Application of 2-picolinic acid_Industrial additives

Application background and overview of 2-pyridinecarboxylic acid

2-pyridinecarboxylic acid is a white to off-white powdery substance; melting point (℃): 139-142; boiling point ( ℃, normal pressure): 229.19; flash point (℃): 139; water solubility: 887g/L (20℃); solubility: easily soluble in glacial acetic acid, almost insoluble in ether, chloroform and carbon disulfide.

Applications of 2-pyridinecarboxylic acid

2-pyridinecarboxylic acid is An important organic synthesis intermediate, it is used in the pharmaceutical industry to synthesize a variety of amide and ester derivatives and has a large market demand. It is also the synthetic raw material for many 2-picolinates and has a very wide range of uses. Chromium 2-picolinate is one of the functional ingredients in health foods. If not used properly, it can reduce blood sugar levels and insulin resistance in diabetics, prevent and assist in the treatment of diabetes, and can also prevent cardiovascular and cerebrovascular diseases. It can also be used as a feed additive for livestock and poultry to accelerate their growth and development. 2-Picolinic acid is also an important chemical additive and an important corrosion inhibitor. It can also be used as a light stabilizer for light-sensitive synthetic resins.

Application and recovery method of 2-picolinic acid

A method for recovering 2-picolinic acid in 2-cyanopyridine wastewater, including the following steps:

Wastewater containing 1-10% 2-pyridinecarboxylic acid passes through the D101 resin adsorption column. The adsorption temperature is controlled at 25°C, the adsorption flow rate is controlled at 1BV/h, the height-to-diameter ratio of the resin column is 12, and the wastewater is controlled at The residence time on the adsorption resin is 10 minutes, and wastewater containing 2-picolinic acid <0.1% is obtained. The adsorbed resin is rinsed with 50% ethanol aqueous solution, the elution temperature is controlled to 30°C, and the elution speed is controlled to 0.5BV/h. The desorbed liquid is then rectified, the temperature of the distillation kettle is controlled to 80-100°C, and the reflux ratio is 1:2 to recover ethanol for elution and use to obtain a 15% 2-picolinic acid aqueous solution, which is then passed through the polysulfone polymer membrane material Enter aminomethylpyridine for membrane concentration, control the membrane separation temperature to 75°C, the pressure to 0.6Mpa, and the membrane flux to 150L/m2·h to obtain 55% 2-picolinic acid concentrate. The recovery rate of 2-picolinic acid in the wastewater is 95.5 %.

Applied synthesis method of 2-picolinic acid

Application report of 2-picolinic acid 1.

A synthesis method of 2-pyridinecarboxylic acid, including the following steps: (1) Dicyclopentadienyl cobalt , a catalyst composed of manganese acetate and cobalt acetate with a mass ratio of 10:2:1 and acetonitrile were added to the reaction kettle, dry acetylene was introduced at room temperature until the pressure of the reaction kettle rose to 1MPa, stirred and heated to 150°C, reacted for 9 hours, the reaction solution Concentrate and purify by barium carbonate distillation to obtain 2-methylpyridine;

(2) Heat the above-mentioned 2-methylpyridine on a heating bed to 350-370°C to become steam, and then mix it with ammonia 2-pyridinecarbonitrile can be produced by mixing gas, water vapor and air through catalytic oxidation through a catalyst layer. The catalyst layer includes a catalyst, a cocatalyst and a catalytic carrier. The catalyst is germanium oxide, antimony trioxide and Vanadium oxide, the cocatalyst is copper and zirconium, and the catalytic carrier is alumina;

(3) Add the above-mentioned 2-pyridinecarbonitrile to a sodium hydroxide solution with a concentration of 45% , heat to 80°C, stir and react for 6 hours, then cool to room temperature, filter with suction, wash the filter cake with water and dry to obtain crude 2-picolinic acid. Add the crude 2-picolinic acid to methylene chloride and heat Reflux and stir until it is completely dissolved, then slowly add a mixed solution of methanol and ethanol with a volume ratio of 2:1 dropwise. After the dropwise addition is completed, cool to room temperature and stir for 8 hours. Filter with suction. The filter cake is dried in an oven at 65-80°C. After that, the purified 2-picolinic acid can be obtained.

Application report 2 of 2-picolinic acid.

In a 500ml three-necked flask, add 100g of 2-cyanopyridine and 200g of ion-free water, then start stirring, raise the temperature to 50°C, add 128.2g of 30% sodium hydroxide into the flask, after the addition is completed, continue to raise the temperature, reflux the reaction for 4 hours, and then steam the water. After steaming 50g of water, the reaction solution Cool to 20°C, add 30% hydrochloric acid, adjust the pH value of the reaction solution to 2.5, then turn on the steam to heat up and steam the water until the temperature of the kettle reaches 120°C, evaporate the reaction solution to dryness, stop steaming water, and then drip it into the flask. Add 300g of absolute alcohol and maintain the temperature of the reaction solution at 55°C. After the addition is completed, stir and dissolve for 2 hours, then filter. The filtrate is cooled and crystallized to precipitate solid 2-picolinic acid. Filter and dry to obtain 2-picolinic acid. 106.0g, yield 89.6%.

References

[1] [Chinese invention] CN201911417166.2 A method for recovering 2-picolinic acid in 2-cyanopyridine wastewater

[ 2] [Invented in China] CN201710428761.0 Synthetic method of 2-picolinic acid

[3] [Invented in China] CN200910031479.4 Synthetic method of 2-picolinic acid