Hydrazine hydrate (1:1) → 3-cyclopropyl-4,5-dihydro-1H-pyrazol-5-one
Reaction equation
C[O:2][C:3](=O)[CH2:4][C:5]([CH:7]1[CH2:9][CH2:8]1)=O.O.[NH2:12][NH2:13]>C(O)(=O)C>[CH:7]1([C:5]2[CH2:4][C:3](=[O:2])[NH:12][N:13]=2)[CH2:9][CH2:8]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 100 °C
Procedure
To a solution of methyl-3-cyclopropyl-3-oxopropionate (10 g) and acetic acid (28 mL) in a round bottom flask under argon was added hydrazine hydrate (2.25 g). The mixture was immersed into an oil bath and heated to 100° C. overnight. The reaction vessel was then cooled and the acetic acid was evaporated in vacuo and the remaining solid was added to 1 N aqueous sodium hydroxide solution. The resulting precipitate was collected by filtration and washed with water and cold ether to afford the desired 5-cyclopropyl-2,4-dihydro-pyrazol-3-one (8.2 g) as a beige solid.