Synthetic Route of 1254073-41-0, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps,and cheap raw materials. 1254073-41-0, name is 5-Fluoropicolinohydrazide. A new synthetic method of this compound is introduced below.
To a solution of 4-[(2,3-dichloro-4-fluorophenyl)carbonyl]-2-piperazinone (I34) (5.08 g, 17.45 mmol) in Dichloromethane (DCM) (80 mL) was added triethyloxonium tetrafluoroborate (3.48 g, 18.32 mmol). The solution was then stirred under argon for 20 minutes before 5-fluoro-2-pyridinecarbohydrazide (I24) (3.25 g, 20.94 mmol) was added. The solution was then stirred for a further 3 hours, before the solvent was concentrated and n-butanol (80 mL) was added. The solution was then stirred, under reflux and argon, for 3 hours before being cooled to room temperature. The solvent was then evaporated in vacuo and the remaining residue was partioned between DCM (10OmL) and water (5OmL), before being dried over anhydrous sodium suphate. The sodium sulphate was then removed by filtration, and the solvent was evaporated in vacuo. The remaining residue was then purified by flash chromatography (Isolera 34Og cartridge) with a gradient of 0-10% MeOH in DCM, TLC confirmed product location and the solvent from the combined fractions was evaporated in vacuo. The remaining solid was then recrystallised from ethyl acetate to yield the product in 2.067 g.LCMS: m/z = 410 (M+ H)+, retention time = 0.93 minutes (2 minutes); 1H NMR (400 MHz; CDCI3) delta 8.50 ( 0.6H, d), 8.43 – 8.35 ( 1.4H, m), 7.6- 7.54 ( 1 H, m), 7.31-7.19 ( 2H,m), 5.26 ( 1 H, q), 4.82-4.64 ( 2.4H, m), 4.60 – 4.53 ( 0.4H, m), 4.36-4.14 ( 1.2H, m), 3.77-3.62 ( 1 H, m).
At the same time, in my other blogs, there are other synthetic methods of this type of compound,1254073-41-0, 5-Fluoropicolinohydrazide, and friends who are interested can also refer to it.
Reference:
Patent; GLAXO GROUP LIMITED; DEAN, David Kenneth; MUNOZ-MURIEDAS, Jorge; SIME, Mairi; STEADMAN, Jon Graham Anthony; THEWLIS, Rachel Elizabeth Anne; TRANI, Giancarlo; WALTER, Daryl Simon; WO2010/125102; (2010); A1;,
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