反应详情

1.19 g of methyl 2-azido-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate (racemate A) and 1.31 g of triphenylphosphine in 25 ml of dioxane were stirred at room temperature for 1 hour and the mixture was then evaporated. The residue was treated with 40 ml of 2N aqueous ammonia at 50° C. for 2.5 hours and the precipitated triphenyl phosphine oxide was removed by filtration. Evaporation then yielded 0.756 g (76%) of 2-amino-hexahydro-3-oxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylic acid (racemate A) in the form of a white solid which, after recrystallization from aqueous methanol, melted at 245°-246° C. (decomposition).

1. customthe mixture was then evaporated
2. additionThe residue was treated with 40 ml of 2N aqueous ammonia at 50° C. for 2.5 hours
3. customthe precipitated triphenyl phosphine oxide was removed by filtration
4. customEvaporation