Triethyloxonium tetrafluoroborate → 7-[(2,3-Dichloro-4-fluorophenyl)carbonyl]-3-(3-pyridazinyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine

Participants

Reaction Conditions

Reaction Steps

4-[(2,3-Dichloro-4-fluorophenyl)carbonyl]-2-piperazinone (I34) (0.23 g, 0.790 mmol) was dissolved in Dichloromethane (DCM) (1.975 ml) and triethyloxonium tetrafluoroborate (0.180 g, 0.948 mmol) was added. The solution was left to stir under an argon atmosphere for 40 minutes. A clear solution was formed. 3-pyridazinecarbohydrazide (I23) (0.131 g, 0.948 mmol) was added and the solution was stirred under an argon atmosphere for a further 40 minutes. The solvent was removed under reduced pressure and then 1-butanol (1.975 ml) was added and the solution was left to reflux under an argon atmosphere at 120° C. for 3 hours. The reaction was followed by LCMS. The solvent was removed under reduced pressure. The crude material was purified by flash chromatography (Biotage SP4, 50 g cartridge) with a gradient of MeOH 0-10% in DCM. The solvent was removed under reduced pressure and the isolated material was purified further using MDAP. The columns were combined and the solvent removed under reduced pressure. The material was triturated with ether to afford the desired material in 27 mg.

Provenance & Evidence