Application of 136888-21-6, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 136888-21-6, name is 2-Chloro-5-fluoro-3-nitropyridine, molecular formula is C5H2ClFN2O2, The compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
In a high-pressure reaction vessel, 2,3-dichloro-5-fluoropyridine 85g (0.5 mol) was added to 200 mL of ammonia water, and the temperature was set at 180 C., and the reaction under high pressure was performed for 24 h. The reaction of the starting material was complete by TLC, and the solvent was swirled to obtain 2- Chloro-5-fluoro-3-aminopyridine 65g;Place 2-chloro-5-fluoro-3-aminopyridine 65 g (0.45 mol) in a 900 mL round-bottomed flask in acetonitrile, and add 450 mL of water buffer solution (0.6 M K2CO3-4¡Á10-4 M EDTA disodium salt). 350 mL (3 mol) of acetonitrile and 290 mL (3 mol) of a 30% H2O2 aqueous solution, and the reaction mixture was stirred at room temperature for 1 hour and extracted with ethyl acetate (3 x 300 mL). The organic layers were combined and dried over anhydrous Na2SO4. The solvent was removed to give a sufficiently pure product, 2-chloro-5-fluoro-3-nitropyridine, 65 g;To a solution of 65 g (0.35 mol) of 2-chloro-5-fluoro-3-nitropyridine in DMSO/H2O (mass ratio 9:1, 3500 mL) was added L-proline 230 g (2 mol), Na2CO3 210 g (2 mol), NaN3 230 g (3.5 mol), sodium ascorbate 350 g (1.75 mol) and CuSO4.5H2O 500 g (2 mol); the mixture was stirred in an oil bath at 70C for 24 hours, and then the mixture was poured into 5000 mL of ice water to give a solid product. Filter and crystallize to obtain 47g of 2-amino-5-fluoro-3-nitropyridine; add 2-amino-5-fluoro-3-nitropyridine to the aqueous solution of sulfuric acid, add a certain amount of chloroacetic acid, and heat to 120C. After TLC monitored the reaction of the raw materials, the reaction mixture was extracted with methylene chloride. The pH of the organic phase was adjusted to 7-8 with a saturated sodium carbonate solution, and the organic phase was concentrated to obtain 2-amino-5-fluoro-pyridine.
While traditionally a conservative industry, chemical producers will need to modernize their PR strategies to stay relevant.we look forward to future research findings about 136888-21-6, 2-Chloro-5-fluoro-3-nitropyridine.
Reference:
Patent; Henan Longhu Biological Co., Ltd.; Mu Kairui; Lei Yansheng; (13 pag.)CN107827887; (2018); A;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem