 10 hours, cool and add methanol to precipitate crystals to obtain pyridine-3-sulfonic acid;

[0020] (2) Heat the mixture of pyridine-3-sulfonic acid and basic substance obtained in step (1) to a molten state, the heating temperature is 160°C, and then heat up to react for 2.5 hours, the heating temperature is 250°C, use for cooling The saturated sodium carbonate solution was used to adjust the pH value to 9, and after treatment, 3-hydroxypyridine was obtained.

Embodiment 3

[0022] A kind of preparation method of 3-hydroxypyridine is provided, comprising the steps of:

[0023] (1) Mix pyridine and mercuric sulfate in oleum, heat and react at 220°C for 8 hours, cool and add water to precipitate crystals to obtain pyridine-3-sulfonic acid;

[0024] (2) Heat the mixture of pyridine-3-sulfonic acid and basic substance obtained in step (1) to a molten state, the heating temperature is 160°C, and then heat up for reaction for 3 hours, the heating temperature is 250°C, use for cooling A saturated sodium carbonate solution was used to adjust the pH value to 8.7, and post-treatment was performed to obtain 3-hydroxypyridine.

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PUM

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Abstract

The invention discloses a preparation method of 3-hydroxy-pyridine. The method comprises the following steps: mixing pyridine and mercury sulfate in fuming sulfuric acid, heating at 210-220 DEG C for reaction for 8-10 h, cooling and adding a solvent to precipitate crystals, so as to obtain pyridine-3-sulfonic acid; and heating a mixture of the pyridine-3-sulfonic acid obtained in the step (1) and alkaline substances into a molten state, then heating and reacting for 2-3 h, cooling, adjusting the value to 8-9 and conducting posttreatment to obtain 3-hydroxypyridine. Through the above way, the preparation method of 3-hydroxypyridine provided by the invention produces little waste liquid and waste gas in the preparation process, greatly reduces the pollutants discharged into the environment, and is conducive to the green production and suitable for large-scale promotion and application. The obtained 3-hydroxypyridine with high purity can be directly applied to the subsequent production.

Description

technical field [0001] The invention relates to the field of fine organic synthesis, in particular to a preparation method of 3-hydroxypyridine. Background technique [0002] 3-Hydroxypyridine has the molecular formula C 5 h 5 NO, with a molecular weight of 95.1, is an irritating substance that can irritate the eyes, respiratory system and skin. 3-Hydroxypyridine has a melting point of 125-128°C and a boiling point of 180°C. It is a light yellow or light brown crystalline powder, soluble in ethanol and water, slightly soluble in ether and benzene, and becomes a red solution when met with ferric chloride. Easily decomposed in the air. [0003] 3-Hydroxypyridine has a wide range of applications. It can be used in the preparation of organic synthesis, medicine and dyes, as a pharmaceutical intermediate, and can be used in 3-methoxy-2-pyridinaldehyde, 3-(N,N-di In the synthesis of drugs such as carbamoyloxy)pyridine. The traditional process of synthesizing 3-hydroxypyridine...

Claims

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Application Information

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IPC IPC(8): C07D213/65
CPCC07D213/65
Inventor 陈雪平
Owner 常熟市联创化学有限公司