Synthetic Route of 2808-86-8, With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.2808-86-8, name is 2,3,4,5-Tetrachloropyridine, molecular formula is C5HCl4N, molecular weight is 216.8801, as common compound, the synthetic route is as follows.
With a thermometer, reflux condenser,300 g of 2-chloropyridine was added to a 500 mL glass reaction vial of a chlorine tube.15g supported catalyst Sn-AC, heated to 110 C,Chlorine gas (pressure 0.1MPa) was introduced at a flow rate of 200 ml/min, and after 20 hours of reaction, the temperature was lowered to 30 C or lower.Filter to remove the supported catalyst,The obtained filtrate (HPLC detection of 2,3,4,5-tetrachloropyridine was 217 g) was placed in a glass reaction flask.And adding methanol-water mixed solvent 800mL (volume ratio 4:1),79 g of pyridine and 217 mg of activated carbon catalyst loaded with Pd (purchased from Xi’an Kaili New Materials Co., Ltd., grade 5% palladium carbon Pd/C, the same below), and the reaction system was repeatedly replaced with hydrogen three times.Then, it was heated to 50 C, and hydrogen gas (pressure 0.5 MPa) was introduced at a flow rate of 200 ml/min.At the same time, a 5% aqueous solution of Na2CO3 was added dropwise to maintain the pH of the reaction system at 8-10.HPLC analysis showed that the content of 2,3,4,5-tetrachloropyridine in the material was less than 5%, and the hydrogen was stopped.The material is lowered to normal temperature. The catalyst was filtered, and the filtrate was evaporated under reduced pressure to remove methanol, and the precipitated white solid was collected by filtration.The filter cake was washed three times with 100 mL of 5% hydrochloric acid and dried to give 465 g of white solid.HPLC analysis showed that the crude product contained 5.8% dichloropyridine and 89.8% 2,3,5-trichloropyridine.2,3,4,5-tetrachloropyridine 4.4%. The crude product was subjected to distillation under reduced pressure to obtain 414 g of 2,3,5-trichloropyridine (yield: 86.2%).The purity is greater than 99%.
Statistics shows that 2808-86-8 is playing an increasingly important role. we look forward to future research findings about 2,3,4,5-Tetrachloropyridine.
Reference:
Patent; Yancheng Heng Sheng Chemical Co., Ltd.; Huan Bin; Li Yong; Zhang Xiaohang; Cheng Ronghua; (9 pag.)CN108341767; (2018); A;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem