Synthesizing, separating and purifying method for 6-nitryl-3-hydroxyl-2-pyridinecarboxylic acid

A technology of picolinic acid and purification method, applied in the field of synthesis, separation and purification of 6-nitro-3-hydroxy-2-picolinic acid, can solve the problems of difficult separation, failure to achieve separation purpose, etc., and achieves low process cost and good economy Benefit and social benefit, the effect of facilitating industrial application

CN104016912AInactive Publication Date: 2014-09-03XIHUA UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2014-09-03
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a synthesizing, separating and purifying method for 6-nitryl-3-hydroxyl-2-pyridinecarboxylic acid. The synthesizing, separating and purifying method comprises the following steps: with 3-hydroxyl-2-pyridinecarboxylic acid as a starting material, concentrated sulfuric acid as a solvent and concentrated nitric acid a nitration reagent, in the catalytic presence of a combination catalyst, carrying out a nitration reaction to generate a nitration reaction mixture (the mixture containing 6-nitryl-3-hydroxyl-2-pyridinecarboxylic acid and 4-nitryl-3-hydroxyl-2-pyridinecarboxylic acid), and separating and purifying the mixture to obtain the high-purity 6-nitryl-3-hydroxyl-2-pyridinecarboxylic acid.
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Description

[0001] technical field

[0002] The present invention relates to a method for the synthesis, separation and purification of 6-nitro-3-hydroxy-2-pyridinecarboxylic acid, more precisely, the synthesis, separation and purification of 6-nitro- 3-Hydroxy-2-pyridinecarboxylic acid method. Background technique

[0003] Picolinic acid is an important fine chemical intermediate and is widely used in the fields of medicine and pesticides. Hydroxyl-containing picolinic acid is widely used in fine chemicals, medicine, pesticides, functional materials and other fields due to the reactive characteristics of hydroxyl and carboxyl. Existing a large number of documents report the synthesis and synthesis of 3-nitro-2-hydroxybenzoic acid (i.e. 3-nitrosalicylic acid) or 5-nitro-2-hydroxybenzoic acid (i.e. 5-nitrosalicylic acid) application. For example: Literature (Tetrahedron, 2013 , vol. 69, nb 42 P8929 – 8935) reported that 5-nitrosalicylaldehyde was used as the main starting mate...

Examples

Embodiment 1

[0033] Embodiment 1: the synthesis containing 6-nitro-3-hydroxyl-2-pyridinecarboxylic acid mixture

[0034] Add 300 ml of concentrated sulfuric acid, 69.56 g (0.5 mol) of 3-hydroxy-2-pyridinecarboxylic acid, 6.96 g of catalyst cuprous chloride, and catalyst cerium nitrate (Ce(NO 3 ) 3 ) 13.91g, under stirring, use an ice-salt bath to control the temperature of the reaction system at 2-5°C, slowly add 60.0g of concentrated nitric acid dropwise for 3 hours, and continue the reaction at 2-5°C for 1 hour after the dropwise addition. Slowly raise the temperature to 40°C and react for 3 hours. After liquid chromatography monitors that the conversion rate of the raw material 3-hydroxy-2-pyridinecarboxylic acid is greater than 99.5%, stop the reaction, lower it to room temperature, and pour the reaction solution into 3 kg of crushed In ice, filter with suction, wash the filter cake with a small amount of ice water, and dry the water to obtain 81.06 g of gray solid (analysis by high p...

Embodiment 2

[0035] Embodiment 2: the synthesis containing 6-nitro-3-hydroxyl-2-pyridinecarboxylic acid mixture

[0036] 300 ml of concentrated sulfuric acid, 69.56 g (0.5 mol) of 3-hydroxy-2-pyridinecarboxylic acid, 3.48 g of catalyst cuprous chloride, 3.48 g of catalyst cerium nitrate (Ce(NO 3 ) 3 ) 6.96g, under stirring, use an ice-salt bath to control the temperature of the reaction system at 2-5°C, slowly add 60.0g of concentrated nitric acid dropwise for 3 hours, and continue the reaction at 2-5°C for 1 hour after the dropwise addition. Slowly raise the temperature to 40°C and react for 3 hours. After liquid chromatography monitors that the conversion rate of the raw material 3-hydroxy-2-pyridinecarboxylic acid is greater than 99.5%, stop the reaction, lower it to room temperature, and pour the reaction solution into 3 kg of crushed In ice, filter with suction, wash the filter cake with a small amount of ice water, and dry the water to obtain 77.04 g of gray solid (analysis by high ...

Embodiment 3

[0037] Embodiment 3: the synthesis containing 6-nitro-3-hydroxyl-2-pyridinecarboxylic acid mixture

[0038] Add 300 ml of concentrated sulfuric acid, 69.56 g (0.5 mol) of 3-hydroxy-2-pyridinecarboxylic acid, and 6.96 g of catalyst cuprous chloride into a 1000 ml three-necked flask equipped with mechanical stirring, and use an ice-salt bath to dissolve the The temperature of the reaction system was controlled at 2-5°C, and 60.0g of concentrated nitric acid was slowly added dropwise for 3 hours. After the dropwise addition, the reaction was continued at 2-5°C for 1 hour, and the temperature was slowly raised to 40°C for 4 hours. Liquid chromatography After monitoring that the conversion rate of the raw material 3-hydroxy-2-pyridinecarboxylic acid is greater than 99.1%, stop the reaction, lower it to room temperature, and pour the reaction solution into 3 kg of crushed ice under stirring, filter with suction, and use a small amount of ice water to filter the cake. Wash and dry th...