Pyrazine-2-Carboxylic Acid Hydrazide → 7-[(2,3-Dichloro-4-fluorophenyl)carbonyl]-3-(2-pyrazinyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine

Beteiligte Stoffe

Reaktionsschritte

4-[(2,3-dichloro-4-fluorophenyl)carbonyl]-2-piperazinone (I34) (0.210 g, 0.721 mmol) was dissolved in Dichloromethane (DCM) (3 mL), and to this was added triethyloxonium tetrafluoroborate (0.144 g, 0.757 mmol), the solution was stirred for 20 minutes before 2-pyrazinecarbohydrazide (commercially available from e.g. TimTec, J&W PharmLab or AKos Consulting, 0.120 g, 0.866 mmol) was added. The solution was then allowed to stir for an additional 30 minutes before the solvent was concentrated and n-butanol (3 mL) was added. The solution was then stirred, under argon and reflux, for 3 hours before being allowed to cool to room temperature. The solvent was then removed in vacuo and the remaining residue was purified by flash chromatography (Biotage SP4, 25M cartridge) with a gradient of 0-10% 2M NH3/MeOH in DCM. TLC confirmed product location and the solvent from the combined fractions was evaporated in vacuo. The remaining residue was then further purified by mass-directed automated HPLC, and the solvent evaporated in vacuo. The remaining residue was then triturated with ether and dried in a vacuum oven to yield the product in 0.112 g.

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