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

Participants

Reaction Conditions

Reaction Steps

4-[(2,4-Dichloro-3-fluorophenyl)carbonyl]-2-piperazinone (I37)(0.3 g, 1.031 mmol) was dissolved in Dichloromethane (DCM) (2.58 ml). triethyloxonium tetrafluoroborate (0.235 g, 1.237 mmol) was added and the solution was left to stir, under an argon atmosphere for 30 minutes. 3-Fluoro-2-pyridinecarbohydrazide (I31) (0.192 g, 1.237 mmol) was added and the solution was left to stir for a further 40 minutes. The solvent was removed under reduced pressure and 1-butanol (2.58 ml) was added. The reaction mixture was left to reflux at 120° C., under an argon atmosphere for 3.5 hours. The solvent was removed under reduced pressure to afford crude product in 0.887 g. The crude material was purified by flash chromatography (Biotage Isolera 4, 50 g cartridge) with a gradient of MeOH 0-10% in DCM. The solvent was removed under reduced pressure to afford 0.254 g of the desired compound. The isolated material was purified using MDAP to afford the purified product in 0.110 g.

Provenance & Evidence