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Preparation method of 2,6-pyridinedicarboxylic acid

A technology of dipicolinic acid and hydrochloric acid, applied in the field of medicinal chemistry, can solve the problems of unsuitability for green industrial production, low yield and selectivity, inconvenient source of raw materials, etc., and achieves low cost, high yield and selectivity, and intermediate Product stabilization effect

Active Publication Date: 2019-09-13
XINFA PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] Chinese patent document CN103664767A uses 2-methyl-6-carboxypyridine as a raw material, in an organic solvent, drops potassium permanganate solution for oxidation for 10-12 hours, filters, acidifies the resulting filtrate, precipitates, and filters to obtain 2, 6-Pyridinedicarboxylic acid, but no specific yield given
[0012] The above methods all have the problems of inconvenient sources of raw materials, a large amount of acidic wastewater in the process, large environmental pollution, high cost, harsh reaction conditions, low yield and selectivity, and are not suitable for green industrial production.

Method used

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  • Preparation method of 2,6-pyridinedicarboxylic acid
  • Preparation method of 2,6-pyridinedicarboxylic acid
  • Preparation method of 2,6-pyridinedicarboxylic acid

Examples

Experimental program
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Effect test

Embodiment 1

[0043] Embodiment 1: Preparation of 2,6-pyridinedicarboxylic acid

[0044] Add 50 g of acetonitrile, 16.0 g (0.1 mole) of 1,7-pimelic acid, and 0.5 g of aluminum trichloride into a 500 ml four-neck flask connected with stirring, a thermometer, and a reflux condenser. 30 grams of chlorine gas, stirred and reacted at 50-55°C for 8 hours, cooled to 20-25°C, blown off with nitrogen for 2 hours, added 65 grams of 17wt% ammonia water, stirred and reacted at 70-75°C for 5 hours, then cooled to 20-25°C , add 30 grams of 30wt% nitric acid, stir and react at 40-45°C for 4 hours, add the reaction liquid to 200 grams of water, adjust the pH of the system to 2.5-2.0 with hydrochloric acid, filter and dry to obtain 15.0 grams of white solid 2,6-pyridine Dicarboxylic acid, liquid phase purity 99.3%, product yield 89.8%.

[0045] The NMR data of the product are as follows:

[0046] 1 HNMR (DMSO-d6, 400MHz, δ, ppm):

[0047] 8.52 (dd, 1H), 8.77 (d, 2H), 11.0 (s, 2H).

Embodiment 2

[0048] Embodiment 2: Preparation of 2,6-pyridinedicarboxylic acid

[0049]Add 100 g of chloroform, 18.8 g (0.1 mole) of dimethyl 1,7-pimelate, 0.5 g of aluminum trichloride, and feed chlorine , a total of 30 grams of chlorine gas was introduced, stirred and reacted at 30-35°C for 8 hours, cooled to 20-25°C, blown off with nitrogen for 2 hours, added 60 grams of 17wt% ammonia methanol solution, stirred and reacted at 50-55°C for 8 hours, then cooled to 20-25°C, add 20 grams of 30wt% hydrogen peroxide, stir and react at 30-35°C for 4 hours, add 45 grams of 20wt% sodium hydroxide aqueous solution, stir and react at 30-35°C for 4 hours, separate layers, and wash the organic phase with water for two Second-rate. 20 grams of water each time, combine the water phases, adjust the pH value of the water phase to 2.5-2.0 with hydrochloric acid, filter, and dry to obtain 15.3 grams of white solid 2,6-pyridinedicarboxylic acid, the liquid phase purity is 99.2%, and the product yield is 91...

Embodiment 3

[0050] Embodiment 3: Preparation of 2,6-pyridinedicarboxylic acid

[0051] In a 500 ml four-necked flask connected with stirring, a thermometer, a reflux condenser and a constant pressure dropping funnel, add 100 g of chloroform, 18.8 g (0.1 mole) of dimethyl 1,7-pimelate, 0.6 g of 40 wt% Hydrobromic acid, add dropwise a mixed liquid of 72.0 grams of bromine and 50 grams of chloroform at 30-35°C, stir and react at 30-35°C for 7 hours after dropping, cool to 20-25°C, blow off with nitrogen for 2 hours, add 60 gram of 17wt% ammonia water, stirred and reacted at 60-65°C for 6 hours, then cooled to 20-25°C, added 20 grams of 30wt% hydrogen peroxide, stirred and reacted at 30-35°C for 4 hours, then added 45 grams of 20wt% sodium hydroxide aqueous solution, Stir the reaction at 30-35°C for 4 hours, separate the layers, and wash the organic phase twice with water. 20 grams of water each time, combine the water phases, adjust the pH value of the water phase to 2.5-2.0 with hydrochlor...

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Abstract

The invention provides a preparation method of 2,6-pyridinedicarboxylic acid. The preparation method comprises the following steps: taking 1,7-pimelic acid or 1,7-pimelic acid diester (I) as a raw material to carry out a halogenation reaction to obtain 2,2,6,6-tetrahalide (II), then carrying out a cyclization reaction with ammonia to prepare a dihydropyridine derivative (III), and carrying out oxidation by an oxidizing agent or carrying out oxidation-hydrolysis to obtain the 2,6-pyridinedicarboxylic acid. According to the method disclosed by the invention, raw materials are cheap and easily available, and the preparation method is simple, is easy to implement, and is safe and environmentally friendly. The amount of wastewater is small, cost is low, the yield and selectivity are high, byproducts are fewer, and the preparation method is suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of 2,6-pyridinedicarboxylic acid, which belongs to the technical field of medicinal chemistry. Background technique [0002] 2,6-Pyridinedicarboxylic acid is an important intermediate that can be used to synthesize various medicines, pesticides and high-performance pigments. [0003] The preparation methods of 2,6-pyridinedicarboxylic acid mainly include methyl oxidation reaction method and carbonylation reaction method. [0004] 1. Preparation of 2,6-pyridinedicarboxylic acid by methyl oxidation reaction method [0005] The document "Synth. Commun. 1992, 22, 2691" utilizes the direct chemical oxidation of 2,6-lutidine to prepare 2,6-pyridinedicarboxylic acid. [0006] Chinese patent document CN103664767A uses 2-methyl-6-carboxypyridine as a raw material, in an organic solvent, drops potassium permanganate solution for oxidation for 10-12 hours, filters, acidifies the resulting filtrate, precipitates, and...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/80C07D213/803C07D213/807
CPCC07D213/80C07D213/803C07D213/807
Inventor 鞠立柱张明峰吕强三戚聿新
Owner XINFA PHARMA
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