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

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Reaction Steps

To a suspension of 4-[(2,4-dichloro-3-fluorophenyl)carbonyl]-2-piperazinone (I37) (0.25 g, 0.859 mmol) in anhydrous Dichloromethane (DCM) (2.147 ml) was added triethyloxonium tetrafluoroborate (0.179 g, 0.945 mmol) and the mixture was stirred overnight at room temperature under argon. The white suspension turned to a solution and 4-(methyloxy)-2-pyridinecarbohydrazide (0.158 g, 0.945 mmol, commercially available from e.g. Matrix Scientific, Anichem or 3B Scientific) was added at once. It was a suspension at first but straight after it changed to a yellow solution. After ½ hour a precipitate formed again. LCMS showed that the major product was the intermediate and very little unreacted starting amide was present.

Provenance & Evidence