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Method for purifying 2,3-dimethyl pyridine

A lutidine and purity technology, applied in the field of purifying 2,3-lutidine, can solve problems such as being unsuitable for large-scale production, complicated operation, etc., and achieve the effects of simple preparation method and high purity

Inactive Publication Date: 2012-04-11
ANHUI COSTAR BIOCHEM CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, pyridine base is mainly produced by chemical synthesis. Chemical synthesis generally uses shape-selective molecular sieves as catalysts, and is formed by catalytic gas-phase condensation reaction between aldehydes and ammonia. Purification of pyridine is generally treated by sulfuric acid, potassium hydroxide, etc. and then rectified. Obtained, or the method of potassium permanganate oxidation, and then treated with sodium hydroxide and calcium oxide, but these methods can more or less purify pyridine, but the operation is complicated and not suitable for large-scale production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0015] Example: The method for purifying 2,3-lutidine may further comprise the steps:

[0016] (1) Salt formation: Add 1000kg of ethylene glycol, 3000kg of crude 2,3-lutidine, 600kg of tetrafluoroethylene and 1200kg of ethylenediaminetetraacetic acid into the salt-forming kettle in sequence, heat up to 170-180°C and reflux, and keep for 30 After -40 minutes, cool down to room temperature, stir and crystallize for 55-65 minutes, then filter;

[0017] (2) Pour the filtrate obtained in step (1) into the reaction kettle for recrystallization, keep it at 4-6°C for 55-65 minutes, filter, and filter the solid into the salt-forming kettle to form salt;

[0018] (3) Salt-forming solid washing: soak and wash the solid after step (2) into salt with ethanol for 2-3 times, soak for 25-35 minutes each time, press filter, and take solid samples to test the purity of 2, 3-lutidine;

[0019] (4) Analysis: Add the solid obtained by pressure filtration in step (3) into the analysis kettle, add...

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Abstract

The invention discloses a method for purifying 2,3-dimethyl pyridine. The method mainly comprises the following steps of: adding ethylene glycol, tetrafluoroethylene and organic carboxylic acid to a crude product of the 2,3-dimethyl pyridine; and then sequentially salifying, crystallizing, washing, analyzing, extracting and precipitating to finally obtain the refined product of the 2,3-dimethyl pyridine. The method disclosed by the invention is simple in operation, and can be used for effectively purifying the 2,3-dimethyl pyridine; and the 2,3-dimethyl pyridine obtained by the method has the advantage of high purity.

Description

technical field [0001] The invention relates to a chemical purification method, in particular to a method for purifying 2, 3-lutidine. Background technique [0002] Pyridine is widely used in medicine, pesticide and other fields. In addition, they are also widely used in rubber industry, surfactant and dye industry, etc. Pyridine with a content of less than 99% is generally called crude pyridine and can be used as a solvent, Pyridine with a content higher than 99.5% is usually called pure pyridine and can be used in most chemical synthesis. [0003] At present, pyridine base is mainly produced by chemical synthesis. Chemical synthesis generally uses shape-selective molecular sieves as catalysts, and is formed by catalytic gas-phase condensation reaction between aldehydes and ammonia. Purification of pyridine is generally treated by sulfuric acid, potassium hydroxide, etc. and then rectified. Obtain, or first potassium permanganate oxidation, then use the method for sodium h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/16
Inventor 刘善和韦永飞杨平方磊
Owner ANHUI COSTAR BIOCHEM CO LTD