Preparation and application background and overview of 2-(1H-pyrazol-3-yl)pyridine
2-(1H-pyrazol-3-yl)pyridine is an organic intermediate that can be used to prepare a pyrazolidinol-copper complex. This complex is a mononuclear Cu complex and has anti-tumor activity.
Preparation and application of 2-(1H-pyrazol-3-yl)pyridine
Step 1. Add 40ml DMF-DMA to a 250ml three-necked flask, then add 24.2g 2-acetylpyridine, heat to 126.1~126.3°C, stir and reflux for 16 hours, cool, and concentrate the solution under vacuum to remove the solvent to obtain a crude yellow solid. Product, the yellow solid crude product is recrystallized with CHCl3-n-hexane. CHCl3-n-hexane is prepared by volume of CHCl3 and n-hexane. It was prepared with a ratio of 1:1. After recrystallization, 21.95g of yellow 1-(2-pyridyl)-3-dimethylamino-2-propenone crystals were obtained, with a yield of about 75.7%;
Step 2. Add 17.62g of 1-(2-pyridyl)-3-dimethylamino-2-propenone into a 250ml three-necked flask, then add 20ml of ethanol with a mass concentration of 95%, and stir magnetically For the reaction solution, measure 34 ml of hydrazine hydrate with a mass concentration of 85% and add it to 10 ml of ethanol with a mass concentration of 95% and mix well. After mixing, add dropwise to the reaction solution using a constant pressure dropping funnel. , after the dropwise addition is completed, heat to 121.8-122.1°C and reflux for 1 hour, distill under reduced pressure and concentrate until the volume of the reaction solution is 9-11 ml, then add 100 ml of distilled water, cool overnight, a white precipitate will precipitate, filter with suction, and dry to obtain a white solid crude product. The white solid crude product was recrystallized with acetone. After recrystallization, 9.06g of 2-(1H-pyrazol-3-yl)pyridine white crystals were obtained, with a yield of about 62.4%;
Preparation and application of 2-(1H-pyrazol-3-yl)pyridine
2-(1H-pyrazol-3-yl)pyridine is an organic intermediate that can be used to prepare a pyrazolidinol-copper complex:
1) Add 50ml of toluene and 1g of 2-(1H-pyrazol-3-yl)pyridine into a 250ml three-necked flask, add 10ml of NaOH solution with a mass concentration of 28 to 30% and a mass concentration of 28 to 30% under magnetic stirring. 10% n-Bu4NOH solution 1ml, heated to 69~72℃ and refluxed for 1.5h, then add 0.85g of 1,3-dichloro-2-propanol dropwise, 69~72℃ Continue to reflux for 45 hours, cool to room temperature, separate the magnesium carbonate mechanical phase, rinse the solid phase with water, and then extract with CHCl3. After the extraction is completed, remove CHCl3 under vacuum conditions. The crude product is obtained, and the crude product is recrystallized with CHCl3-n-hexane. CHCl3-n-hexane is reacted with CHCl3 and n-hexane. It was prepared with a volume ratio of 1:1. After recrystallization, 1.74g of colorless needle-like crystals of 1,3-bis[3-(2-pyridine)pyrazole]-2-propanol was obtained, with a yield of approximately 73%;
2) Dissolve 0.14g 1,3-bis[3-(2-pyridine)pyrazole]-2-propanol in 10ml methanol, add 0.016g NaOH under magnetic stirring, stir for 30min, and then drop by drop Add copper bromide-methanol solution. The copper bromide-methanol solution is prepared by dissolving 0.089g copper bromide in 5 ml methanol. Continue stirring the reaction at room temperature for 1 hour, then filter to obtain a green filtrate. The filtrate naturally evaporates at room temperature. Until methyltetrahydrofuran is completely separated from the flaky crystals, a pyrazolidinol-copper complex with the molecular formula CuLBr·4H2O is obtained, in which L is 1,3-bis[3-(2-pyridine)pyrazole]-2-propanol. alcohol.
References
[1][Chinese invention] CN201210242532.7 A pyrazolidinol-copper complex and its preparation method and application
