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Method for preparing nicotinic acid by pyridine dicarboxylic acid non-catalysis decarboxylation in high temperature liquid water

A technology of picolinic acid and high-temperature liquid water, which is applied in the field of carboxylic acids, can solve the problems of strict processing requirements, increased equipment investment, environmental pollution, etc., and achieves the effect of high product purity and yield, and simple reaction process

Active Publication Date: 2009-01-28
CJ CHEILJEDANG CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The obvious disadvantage of this process is that the independent reaction steps increase the equipment investment; the product separation process is complicated; the reaction process uses a large amount of strong alkali catalyst and the waste water containing sodium chloride in the by-product causes serious environmental pollution; Toxic hydrocyanic acid, strict treatment requirements; the preparation, selection and recovery of metal catalysts are not yet perfect

Method used

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  • Method for preparing nicotinic acid by pyridine dicarboxylic acid non-catalysis decarboxylation in high temperature liquid water
  • Method for preparing nicotinic acid by pyridine dicarboxylic acid non-catalysis decarboxylation in high temperature liquid water
  • Method for preparing nicotinic acid by pyridine dicarboxylic acid non-catalysis decarboxylation in high temperature liquid water

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add 300g of deionized water and 42.9g of pyridinedicarboxylic acid (the mass ratio of deionized water to pyridinedicarboxylic acid is 7:1) into a 500mL intermittent high-pressure reactor, start stirring, heat up to boiling under normal pressure, and open the exhaust valve for 3min , use water vapor to remove the air in the kettle; close the exhaust valve, continue to heat up to 160 ° C for 55 minutes; cool the decarboxylation product, add HCl solution to adjust the pH value to 3-4, and obtain crude nicotinic acid after crystallization. The crude product of nicotinic acid was decolorized by activated carbon, recrystallized, and dried in vacuum to obtain 23 g of nicotinic acid product, which was analyzed by HPLC with a purity of 98.8% (wt%) and a molar yield of 72.9%.

Embodiment 2

[0029] Add 300g of deionized water and 37.5g of pyridinedicarboxylic acid (the mass ratio of deionized water to pyridinedicarboxylic acid is 8:1) into a 500mL intermittent high-pressure reactor, start stirring, heat up to boiling under normal pressure, and open the exhaust valve for 2min , use steam to remove the air in the kettle; close the exhaust valve, continue to heat up to 150 ° C for 60 minutes; cool the decarboxylation product, add H 2 SO 4 The pH value of the solution was adjusted to 3-4, and the crude product of nicotinic acid was obtained after crystallization. The crude product of nicotinic acid was decolorized by activated carbon, recrystallized, and dried in vacuum to obtain 18.5 g of nicotinic acid product, which was analyzed by HPLC with a purity of 98.3% (wt%) and a molar yield of 67.1%.

Embodiment 3

[0031] Add 300 g of deionized water and 50 g of pyridinedicarboxylic acid (the mass ratio of deionized water to pyridinedicarboxylic acid is 6:1) into a 500 mL intermittent autoclave, start stirring, heat up to boiling under normal pressure, and open the exhaust valve for 4 minutes. Use steam to remove the air in the kettle; close the exhaust valve, continue to heat up to 170°C for 50 minutes; cool the decarboxylation product, add HCl solution to adjust the pH value to 3-4, and obtain crude nicotinic acid after crystallization. The crude product of nicotinic acid was decolorized by activated carbon, recrystallized, and dried in vacuum to obtain 28.8 g of nicotinic acid product, which was analyzed by HPLC with a purity of 99.1% (wt%) and a molar yield of 78.3%.

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Abstract

The invention discloses a method for preparing a nicotinic acid by catalysis-free decarboxylation of a dinicotinic acid in high-temperature liquid water. The method comprises the following steps: (1) deionized water and the dinicotinic acid are added to a high-pressure reaction kettle with the mass ratio of the deionized water to the dinicotinic acid being 2:1-8:1, the reaction kettle is stirred, the temperature of the reaction kettle is heated up to cause the mixture in the reaction kettle to boil, and an air exhaust valve is opened for 2-5 minutes; (2) the air exhaust valve is closed, the temperature is continuously heated up to 150-250 DEG C for decarboxylation for 5-60 minutes; (3) decarboxylate is cooled, the pH value thereof is adjusted to 3-4, and crude nicotinic acid is obtained after crystallization; and (4) a nicotinic acid product is obtained after the crude nicotinic acid is decolorized by active carbon, recrystallization and drying in vacuum. The method for preparing the nicotinic acid by catalysis-free decarboxylation has the advantages of no catalyst in the reaction process, solving the pollution problem in the existing nicotinic acid preparation, simple and pollution-free process and high product purity and yield.

Description

technical field [0001] The invention relates to carboxylic acids, in particular to a method for preparing nicotinic acid through non-catalytic decarboxylation of pyridinedicarboxylic acid in high-temperature liquid water. Background technique [0002] Nicotinic acid (Nicotinic acid, CAS No: 59-67-6), also known as nicotine acid, chemical name is pyridine-3-carboxylic acid (Pyridine-3-carboxylic acid), molecular formula C 6 h 5 NO 2 , the structural formula is: ), colorless needle-like crystals, belonging to the vitamin B family. Niacin is an indispensable nutrient for humans and animals, and an important component of coenzyme, mainly found in liver, kidney, muscle, yeast, milk, egg yolk, wheat bran, rice bran, peanuts, fruits and vegetables. [0003] As an important organic chemical raw material, niacin is widely used in medicine, food and feed industry. In the pharmaceutical industry, as a commonly used vitamin, niacin can prevent and treat various skin diseases and s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/803
Inventor 吕秀阳傅杰
Owner CJ CHEILJEDANG CORP
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